FWD/FF Buggy [Archive] - oOple.com Forums

Origineelreclamebord

21-11-2011, 08:57 AM

I'm really disappointed that we don't see them around: FF Buggies! When I first saw these buggies a few years back (the Ryuz FF (http://img188.imageshack.us/img188/7864/55475701.jpg) for example), I fell in love with them. They are beautiful, quirky and a comeback into the 2WD scene would make things very interesting! It's not likely this will happen anytime soon as many organisations state in their rules that FF buggies are to be run amongst 4WD buggies.

Anyway, in 2009 I already set myself the task to make a basic FF buggy from a Tamiya FF01, using Tamiya DF01 suspension arms:

http://i65.photobucket.com/albums/h212/Varockshade/RSnl%20Forum%20-%20Overige/DSC00355.jpg

http://i65.photobucket.com/albums/h212/Varockshade/RSnl%20Forum%20-%20Overige/DSC00358.jpg

http://www.tamiyaclub.com/forum/index.php?showtopic=51668
http://www.tamiyaclub.com/showroom_model.asp?cid=90871

The goal was to make a conversion without making custom parts. It went rather well and it was absolutely a blast to drive, but of course with a chassis from the early to mid 90's, no slipper clutch and 70mm shocks I wasn't going to get anywhere on a track without the car falling apart.

For a while I just put the idea of making an FF buggy aside. Recently I picked this project back up, but not with the car you see above. I plan to build a new chassis that is ready for testing on the track. The screenshot below shows what I built up this weekend in Solidworks:

http://i65.photobucket.com/albums/h212/Varockshade/RSnl%20Forum%20-%20Overige/Screenshot1LowQuality.jpg

The chassis will be based on a TRF201, as I already have one (so they can share the same bulk of spares). The gearbox and front suspension will be taken from a TRF201, the front uprights and caster blocks will come from the DB01/TRF511. The front suspension arms are to be considered as Tamiya's existing buggy arms would make for a front end that's 260mm wide instead of 250mm (plus, the TRF201 driveshafts are about 5-8mm too short on each side with the existing arms). There are a few things which I need to clear up, which are how I'll mount the top end of the shocks and what steering assembly I'm going to use.

Battle_axe

21-11-2011, 10:10 AM

so do you think in low traction this will be a better choice than a mid or rear wheel drive buggy?

qatmix

21-11-2011, 10:11 AM

Cant wait to see it take shape :thumbsup:

Conrad

21-11-2011, 12:03 PM

What about mounting the motor behind the diff, inside the body. Obviously the steering system becomes a big issue then but the car would be alot more balanced than having the motor out front, no?

coleman758

21-11-2011, 12:23 PM

Id like to see the motor inboard! (Behind the diff) You could mount the servo similar to how the pred X11 is done, With the servo in the middle of the car.

daz

21-11-2011, 12:43 PM

Welshy40

21-11-2011, 06:30 PM

Anyone remember the Kyosho Maxumm FF, I had one in the 80's and it was a horrible car. All it did was wheelspin, couldnt get it to turn when on power and it jumped awful. Im guessing now with all the power we have, it will just be 10 times worse. Not trying to shoot you down or anything, just sharing my experience with them.

I agree, it was crap and didnt do well anywhere hence why it didnt sell. From a design point of view itll be fun but will be pants if you race it.

Origineelreclamebord

21-11-2011, 07:02 PM

Hehe, nice amount of replies with mixed opinions :)

My choice for the motor at the front is for several reasons:

1. Space: It will be hard to get a construction with the motor over the steering assembly, yet retaining a low CoG and a tough steering set.
2. Weight distribution: FWDs have more problems getting traction than RWDs, and considering their weight balance from front to back I guess a motor in front of the diff will work best. Plus, if the weight balance does need to be further back, it's easy to add weight inside the chassis. However, mounting them in front of the chassis is way less effective and harder to fit.

I also considered using the DEX210's parts as a base, but as I am using a TRF201 right now it's only logical to use that as a base for this - I'm on a budget after all. Plus, making the Mid motor and Rear motor options possible on an FWD chassis is a bit more complicated than an RWD chassis. I just want a chassis with some degree of thought put into it that I can use to develop a better chassis - at least, that's the plan :p

terry.sc

21-11-2011, 07:23 PM

What about mounting the motor behind the diff, inside the body. Obviously the steering system becomes a big issue then but the car would be alot more balanced than having the motor out front, no?
Because FF buggies don't work well with inboard motors.

The Maxxum had the motor behind the steering linkage, it could never put the power down. The successful Japanese FF buggies all had the motor hanging out in front, and on loose dirt tracks they they were as fast as any rwd buggy.

A few examples:
Grahoos Poprod (http://www.rc10talk.com/viewtopic.php?f=33&t=18151&p=176616&hilit=ryuz#p176616)
Old Ryuz style FFs and Bloodclods Ryuz style build (http://www.rc10talk.com/viewtopic.php?f=33&t=14454&hilit=ryuz) and on Oople (http://www.oople.com/forums/showthread.php?t=44869)
Bloodclods FF03B (http://www.rc10talk.com/viewtopic.php?f=33&t=18151&p=176616&hilit=ryuz#p176616)
A few old FF buggies in this thread (http://www.rc10talk.com/viewtopic.php?f=80&t=5595)

Origineelreclamebord

21-11-2011, 08:04 PM

+1 on Grahoo's buggy, I love the design of it! :)

http://www.youtube.com/watch?v=Obs-mJyeBnw&list=FLCRw5YFRP5RmtJOPmAAK5UQ&index=12&feature=plpp_video

Here's a video with Grahoo's original Poprod from 1988 driving in a competition (at 1:10 interview with the driver, start of race around the 2:30 mark). Notice that it's easily as quick as the RWD buggies driving around and drove around on the first place for a while before making a mistake. I know the Wild one, Falcon and Fox are not like the RC10 would've been as a competitor, but it shows their potential on video.

The potential that the Poprod shows is reflected in today's buggy regulations. Many organisations state that FWD buggies are to be driven with 4WD buggies. I recall reading this happened when some drivers started using FWD buggies for slippery tracks and RWD buggies for tracks where the RWDs could put the power down more easily.

The regulations meant the instant end for FWD buggies in competition. After all they were put into use for their performance, not for their quirky construction.

Grahoo rebuilt his Poprod a few years ago (Link (http://www.geocities.jp/feriocruise/poprod/poprod2.html)), but with a TA03 transmission and a few modern parts I believe. This and Bloodclod's FF buggy build were of great inspiration to try and build my own FF Buggy :)

Bugle

22-11-2011, 04:04 PM

jimmy

22-11-2011, 04:14 PM

Awesome project - I've also thought about making such a buggy for a long time after seeing some Japanese projects. Very cool.

Origineelreclamebord

22-11-2011, 05:28 PM

Cool project, always wanted to make a Ryuz replica but not being able to race it in 2WD class is a bummer :(
With the speeds cars go these days compared to when they got banned I can't see a FWD being faster than a RWD.

Well, considering they are some 20 years of development the RWDs got and the FWDs didn't, I doubt the FWDs will be nearly as fast. Given they would get enough development they may become more competitive. However, it's indeed likely the FWDs won't be able to keep up with RWDs like they did back then. Even more reason to let FWDs compete in the 2WD class again :)

I hope to drive it next season next to my TRF201 at a club, and hopefully I can even enter the FWD in a 2WD race or championship if it's not at a high level.

By the way, small update:

http://i65.photobucket.com/albums/h212/Varockshade/RSnl%20Forum%20-%20Overige/Screenshot2LowQuality.jpg

I changed the front suspension a bit: I decided to use DB01 suspension blocks at the rear. The reason is that I don't want the toe-out that the suspension arms get by using the TRF201 suspension blocks. Plus, it might give me extra space to move the steering rack further forward. I also made blanks for a low profile (Savox 1251MG geometry) servo and a stick pack (Team Orion 2S 4600mAh 45C LiPo) to explore the potential layouts for the chassis.

The current one I got pictured is what I have in mind. It won't deliver the greatest front weight balance, but it does allow me to move the battery backwards all the way to the rear suspension block if I need to. Plus, if it's necessary I can place under servo weights on the car :) I plan to use the steering rack fro a TLR 22 if they are durable enough (I got a thread about that in the Losi section) as they are so compact and simple.

Another thing I did was completing the structure of the gearbox. I hope it's accurate enough as it was hard to get good measurements on the critical mounting holes with some calipers and a set square. But after all it's much cheaper than having it run through a 3D scanner at a company for 100+ euros :lol:

Chalkie

25-11-2011, 08:51 PM

Well, considering they are some 20 years of development the RWDs got and the FWDs didn't, I doubt the FWDs will be nearly as fast. Given they would get enough development they may become more competitive. However, it's indeed likely the FWDs won't be able to keep up with RWDs like they did back then. Even more reason to let FWDs compete in the 2WD class again :)

I hope to drive it next season next to my TRF201 at a club, and hopefully I can even enter the FWD in a 2WD race or championship if it's not at a high level.

By the way, small update:

http://i65.photobucket.com/albums/h212/Varockshade/RSnl%20Forum%20-%20Overige/Screenshot2LowQuality.jpg

I changed the front suspension a bit: I decided to use DB01 suspension blocks at the rear. The reason is that I don't want the toe-out that the suspension arms get by using the TRF201 suspension blocks. Plus, it might give me extra space to move the steering rack further forward. I also made blanks for a low profile (Savox 1251MG geometry) servo and a stick pack (Team Orion 2S 4600mAh 45C LiPo) to explore the potential layouts for the chassis.

The current one I got pictured is what I have in mind. It won't deliver the greatest front weight balance, but it does allow me to move the battery backwards all the way to the rear suspension block if I need to. Plus, if it's necessary I can place under servo weights on the car :) I plan to use the steering rack fro a TLR 22 if they are durable enough (I got a thread about that in the Losi section) as they are so compact and simple.

Another thing I did was completing the structure of the gearbox. I hope it's accurate enough as it was hard to get good measurements on the critical mounting holes with some calipers and a set square. But after all it's much cheaper than having it run through a 3D scanner at a company for 100+ euros :lol:

Some thoughts for you, a TLR 22 steering rack will be ideal, they're very durable and compact.
Second I would use saddle packs side by side behind the steering servo to get the weight foward, seeing as i think getting traction will be the biggest issue.
Third, how about cutting the 'rear' suspension block in half and turning the halves 90deg to give trailing arm rear suspension, it's seems to be the most popular layout so why not copy it?
Finally why not use the durango 210 gearbox so you can try both 3 and 4 gear layouts to see which gives the better traction?

Rebelrc

25-11-2011, 09:34 PM

Origineelreclamebord

25-11-2011, 11:13 PM

Have you thought about turning the front wishbones around so that the car has less front overhang and will move the motor closer to the axle centre? Then shorten the rear wheel base accordingly to keep the same wheelbase as you originally planed?
Nice project though
Nice drawings

Thanks :) You're right about the front arms, they are altogether quite a crucial thing on the car. There are several problems using the stock TRF arms (TRF201 or TRF511):

1. The width of the car becomes too great (+/- 260mm, 250mm is often the legal max?)
2. The driveshafts become too short (by about 5-7mm each side - what a coincidence :p)
3. There's not enough space for the steering to move on the arms (when not using TRF511 front arms)
4. There's not a lot of space for the dampers.

I thought about this issue before and back then it resulted in me postponing the project: My conclusion was I needed too complicated a construction to make for myself: Things like inboard suspension (and using cantilevers, as the rods take in no space at all), lengthening the driveshafts or making custom shorter arms.

Things have changed though, I have access to many cool tools and awesome machines at school, making things possible that I could only ever dream of before :thumbsup:

I thought about it a bit and by far the easiest way to solve things right now would be making custom front arms. It has one major drawback, namely that there will be custom parts used in a place that are normally the parts you most likely carry as spares. The arms need to be tough, so two materials came to mind for me: Polycarbonate and Delrin. I hope I can make the arms in the laser cutter or can machine them, though if it needs be there are plenty of tools to make them by hand. Anyway, here is the revised design:

http://i65.photobucket.com/albums/h212/Varockshade/RSnl%20Forum%20-%20Overige/Screenshot3LowQuality.jpg

It's got the shorter front arms, which will get the dampers fitted at the front of the suspension arm - at least, that's the plan. There's little room to mount them diagonally, but I'll have to accept that for now with all the other existing parts I'm using. If it's too tight I might still switch to a system with cantilevers - I really like the idea and looks of it, but I want to get this beast built asap so I have a car to test - not to mention that if it's as conventional as possible existing setup knowledge can be applied to the car :lol:

Some thoughts for you, a TLR 22 steering rack will be ideal, they're very durable and compact.
Second I would use saddle packs side by side behind the steering servo to get the weight foward, seeing as i think getting traction will be the biggest issue.
Third, how about cutting the 'rear' suspension block in half and turning the halves 90deg to give trailing arm rear suspension, it's seems to be the most popular layout so why not copy it?
Finally why not use the durango 210 gearbox so you can try both 3 and 4 gear layouts to see which gives the better traction?

Thanks for the info, I guess it's a TLR22 steering rack then that I'll order this weekend for it! The 210 gearbox and saddle pack would be nice, but money is the issue here: I can't start two spares bulks, one for my TRF201 and one for an FWD car that shares no parts with it at all ;) Same goes for the saddle pack: If I'd use a saddle pack in my TRF201, then so I could on this chassis. With the knowledge I hope to gather from driving this car (and perhaps letting experienced drivers try it too) the aim is to build an FWD buggy as radical as the DEX210 is amongst the RWD buggies.

I really love the look and 'radicalness' of the trailing arms on the FWD buggies, but the same problems occur here as I wrote down above. However, your mention on just splitting the suspension block is a really nice idea, it could solve that problem. I'll definetely have a look into it :) Last spring I did a study on the geometry of the Yokomo YR-F2's suspension system if it were to be made for a buggy:

http://i65.photobucket.com/albums/h212/Varockshade/RSnl%20Forum%20-%20Overige/Screenshot4LowQuality.jpg

I was surprised by it's capabilities to create a negative camber on the outside wheel with chassis roll. It's really cool to see how the roll of the car influences the camber whereas an equal compression on both corners does not change the camber at all.

mrspeedy

26-11-2011, 12:12 AM

Origineelreclamebord

03-12-2011, 08:38 AM

Depending on what surface you intend to run on, but I would have thought traction would be your biggest priority with a FWD chassis. Big motor over hang will help here, as will a motor that spins in the opposite direction to the wheels and a good rear ward driveshaft sweep to minimise weight transfer under acceleration ....

Nice looking CAD pics btw ... looking forward to seeing this one progress :thumbsup:

Thanks for the advice. A big motor overhang will help for the balance but may also become a problem when landing with the nose too far down :lol: it's definetely something I'll have a look at though.

I'm just wondering how the rearward sweeping driveshafts minimise weight transfer? :confused: I'm quite a novice on car physics and logic gets the rough picture quite well, just eager to get more knowledgeable here.

Anyway, I have an 'update' on the project - one that's bad news and good news at the same time.

I was planning to use a laser cutter to cut out most if not all custom parts. However, the laser cutter at school:

A) Has had some reliability problems recently (needed two cycles to cut through material where it shouldn't, so it's lacking power)
B) It hasn't got the power to cut through 8-10mm PC or POM, only PMMA.

It's a big setback for the easy and quick building of this prototype. It means I have to divert to the option 'CNC machine' to make the parts! :woot: This requires me to learn to work in new software to program the paths for the CNC machine once I made the models, and I have to keep in mind the smallest bits they use are 3mm. However, it does allow me enormous freedom in the size, shape and thickness of the parts. I'm no longer thinking in 'plates', I can make blocks with odd shapes now. In theory I could now machine a tub for this car :lol: I'll keep things simple, though I am very appealed by the idea of making sidepods and mounting blocks.

PS: Have a look at this (http://www.youtube.com/watch?v=ktUeoxPauic&feature=related) :) Oh, and turn off the sound, the music is quite horrible imo. What a contraption, it seems to change the geometry/placement of the front dampers when turning, and it has 4WS! I'd love to see it in action!\

Edit:

I had a look something today which will define it's final looks: The body. To emphasize the weight and drive on the front, a front cab seems fitting - or at least not a rear cab and rear sidepods. It's hard to find, especially as I don't like the bulky and square looking Proline and Jconcepts shells.

Anyway, I have a few contenders/bodies in mind that may work for the looks and chassis layout I have in mind:

- Team Azarashi Gomurph (http://www.oople.com/rc/photos/reviewazarashizx5/) (Simple, seems easy to mod due to the simple shape, has an undertray available for it so my chassis doesn't need to seal off the underside)
- Team Azarashi Xeneiga (http://www.team-azarashi.com/zenyyga/DSCF0509.jpg) (DF03 chassis is nice and narrow, and this is a nice cab-forward-like shell)
- Tamiya DF03 body (Simply because the shape of the shell fits well what I'm looking for with my chassis layout)
- Jconcepts B44 Illuzion Scoopless body (http://www.rc-area.co.uk/blog/wp-content/uploads/2008/07/jconcepts-illuzion-b44-scoopless-body2.jpg) (I might be able to turn it 180 degrees to make it a forward cab shell and paint the windows differently)
- Tamiya Dirt Thrasher (pictured in first post. I think it looks so good it's almost sexy :p However, you can easily see how it will not cover the chassis at all without mods)
- Tamiya Avante (http://tamiyaclub.com/getuserimage.asp?t=&id=img26773_13052011013636_3.jpg) (It is a nice body, but I would have to make my own undercowl: The standard one wouldn't be practical)
- Tamiya Vanquish (http://tamiyaclub.com/getuserimage.asp?t=&id=img14438_11022007074845_6.jpg) (If I can get a repro, also a very nice body. Same story again though with 'sealing off' the body)

Any more suggestions are very welcome. I want to define my choice of body early on so the chassis and body fit each other as good as possible.

PS No.2: I'd love to make my own body, but I recall the vacuum forming machine at my school is too small for an RC body. If someone knows someone who can help me out with that, it would give my project a completely new direction.

Battle_axe

03-12-2011, 07:18 PM

Thanks for the advice. A big motor overhang will help for the balance but may also become a problem when landing with the nose too far down :lol: it's definetely something I'll have a look at though.

I'm just wondering how the rearward sweeping driveshafts minimise weight transfer? :confused: I'm quite a novice on car physics and logic gets the rough picture quite well, just eager to get more knowledgeable here.

Anyway, I have an 'update' on the project - one that's bad news and good news at the same time.

I was planning to use a laser cutter to cut out most if not all custom parts. However, the laser cutter at school:

A) Has had some reliability problems recently (needed two cycles to cut through material where it shouldn't, so it's lacking power)
B) It hasn't got the power to cut through 8-10mm PC or POM, only PMMA.

It's a big setback for the easy and quick building of this prototype. It means I have to divert to the option 'CNC machine' to make the parts! :woot: This requires me to learn to work in new software to program the paths for the CNC machine once I made the models, and I have to keep in mind the smallest bits they use are 3mm. However, it does allow me enormous freedom in the size, shape and thickness of the parts. I'm no longer thinking in 'plates', I can make blocks with odd shapes now. In theory I could now machine a tub for this car :lol: I'll keep things simple, though I am very appealed by the idea of making sidepods and mounting blocks.

PS: Have a look at this (http://www.youtube.com/watch?v=ktUeoxPauic&feature=related) :) Oh, and turn off the sound, the music is quite horrible imo. What a contraption, it seems to change the geometry/placement of the front dampers when turning, and it has 4WS! I'd love to see it in action!\

Edit:

I had a look something today which will define it's final looks: The body. To emphasize the weight and drive on the front, a front cab seems fitting - or at least not a rear cab and rear sidepods. It's hard to find, especially as I don't like the bulky and square looking Proline and Jconcepts shells.

Anyway, I have a few contenders/bodies in mind that may work for the looks and chassis layout I have in mind:

- Team Azarashi Gomurph (http://www.oople.com/rc/photos/reviewazarashizx5/) (Simple, seems easy to mod due to the simple shape, has an undertray available for it so my chassis doesn't need to seal off the underside)
- Team Azarashi Xeneiga (http://www.team-azarashi.com/zenyyga/DSCF0509.jpg) (DF03 chassis is nice and narrow, and this is a nice cab-forward-like shell)
- Tamiya DF03 body (Simply because the shape of the shell fits well what I'm looking for with my chassis layout)
- Jconcepts B44 Illuzion Scoopless body (http://www.rc-area.co.uk/blog/wp-content/uploads/2008/07/jconcepts-illuzion-b44-scoopless-body2.jpg) (I might be able to turn it 180 degrees to make it a forward cab shell and paint the windows differently)
- Tamiya Dirt Thrasher (pictured in first post. I think it looks so good it's almost sexy :p However, you can easily see how it will not cover the chassis at all without mods)
- Tamiya Avante (http://tamiyaclub.com/getuserimage.asp?t=&id=img26773_13052011013636_3.jpg) (It is a nice body, but I would have to make my own undercowl: The standard one wouldn't be practical)
- Tamiya Vanquish (http://tamiyaclub.com/getuserimage.asp?t=&id=img14438_11022007074845_6.jpg) (If I can get a repro, also a very nice body. Same story again though with 'sealing off' the body)

Any more suggestions are very welcome. I want to define my choice of body early on so the chassis and body fit each other as good as possible.

PS No.2: I'd love to make my own body, but I recall the vacuum forming machine at my school is too small for an RC body. If someone knows someone who can help me out with that, it would give my project a completely new direction.

if i can help at all with this awesome looking project i will be glad to help i have good cad skills (but so do you) i also own a small cnc mill so if you need anybits making let me know :thumbsup:

Origineelreclamebord

04-12-2011, 08:19 AM

if i can help at all with this awesome looking project i will be glad to help i have good cad skills (but so do you) i also own a small cnc mill so if you need anybits making let me know :thumbsup:

Cool, thanks for the offer! :) I need loads of bits made actually, even though I try to use as many existing parts as possible! At school we have a CNC machine: The smallest bits are 3mm, which is not a problem but I must keep that in mind when designing. The problem currently is that I don't have a working piece of software to program the paths for the CNC machine (something like Mastercam) and have never worked with it either.

Anyway, time for an update:
http://i65.photobucket.com/albums/h212/Varockshade/RSnl%20Forum%20-%20Overige/Screenshot5.jpg

http://i65.photobucket.com/albums/h212/Varockshade/RSnl%20Forum%20-%20Overige/Screenshot6.jpg

http://i65.photobucket.com/albums/h212/Varockshade/RSnl%20Forum%20-%20Overige/Screenshot7.jpg

A couple of changes have been made, all at the front suspension really. I tried to fit the lot together, and what do you know? It fits! :thumbsup: But only just as you can see in the pictures above. I can't really use several holes in the suspension arm for adjustment because of the lack of room, and at the top I might be able to use two or three holes from side to side.

For considerations of weight balance and room for the damper I decided to shape the suspension arm like I did before: Slightly swept back. The hinges of left and rihgt are still parallel though.

I'd still love to have an inboard suspension system on it, so I might have a look at it later on. For now though I at least have a front suspension system that will work.

There were some suggestions for a trailing arm kind of system. As cool as I think they are, I'm still going for double wishbone suspension. It's a system I'm more familiar with, so it will be easier for me to set up right. It will guarantee the strength of the rear suspension as well, as the rear suspension will still get the same loads and from the same directions as it was developed for.

Another FF Buggy video for you :) It is Grahoo's Poprod that was mentioned earlier in this thread, in action! It doesn't have a massive motor in it and it isn't a demanding track on your average buggy it seems, but with a TA03 transmission at the front (lightweight, no slipper) and NiMh in the middle (heavy) this car seems to do well in terms of weight balance?
http://www.youtube.com/watch?v=QRgBdysVdjI

And this one (Nichimo FF) shows why I didn't choose for a mid motor :)
http://www.youtube.com/watch?v=JLzkkbTIltA&feature=related

mof

04-12-2011, 09:00 AM

As a side note, ifmar rules for electric buggy world championships put fwd cars in the same class with 4wds, not 2wds. Even though fwds are 2wd...

Origineelreclamebord

04-12-2011, 02:10 PM

As a side note, ifmar rules for electric buggy world championships put fwd cars in the same class with 4wds, not 2wds. Even though fwds are 2wd...

I know :( They should change that though, it's an old and outdated rule (not just from the IFMAR) and was put into life to make sure drivers didn't buy a RWD and built a FWD and use one that best suited the track. They however could easily have solved this by stating people should choose their chassis for a whole season, or in case of the FWDs before the track was anounced.

Ant

04-12-2011, 03:49 PM

Is that different from being able to choose if your rwd car is mid or rear motored depending on the track?

Origineelreclamebord

05-12-2011, 06:30 AM

Is that different from being able to choose if your rwd car is mid or rear motored depending on the track?

Recently there have been released some chassis' that allow mid motor and rear motor options on the same car, and I think in the long haul, more brands may follow (despite what I'm stating below).

Plus, I read here on oOple (first page of this topic (http://www.oople.com/forums/showthread.php?t=11219)) that the IFMAR only runs on 'natural' surfaces - so I guess mid motor cars are not a popular choice for IFMAR races anyway - no astroturf, no carpet and no other high grip surfaces a mid motor chassis has the edge over a rear motor chassis.

Origineelreclamebord

18-12-2011, 11:44 PM

Time for another update :)

http://i65.photobucket.com/albums/h212/Varockshade/RSnl%20Forum%20-%20Overige/Screenshot8.jpg
http://i65.photobucket.com/albums/h212/Varockshade/RSnl%20Forum%20-%20Overige/Screenshot9.jpg
http://i65.photobucket.com/albums/h212/Varockshade/RSnl%20Forum%20-%20Overige/Screenshot10.jpg

First off, the body choice:
DEX410 body and Bugle 410 undertray, but hopefully in the long term a custom (extra) front cab body based off the chassis dimensions/curvature of the DEX410.

The second thing, the steering:
The TLR22 steering has arrived, I really like how simple and beefy it is. I measured it and though I can't make the front assembly as compact as I hoped, it does seem to get me the right geometry.

And some progress on the chassis plates:
I made a start on the design of the chassis plates. There is an upper chassis plate, to which two braces mount that reinforce the shock tower. The steering also mounts to this chassis plate. Then lastly, at the rear ends of this upper chassis plate, there will be two posts. These two posts are to reinforce the structure and the battery plate will also mount to these points. The battery plate will run over the battery to a rear upper plate. By changing the battery plate's amount of material or the material itself I can hopefully adjust flex in the chassis if needed.

As I think it's necessary to have an adjustable wheelbase on this car, I am considering to split the lower chassis plate in two pieces as well. Either that, or I need to make many mounting holes at the back for the bulkhead.

And last but not least, a bit of re-designing:
The feature is not yet visible on the pictures, but I've added it to a newer version: The rear suspension blocks of the front end will not be mounted straight to the lower suspension plate to prevent potential damage to some expensive custom parts (front suspension arms, lower chassis plate). The two blocks will be mounted to a small plate, which is then mounted to the lower chassis plate. By deliberately making it the weakest link in the construction I can prevent the expensive parts from breaking (as 'regularly' as they usually would).

Origineelreclamebord

21-12-2011, 09:53 PM

I'm currently working on the rear suspension and I got a question to ask you guys.

For the rear I'm using the front suspension arms and, hubs and uprights of the TRF201. I'll use the turnbuckles that normally are for the steering to set up the rear toe angle.

I could use the front suspension as intended, but it puts the turnbuckles of the steering exposed to impacts on the rear of the car. I'd like to turn the uprights around to get the turnbuckles in front of the axles. However, this also puts the rear axle in front of it's steering/pivoting point.

Normally this would cause bad handling, but I was wondering if this also applies when the rear wheels don't steer (apart from perhaps a tiny bit of bump steer)? :confused:

http://i65.photobucket.com/albums/h212/Varockshade/RSnl%20Forum%20-%20Overige/Screenshot11.jpg
Here's a picture of what I mean...

Bugle

22-12-2011, 05:12 AM

Origineelreclamebord

22-12-2011, 06:34 AM

Any slop in the ball joints and that will cause some bad rear end wobbling and it's pretty much impossible to eliminate all slop. Much better to have the axles trailing.
Could grab a sheet of Kydex and make a decent rear bumper?

Thanks for the advice :) It's a pity I can't make it like I had it in mind then: I was hoping I could put the shock tower in front of the shocks, so the plate would be just in front of the rear suspension arms. (a lot like the RB5's front end, but then on the rear of my car). You'd end up with the weight slightly less to the back, and a very low construction between the suspension arms itself (and to be honest, I'd do that just to make it look cool :lol: ). I can still do this, but I need to make a second, smaller plate for the toe turnbuckles if I do that.

A bumper may indeed be a good idea. I can also go for the option of constructing the rear end in a way that the shock tower will absorb most of the forces when it's hit on the rear end: A bit like the front end of the B44 and the Yokomo YZ-10 (which by the way looks very good as well imo)...

Gayo

22-12-2011, 09:39 AM

Origineelreclamebord

22-12-2011, 07:58 PM

I don't know if it is available for the 201, but AE sells inline steering hubs that you could use to get the toe-in turnbuckles inboard.

Really cool project BTW, makes me want to build one :thumbsup::drool:

Thanks for the compliments and info :) There's no such part for the TRF201, but it does inspire me to make it myself :lol:

BloodClod

28-12-2011, 05:26 PM

Origineelreclamebord

29-12-2011, 10:44 AM

Awesome looking project so far! I'm really interested to see how it turns out.

Will you be running this on astro or dirt?

I've found that on dirt wheelspin / forward traction is the main challenge to overcome. I can't wait to see how your design runs - we certainly could use more FF buggies running to test and refine designs.

I modded a FF-03 into a buggy and it had a battery layout similar to yours but on the dirt where I run the car really struggled for forward traction.

I just haven't gotten round to it but I've gotten all the parts needed to install a gear diff in my original FF (dubbed YKP locally)... plan is to put really hard oil in there to reduce the loss of any power especially on rutted areas of a dirt track.

Good luck, I'll be following this thread with interest!

Nice to get some info on the FF03 Buggy you made! I saw it on your Blogspot - and I also saw your RB5 (gearbox) based FF buggy which looks absolutely awesome :) Did you manage to keep the last one under 250mm wide at the front? I couldn't find a way to do that with the DB-01 arms, hence I chose for the custom front arms.

As for the terrain and weight distribution... I don't have a track that I usually go to (yet), though my preference goes to a natural surface (dirt, clay). Like I mentioned before, I want a narrow chassis and unfortunately I don't have saddle packs, so I'll need to play with under servo etc. weights if the the front traction is bad. It's good to know about it though, perhaps I can design the car to accept shorty LiPos and/or saddle packs as well in the future without the need for new parts :)

mark christopher

29-12-2011, 10:54 AM

Your going to need more work at the front or rear of original, no kick up no caster and toe out on arms

Origineelreclamebord

29-12-2011, 05:43 PM

Your going to need more work at the front or rear of original, no kick up no master and toe out on arms

Could I ask you what you exactly mean? :confused: Do you mean there is no kick up and it needs some, that it has toe-out and must be removed or needs it and doesn't have it yet, etc? :)

Edit 30-12-2011:

http://i65.photobucket.com/albums/h212/Varockshade/RSnl%20Forum%20-%20Overige/Screenshot12.jpg

This is a new plan for the chassis layout. That, or with the servo next to the battery. The plan is to build a (partially) custom steering set which allows me to run the steering rack over the battery. Reason for this is the advice I got several times to put the weight further forward, and the TLR22 steering rack may not give me the desired steering geometry (so I need a different system anyway).

The chassis plate as you may noticed is also split between a main plate and rear plate. I want to make the wheelbase adjustable, and with the system I can hopefully also adjust the chassis flex (by using further forward or rearward mounting points between the two plates, or using a diff/slipper spring in the mounting points of the rear plates).

mark christopher

30-12-2011, 12:29 PM

Origineelreclamebord

30-12-2011, 12:46 PM

unless your redoing the arm mounts the kick up inboard toe in will now be toe out, your also going to need to run the motor in reverse, not the best way to get good performance from a sensored system.

Thanks for the advice :) I already had the 'toe-out' effect neutralized by using the small DB01 front suspension blocks, which can be mounted any given length apart. I thought it would be good to make the suspension shafts parallel to each other.

As for the motor, I was completely unaware that sensored systems have different performance in the opposite direction! I guess I should take a sensorless system then, it also saves some money that I can put to good use on the chassis!

mr. ed

30-12-2011, 07:24 PM

Mark, what do you mean by 'master'? I'm not familiar with that concept and curious.

o.r.b., maybe you can copy the design of many 4WD's: battery on one side and the electronics on the other. Just keep the battery a little closer to the centerline since you don't have the moter on the electronics side to help balancing the weight.

terry.sc

30-12-2011, 08:52 PM

unless your redoing the arm mounts the kick up inboard toe in will now be toe out, your also going to need to run the motor in reverse, not the best way to get good performance from a sensored system.
With steering at the front end the toe in is set at the steering block, nothing to do with the inboard setting. Caster is also set at the outer end.

As for the inboard toe out, from earlier in the thread:
I changed the front suspension a bit: I decided to use DB01 suspension blocks at the rear. The reason is that I don't want the toe-out that the suspension arms get by using the TRF201 suspension blocks.
Just because rwd buggies have a lot of front wishbone kick up doesn't mean a fwd buggy should have any, in fact it's probably a good thing to have some pro-squat by having the front wishbones leaning forwards to try and prevent the front end lifting under power.

Origineelreclamebord

01-01-2012, 03:03 PM

Update on the steering:

http://i65.photobucket.com/albums/h212/Varockshade/RSnl%20Forum%20-%20Overige/Screenshot13.jpg

http://i65.photobucket.com/albums/h212/Varockshade/RSnl%20Forum%20-%20Overige/Screenshot14.jpg

http://i65.photobucket.com/albums/h212/Varockshade/RSnl%20Forum%20-%20Overige/Screenshot15.jpg

I have replicated the TRF201 steering arms and tried to come up with a compact steering system at the front. I'm still not sure whether it will be the servo or the battery to be fitted between the steering arms, but either way the idea should work well. I hope the maximum deflection/steering lock of the DB01 uprights is enough for a tight cornering car.

The geometry is ok in terms of the Ackermann angle: At the steering lock the angle is slightly bigger than needed for the 'ideal' angle of Mr.Ackermann's theory (in which the two lines coming from the front axles cross at the axis resembling the rear wheels). I read a bigger Ackermann angle would lead to predictable, unagressive steering behaviour: Something that should suit the consistency and smooth driving style needed for driving an FF quickly. However, I also need to keep in mind that a bigger Ackermann angle may reduce the amount of steering I have.

There's a couple of issues I still need to solve:

1. Decrease the massive amount of bump steer when the outside of the suspension arm pivots below the horizontal point. (Above that point the bump steer is minimal)
2. How to build the front end around the steering geometry I developed :lol:

Honza D

02-01-2012, 11:37 PM

interesting project but.. I'm not sure about traction on slippery surface... imho FWD is good for low-power motors (as in video you've posted, 1/10th buggy with 400-size silver can).. But with stronger motor it will have lot of wheel spin and no acceleration because of weight transfer towards to rear-end of car.. That's why I'm trying opposite project in RC rallying (there're lot of FWDs - based on Tamiyas FF-s or M-s - and no RWDs because there is no base onroad RWD with IRS), because FWDs has poor acceleration and have problems with jumps and hill climbing.. but RWD handling is much better, closer to 4WDs.. I think that buggy wil be very similar = good for high traction - low power, but not for low traction or high power conditions.

mr. ed

18-04-2012, 01:08 PM

any update?

Origineelreclamebord

18-04-2012, 05:22 PM

any update?

Unfortunately not :( I haven't had time for the project the last few months, which is a shame, as I was hoping I would've finished building it by now. I have been thinking about the project a lot though. I think I am going to ditch the front shock tower design and go for inboard suspension - it's something I wanted to do from the beginning but thought making it would be complicated. However, it makes a lot of room at the front and it would be cool to try something 'new.'

Pablo668

20-04-2012, 01:22 AM

Did you draw up those 201 components yourself?

I'm looking to do some drawings in solidworks using 201 components.

Origineelreclamebord

20-04-2012, 06:27 AM

Did you draw up those 201 components yourself?

I'm looking to do some drawings in solidworks using 201 components.

Jup, I tried to make them as accurate as possible using just calipers. The gearbox is just a solid block as I didn't need to measure the guts for this project, it was a pain to get it accurately (measuring, re-measuring, modeling, re-re-measuring... :lol:)

Anyway, if you are interested in the components, just drop me a PM.

Pablo668

20-04-2012, 03:17 PM

Jup, I tried to make them as accurate as possible using just calipers. The gearbox is just a solid block as I didn't need to measure the guts for this project, it was a pain to get it accurately (measuring, re-measuring, modeling, re-re-measuring... :lol:)

Anyway, if you are interested in the components, just drop me a PM.

Great job, pm sent.

mbeaney

24-04-2012, 11:11 AM

Great job on the design,
Not sure if this is the best place to ask but I am looking to do some design work in Solidworks on my B4.1 and was wondering if anyone has and components modelled that I could have as a start point.

Regards

Mark

isobarik

24-04-2012, 12:00 PM

Origineelreclamebord

25-04-2012, 08:33 AM

I just wonder what the will you do when get to the table top ?????
i dont think it will run/jump well.

Think like this if it would work someone should have done it alot sooner ...

but hey dont loose that faith ...

mvh Isobarik

The thing is, they have been built before, and it works :) Most of them were custom projects. The only reason pretty much no-one has one or knows about the existance of these cars is the fact that RC racing organizations banned the FWD buggies from the 2WD class and put them in the 4WD class, because they wanted to prevent people from having an unfair advantage by driving a rear wheel drive car on high bite tracks and front wheel drive cars on low bite/slippery tracks.

And at the end of the day, if it jumps bad, it will be my task to keep on looking for solutions to make it jump well and keep enough forward traction! :p For example, on jumps (thus at high speeds), high rear downforce might help the car keep level-ish in the air, whilst at low speeds the weight on the front (and the low downforce due to the low speed) will give the car sufficient traction on it's driven wheels.

Pablo668

25-04-2012, 01:37 PM

Origineelreclamebord

26-04-2012, 05:44 AM

Erm, it may have been mentioned in this thread already, but there is another thread in here by a member called Bloodclod I think.
He made an awesome FWD buggy based on ones that were factory made back in.....the late 80's maybe?

So they have been done and they worked ok, design problems notwithstanding.

eta: as a matter of fact, here it is. Well worth a look see.

http://www.oople.com/forums/showthread.php?t=44869&highlight=Bloodclod

He had a blog and a video footage of it running on youtube, but sadly he removed that. It's good to see his threads (with pictures) still exist on oOple and RC10Talk. When my buggy is finished I hope to change that though, there should be some more documentation of these cars out there!

Origineelreclamebord

28-04-2012, 09:54 AM

I thought I'd show you guys the first update since... ages! :lol:

http://i65.photobucket.com/albums/h212/Varockshade/FWD%20Buggy%20Project/Screenshot16.jpg

I made a mockup on the inboard suspension and body. This layout gives it's own problems, this time not around the gear cover, but around the steering rack and rocker arms. There's not a lot of space to put everything, so I have to re-arrange some parts.

However, it looks promising to me. I just need to calculate what geometry I need to make maximum use of the potential displacement of the shocks but also keep track of whether there are springs, pistons and oils to make a good setup at that geometry.

Edit:

After working on the project for an afternoon, this is the result:

http://i65.photobucket.com/albums/h212/Varockshade/FWD%20Buggy%20Project/Screenshot17.jpg

As you might have noticed, the rocker isn't as low and elegantly placed as it first was. But to be fair, that was a long shot. The problem is that the tie rods and the rocker arms 'ideal' position is in the same place. Something told me that might not work in practice :lol:

I tried moving the tie rods, but there is little room for changes without making the steering geometry kind of knackered. I also looked at moving the rocker arms, preferably forward, but there is no room for that due to the spur gear, motor plate and gear cover. So whatever I tried, the suspension ended up higher.

In the end, this is about the lowest I could get it to be. The problem only existed when cornering with the inside wheel pushed up - it's not likely to happen, but I thought it would be best not to limit the suspension's movement by having parts binding. As you can see here below, there is now plenty of clearance between the grey rocker arm and the orange adjuster of the tie rod.
http://i65.photobucket.com/albums/h212/Varockshade/FWD%20Buggy%20Project/Screenshot22.jpg

I really like the result of removing the shock tower: It allows for more freedom in setup: There can now be 3 holes for mounting the suspension in the lower arm instead of one, and I can adjust the suspension drastically by using different rocker arms. The weight is further to the middle and I think the centre of gravity won't be affected much in terms of height. And last but not least, look at this front profile! :wub
http://i65.photobucket.com/albums/h212/Varockshade/FWD%20Buggy%20Project/Screenshot18.jpg

While working on the inboard system I realized I needed to adjust the arrangement of the electronics on the chassis - once again! To accomplish the arrangement below I need a custom top arm on the servo saver, because the standard 201 arm is in line with the lower arm of the servo saver, not perpendicular to it. Unfortunately, the large space between the gearbox and battery is necessary to make the steering rack. However, it does leave some space for weights low in the front of the car, which is nice.
http://i65.photobucket.com/albums/h212/Varockshade/FWD%20Buggy%20Project/Screenshot19.jpg
http://i65.photobucket.com/albums/h212/Varockshade/FWD%20Buggy%20Project/Screenshot21.jpg

The rear end won't have an inboard suspension system. I've looked at it, but if anything, it makes it more difficult to take the battery out and it doesn't lower the centre of gravity. Using the rocker arms actually made the rear suspension system higher than the shocks when placed at 45 degrees, which they are now. I hope I can use the shocks angled so far down so I can keep a low profile on the whole car. The wing will be mounted low to the small rear shock tower, and there will be a seperate mounting block or plate for the rear turnbuckles and rear tie rods behind that.
http://i65.photobucket.com/albums/h212/Varockshade/FWD%20Buggy%20Project/Screenshot20.jpg

Today has been a day of some drastic re-thinking of this project. First of all, I have some experience in 3D printing nowadays, and I will use this production method for some of the parts, and probably many mockup/first test parts. Secondly, I reconsidered the whole design of an FF Buggy. I even drew up some sketches of an inboard motor FWD buggy with the steering rack and servo on the front, with room for chassis weights to make a good balance. It sounded nice, as if it would solve the problems with finding space for all the parts, but I thought that the space at the front wouldn't be a problem with a compact TRF201 gearbox instead of a Dyna Storm gearbox when I started this project. The only thing the 201 gearbox did is raise the stakes and make the project possible, but not problem-free or easy :p

I'm happy with what I got done today though: The mockup seems to have no issues, so I am now confident enough about how the parts fit together to start modeling all the parts for the inboard suspension.

Spoolio

28-04-2012, 11:43 PM

Could you adapt the Tamiya FF03 bits for your project, that uses a 201 'box and inboard rocker suspension too? Or maybe the new XV-01 (chassis drawing on Tamiyablog.com).

Origineelreclamebord

29-04-2012, 07:00 AM

Could you adapt the Tamiya FF03 bits for your project, that uses a 201 'box and inboard rocker suspension too? Or maybe the new XV-01 (chassis drawing on Tamiyablog.com).

Thanks for the advice :) I've already seen an FF03 converted to a buggy (Click (http://ffbuggy.blogspot.com/)), and I've did a similar conversion with an FF01: Just using DF01 suspension arms and tub. It drove quite well, but I was looking for something more competitive and serious.

Competitive = competition car. I wanted a slipper clutch gearbox, so then you quickly end up in the buggy scene. Since I had a TRF201 already, it was almost a no-brainer to get a 201 as a donor car for this project - more spares for my 201, and I don't have to buy two spares bulks for the two cars! :thumbsup:

The XV-01 is indeed a promising alternative, but I'm already too deep into the 201 based design to go back.

If I'd really go berserk on this car, I would design my own suspension system from the ground up, driveshafts, gearbox (which would be radically different and would not need a slipper) and chassis parts that have a shape that searches the limits of production techniques - which means I'd also be looking at 3D printed parts for the final car (something I do now as well, but probably not using the freedom of shape on those parts to the max). However, for that I lack money, knowledge and experience. This project is to get a start on that. Develop it, build it, test it, let others test it (a most crucial step to find out how well the car handles and to find areas for improvement) and do the process all over again in the future.

OldTimer

29-04-2012, 09:10 AM

Remember you need to add the front camber links, these always seem to get in the way :)

Origineelreclamebord

29-04-2012, 10:36 AM

Remember you need to add the front camber links, these always seem to get in the way :)

Hehe thanks for the tip! I removed them to reduce the chance of errors in SolidWorks: It seems SolidWorks just can't seem to understand ball joints and concentric mates very well if you have a lot of them. Apparently removing the front links wasn't enough, as it doesn't listen to any of the concentric mates I set anymore: The ball connectors don't stay in their adjusters anymore whilst it did work yesterday. Ah well, time to re-assemble the low - again :thumbdown:

Anyway, to come back to your point: I checked yesterday if the upper links would fit. They need to move to the front a bit, but it will fit. It's almost too tight for comfort, but it will have to do :lol: The DEX210's inner rear adjusters may help to create a little more room by the way.

Origineelreclamebord

01-05-2012, 08:07 AM

Update time:

http://i65.photobucket.com/albums/h212/Varockshade/FWD%20Buggy%20Project/Screenshot23.jpg

http://i65.photobucket.com/albums/h212/Varockshade/FWD%20Buggy%20Project/Screenshot24.jpg

http://i65.photobucket.com/albums/h212/Varockshade/FWD%20Buggy%20Project/Screenshot25.jpg

I made a top plate in the front. This has several functions:

- Hold the servo in place
- Hold the battery in place
- Mount for the dampers (through the small mounting block)
- Still to do: The block to which the rocker arms will also be partially mounted to the top plate.

I also made the inner mounting positions for the upper links on the front of the car. I don't yet have pictures of it, but in the mockup it worked well :thumbsup:

I've replaced the rear suspension block (which was a TRF201 front suspension block) for DB01 suspension blocks on 4 corners, connected to plates. This makes for more adjustability, and they are easier to mount: I noticed on my 201 that the blocks themselves very much depend on the L10? part (front top frame/mount for front shock tower) to stay in place - the holes don't have threads and are at least 3mm, so mounting it firmly into place needs a very specific construction and part - something I didn't really want as this works for me too!

And last but not least, I have been working on the wheelbase adjustability on the rear. It needed to be compact so I can still take the battery out, and to save weight. My thought was that I could slide two small plates over each other, which makes for a compact construction and strengthens the narrow plate constructions in the rear.

almunro

01-05-2012, 11:04 AM

i know you want the weight over the front wheels to gain traction, but surely you will need to move the battery more towards the rear so it doesnt nosedive off jumps?

Origineelreclamebord

01-05-2012, 02:55 PM

i know you want the weight over the front wheels to gain traction, but surely you will need to move the battery more towards the rear so it doesnt nosedive off jumps?

I understand your problem, and sure in a configuration like this there are compromises to both forward traction and the 'ideal' weight balance for cornering and/or jumping.

However, if people manage to make their cars backflip through the air and land on 4 wheels by adjusting their throttle with a car with the weight slightly to the rear, then I think it can too be done with the weight up front, even if it's only 2WD. I managed to make my TRF201 land almost vertically (both nose first and motor first) on the jumps of an average 1/10th scale track. Why wouldn't the car be able to do the same going backwards? :)

I've seen video footage of BloodClod's FF buggy and Grahoo's (TamiyaClub member) FF buggy, and both seemed to manage the jumps pretty decently (even if the jumps Grahoo's buggy made were pretty small).

And if physics somehow don't at all work in reverse, then I know it's time to get a bit more creative on the design: Perhaps a system that changes the weight balance during acceleration or on command of a switch will be the answer to the problem, a gyroscope, black magic? :lol:

almunro

01-05-2012, 03:03 PM

Double post, sorry. slow oople today.

almunro

01-05-2012, 03:04 PM

You might be right but a car that requires a lot of throttle control to fly and land properly is a pain in the backside to drive. Thats one of the reasons mid-motor is so popular is because they jump nice and level. It will be interesting to see when you get this going.

Maybe adding the ability to slide the battery forward and back will be a good thing to have during initial testing.

terry.sc

01-05-2012, 11:57 PM

i know you want the weight over the front wheels to gain traction, but surely you will need to move the battery more towards the rear so it doesnt nosedive off jumps?
All the previous successful FWD buggies have had very little rear weight, usually even less than this design. See here for examples http://www.oople.com/forums/showthread.php?t=44869
These vintage fwds could lap Yatabe faster than Masami with his RC10.

Origineelreclamebord

02-05-2012, 08:28 PM

http://i65.photobucket.com/albums/h212/Varockshade/FWD%20Buggy%20Project/Screenshot26.jpg

Time for another update! There is only one big part left to model :woot: It's the block to which the rocker arms mount. I think I'll use TRF201 front axles or something similar as an axle for the rocker arms to rotate on - then there are some small things to model, like the mounts for the axles which the steering arms rotate on, and I got a very nice idea to add weight very low in the front of the car.

List of updates - New parts:
- Mounting block for rear suspension parts. This part mounts is a mounting block for the rear shock tower, a plate for the tie rods and a plate for the upper links of the rear suspension.
- Rear shock tower. This includes holes for the wing mounts - these will be TRF201 wing mounts. You might notice the holes are pretty low, this is down to both issues with space and the fact that I think the wing should be low :p
- Rear tie-rod plate.
- Rear upper link plate.
- Sidepods (120mm total chassis width). The sidepods replace the earlier 'wide' chassis. The vertical edges will make a better fit for bodies and better protection for the electronics. The sidepod also lifts up the edges slightly, so the chassis doesn't bottom out easily in corners. It also makes the main chassis plate cheaper.
- Battery retainer. Unlike many battery trays, this one is suitable for pretty much any stick battery, wherever the the wires exit.
- Name. Like any car this needs a name. I could have gone for outrageous names or a name ending with 'V.3.0.6.2.01 Beta' or 'Gen 5', but even though I worked on it a lot, I found peace in a much simpler name :lol: 'How about TRF201 FF?'

List of updates - Updates parts:
- Tweaked/optimized rear suspension geometry (for neutral base setup in terms of change in toe and camber throughout the suspension's movement, but with plenty of room to adjust)
- Narrower chassis plate (81mm instead of +/- 110mm). This is for several reasons. I noticed I needed an 'even' wider chassis than 110mm to fit electronics comfortably. Widening the chassis would make it more expensive and stiffer (and my prediction is that it doesn't need to be that rigid). I thought sidepods would be a suitable alternative.

http://i65.photobucket.com/albums/h212/Varockshade/FWD%20Buggy%20Project/Screenshot27.jpg
http://i65.photobucket.com/albums/h212/Varockshade/FWD%20Buggy%20Project/Screenshot28.jpg
http://i65.photobucket.com/albums/h212/Varockshade/FWD%20Buggy%20Project/Screenshot29.jpg
http://i65.photobucket.com/albums/h212/Varockshade/FWD%20Buggy%20Project/Screenshot30.jpg
http://i65.photobucket.com/albums/h212/Varockshade/FWD%20Buggy%20Project/Screenshot31.jpg
http://i65.photobucket.com/albums/h212/Varockshade/FWD%20Buggy%20Project/Screenshot32.jpg

I think I'll contact Team Xtreme for advice on the rocker arms and whether it's likely the geometry of the front suspension system allows me to use existing stiffness 1/10 buggy rear (or if it needs be front) springs and 'regular' damping setups - Or can someone else help me with this? :confused:

When all this looks allright I'll have the parts 3D printed and cut the plates in a laser cutter from plastic. It will be for mockup and a test in practice to see how the geometry runs.

IF it gets the green light on every single of these steps without major adjustments I should be able to get the plates cut from carbon and some of the parts machined from carbon reinforced plastics or metal.

You might be right but a car that requires a lot of throttle control to fly and land properly is a pain in the backside to drive. Thats one of the reasons mid-motor is so popular is because they jump nice and level. It will be interesting to see when you get this going.

Maybe adding the ability to slide the battery forward and back will be a good thing to have during initial testing.

I indeed noticed how easy the Xfactory X6 was to jump when I was offered to try it out :o

That said, one of the goals of this project is to make an FWD buggy that has the potential to go fast around a track. That, and to form a base to get data from driving FWD buggies, as there is only basic data available on what forms a good FWD chassis (such as most of the weight being in the front for forward traction).

Whether it will be competitive with the right setup and in the hands of the right driver or in the hands of every driver and with every setup is difficult to say beforehand. That's why I'm building one to find out, and to see where there is room for improvement :)

OldTimer

02-05-2012, 08:39 PM

mr. ed

02-05-2012, 08:47 PM

Origineelreclamebord

02-05-2012, 09:07 PM

I was looking at your latest pic while my attention was elsewhere , and suddenly realised how cool it would be to have that in-board damping system in the rear of a standard or even mid motered RWD buggy

In that case I think you'll absolutely love these links:

Grahoo's Hotshot (http://www.flickr.com/photos/grahoo/sets/72157614036995630/with/4171953976/)
Team Kassanova K2 (Link 1 (http://teamkassanova.webs.com/k22wdbuggy.htm), Link 2 (http://www.rctech.net/forum/electric-off-road/419143-project-team-kassanova-k2v2-2wd-buggy.html))

Origineelreclamebord

02-05-2012, 09:20 PM

I would really look at the rear end suspension having trailing arms rather the more tradional buggy arms, the cars are very light at the rear and i don't think what you are planning will be the optimum way to go. You will need very light damping / spring and from everything i have seen trailing is the way to go.

Also with the tralining arms you will also be able to lower the c of g nicely as the shocks will no long be sticking up in the arm ;) and its very simple to setup camber and toe via turnbuckles which attach via the trailing arm.

Also for us to run this car in the uk, it can be no more than 250mm wide which i think could be a issue if your using a 4wd front end with rear hubs fitted, and rear tires would have to be fitted at the back of the car for it to be legal.

Btw if you get stuck for making the plastic parts give me a shout.

Thanks for the advice, and for your heads up on the production of parts :)

Just a question: Do you think it would be a regretful decision or a mistake (performance wise) if I stick with the double wishbone suspension?

The thing is, I have nearly finished the car now. The reason I have chosen for a regular layout at the back (earlier in the project) is for the reason that I know little about setting up cars - for me it's a way to keep the conventional bit in the car and be able to talk easier with people about setups for this car. However, with the change on the front suspension I guess that's not really the case anymore for the car anyway.

As for the width: I know about the 250mm rule, it is why I have designed custom front suspension arms. I should be able to use 70mm (DF-03 length) universal shafts on the front end, though it will be a tight fit and might require the use of shortened outdrives and/or a gear diff (so I don't have a screw and spring in the outdrives in the way of the uni's).

The wide rear tire rule is a problem though - especially with the current rear suspension :lol: Even though I don't run in the UK, I was hoping the car would be 'legal', I thought getting it less than 250mm wide would have been my biggest issue with regards to the rules - besides the fact that most regulations state it must be run with the 4WDs. It's a strange rule though, why would anyone chose to fit narrower tires on the rear except for when you'd be driving an FF car?

Origineelreclamebord

03-05-2012, 06:41 PM

Update:
I have to thank Jonathan/OldTimer for notifying me of the rules of the BRCA with regard to the rear wheels/tires. It seems in the UK you are limited to using rear tires on the rear.

However, the EFRA (and the Dutch RC Sporting Organisation which bases it's chassis regulations on that of the EFRA) doesn't seem to have rules restricting the use of the rear wheels to wide ones.

Of course it may be possible to enter the car as an RWD buggy with rear wheel steering and set up to drive around the track backwards real quick :lol: However, I think it won't take long before they ban that sort of 'F1 style' of stretching regulations if you'd try that. Therefor, here's an alternative version to the car using DB01 uprights and C-hubs on the rear as well. It's my intention to build and test both types:

http://i65.photobucket.com/albums/h212/Varockshade/FWD%20Buggy%20Project/Screenshot33.jpg
http://i65.photobucket.com/albums/h212/Varockshade/FWD%20Buggy%20Project/Screenshot34.jpg
http://i65.photobucket.com/albums/h212/Varockshade/FWD%20Buggy%20Project/Screenshot35.jpg

I prefer the narrow wheel version, both for expected performance (you don't need that wide wheels on the rear I think) and aesthetics. But if this change will help it to be legal on the UK events the changes are worth it!

Alfonzo

04-05-2012, 11:52 AM

Nice work. One observation I have regards the front shock bell cranks. I wonder if the large angular change in direction coupled with the quite short lever arm might result in some unwanted high forces about the pivot point. Don't sacrifice strength here, and make sure everything is a good fit to help prevent any kind of motion 'lock out' that might occur through misalignments etc. A larger input lever arm would help perhaps.

The cranks on the Pred take quite a hammering because you have a large force leverage at that point.

Keep going, it looks interesting.

terry.sc

04-05-2012, 03:14 PM

Just a question: Do you think it would be a regretful decision or a mistake (performance wise) if I stick with the double wishbone suspension?
The double wishbone suspension is fine, it's one less variable to deal with for you. The long trailing arms used on the old cars would help reduce rear weight, but you have to get the geometry right first time or come up with some way of adjusting the wheel hub on the trailing arm. The double wishbone setup you have will be much simpler to adjust.

It's a strange rule though, why would anyone chose to fit narrower tires on the rear except for when you'd be driving an FF car?At national level races we usually have a rule that means you must use a particular tyre on the rear of the buggy, both on 2wd and 4wd classes. It's not that you have to use rear tyres on the rear, it's just to save the racers having to buy lots of tyres just in case one particular spike or compound works better than the rest on that particular day, so saving money as you know in advance what tyres to buy. If everyone uses the same tyre then there is one less variable, usually the tyre is chosen by the local racers so you can guarantee it works well. There is no limit on what tyres you fit on the front so you can choose which front tyres give the best balance for you, having only one type of rear tyre also means you only need 2-3 different front tyres to choose from, again saving money.

I think I'll contact Team Xtreme for advice on the rocker arms and whether it's likely the geometry of the front suspension system allows me to use existing stiffness 1/10 buggy rear (or if it needs be front) springs and 'regular' damping setups - Or can someone else help me with this? :confused:With rocker arms, if the shock and link mounting points on the rocker are the same distance from the pivot, the spring rate will be the same as the shock compresses the same amount as if it was mounted on the wishbone at the same angle. As your links are angled quite low, if your shocks were mounted there instead you would need stiffer springs than normal.
If your shock is mounted on the rocker at 2 times the distance from the pivot as the link mounting point, if the link rises 3mm the shock will be compressed 6mm, and you will have 2 times the spring rate pushing on the link.

The only way to be sure you have it sorted is to experiment. The X11 has machined rockers as the geometry was already developed from the original Predators, and TTech themselves didn't get it right first time which is why we had the GP rockers, which were the original plastic rockers with a carbon fibre plate on top to move the link mount to a different angle on the rocker. You can always do the same if needed, make the rocker a bit smaller and use a carbon fibre plate to attach the link or shock mounts to the rocker, so you can easily cut and drill new plates if you need to change the rocker geometry.

If you

Origineelreclamebord

07-05-2012, 08:16 AM

Thanks for the explanation :)

The part on the rocker arms is extremely helpful. It confirms what I thought about the distribution of the forces to the damper. I will definetley try out several rocker arms and types of geometry to get it to work well.

The regulations are just something I have to accept - running rear tires might now be necessary (or optimal for that matter), but on the other hand, if the project turns out to be (extremely) succesful, lighter wheels and/or inserts could be developed for it too.

The double wishbone suspension is fine, it's one less variable to deal with for you. The long trailing arms used on the old cars would help reduce rear weight, but you have to get the geometry right first time or come up with some way of adjusting the wheel hub on the trailing arm. The double wishbone setup you have will be much simpler to adjust.

At national level races we usually have a rule that means you must use a particular tyre on the rear of the buggy, both on 2wd and 4wd classes. It's not that you have to use rear tyres on the rear, it's just to save the racers having to buy lots of tyres just in case one particular spike or compound works better than the rest on that particular day, so saving money as you know in advance what tyres to buy. If everyone uses the same tyre then there is one less variable, usually the tyre is chosen by the local racers so you can guarantee it works well. There is no limit on what tyres you fit on the front so you can choose which front tyres give the best balance for you, having only one type of rear tyre also means you only need 2-3 different front tyres to choose from, again saving money.

With rocker arms, if the shock and link mounting points on the rocker are the same distance from the pivot, the spring rate will be the same as the shock compresses the same amount as if it was mounted on the wishbone at the same angle. As your links are angled quite low, if your shocks were mounted there instead you would need stiffer springs than normal.
If your shock is mounted on the rocker at 2 times the distance from the pivot as the link mounting point, if the link rises 3mm the shock will be compressed 6mm, and you will have 2 times the spring rate pushing on the link.

The only way to be sure you have it sorted is to experiment. The X11 has machined rockers as the geometry was already developed from the original Predators, and TTech themselves didn't get it right first time which is why we had the GP rockers, which were the original plastic rockers with a carbon fibre plate on top to move the link mount to a different angle on the rocker. You can always do the same if needed, make the rocker a bit smaller and use a carbon fibre plate to attach the link or shock mounts to the rocker, so you can easily cut and drill new plates if you need to change the rocker geometry.

If you

Pablo668

07-05-2012, 12:54 PM

Yeah I'm going to agree with an earlier comment.

You should definitely use the excellent work you have done so far as the basis for a standard RWD chassis as well, if only as a sideline.

The FWD idea and the work you've done is great and I hope you get it done soon and see how it goes, it's just looking at it, it would also make a sweet aftermarket RWD chassis as well with a few bits and bobs changed.

Looks a little Durango-ish, I think it's the side pods.

mro_racing aka Doorbell

09-05-2012, 04:37 PM

just been looking at your design and i understand that the inboard suspension design is better becouse of space but the idear of inboard suspension is to lower the C/G but its a compromise as the suspension doesnt work as well as the conventional way. plus does look cool :).
ive looked at where the shock absorber are on your car and plus all the extra weight to get the shock absorber to where they are and it seems to have a much higher C/G than a conventional front suspension so it seems to me that having inboard suspension in the way you have done it is to much of a compromise. also with my experience with a fwd touring car i used to race yokomo yrf2 sp and also am running atm a tamiya m05 ra and having trailing arms rather the more tradional suspension arms does work alot better.

but even though i think there are a couple of things wrong your work on the car does look sexy :)

Origineelreclamebord

21-06-2012, 04:31 PM

It's been a while since the last update due to 2 things:

1. Busy with stuff for school
2. My hard disk crashed (and became unsalvagable too), and I lost my last 4 months of work because I didn't make a backup...

...Luckily this project was one of the very few things I did have a backup of! :)

Now that I have had all my deadlines for school for 2011-2012, I can re-focus on the project.

A month of not modelling on the car gave me time to think about the comments and advice I got for the design, and I decided I wanted a couple of things changed. They are mainly with regard to the weight balance. A shorty LiPo to shift the weight balance without having to widen the chassis. Then secondly, a trailing arm system. In the new layout the only 'weighty' parts on the back half are the dampers, so the weight balance is guaranteed to give good forward traction. Jumping it will be more of a challenge probably, but I think practice will be key to success there :)

http://i65.photobucket.com/albums/h212/Varockshade/RSnl%20Forum%20-%20Overige/Screenshot40.jpg
http://i65.photobucket.com/albums/h212/Varockshade/RSnl%20Forum%20-%20Overige/Screenshot41.jpg
http://i65.photobucket.com/albums/h212/Varockshade/RSnl%20Forum%20-%20Overige/Screenshot42.jpg
http://i65.photobucket.com/albums/h212/Varockshade/RSnl%20Forum%20-%20Overige/Screenshot43.jpg
http://i65.photobucket.com/albums/h212/Varockshade/RSnl%20Forum%20-%20Overige/Screenshot44.jpg
http://i65.photobucket.com/albums/h212/Varockshade/RSnl%20Forum%20-%20Overige/Screenshot45.jpg

As you might have noticed, the first few pictures have DB01 uprights and caster blocks on the rear. However, Jonathan gave me the advice to make a one-piece arm, using slight negative camber and some toe-in. In the end 2 degrees of toe-in on each side and 2 degrees of negative camber is the setup on the rear. The rear arms have approximately 65mm articulation, which should be more than enough!

Steve.T

21-06-2012, 04:48 PM

Reminds me of the front wheel drive yokomo I used to drive on road, the yr4 f2 I think.
May I suggest a potable HD in case yours crashes again?

Origineelreclamebord

21-06-2012, 05:46 PM

Reminds me of the front wheel drive yokomo I used to drive on road, the yr4 f2 I think.
May I suggest a potable HD in case yours crashes again?

Hehe :lol: I have a portable hard drive, but I was too busy to make the backup when I remembered myself about it, and when I wasn't too busy I forgot! :thumbdown: Stupid of me to not MAKE time for it.

As for the car, I think you mean the Yokomo YR-F2?

http://img229.imageshack.us/img229/6618/yrf2special2nq9.jpg

Steve.T

22-06-2012, 06:07 PM

Yes the F2. Mine was the more basic version but I loved driving it.
I work on a IT service desk and believe me I've heard much worse.
If you ever get this project made a a going concern I'd be very keen to buy.

cjm_2008

23-06-2012, 08:09 AM

As you might have noticed, the first few pictures have DB01 uprights and caster blocks on the rear. However, Jonathan gave me the advice to make a one-piece arm, using slight negative camber and some toe-in. In the end 2 degrees of toe-in on each side and 2 degrees of negative camber is the setup on the rear. The rear arms have approximately 65mm articulation, which should be more than enough!

these pictures look awesome. I think you have a career as an automotive engineer beckoning :thumbsup:

I wish I'd tackled something like this for my CDT gcse project 18 years ago!

a couple of things you might want to consider:
1. where's the x-axis COG? at the moment it looks like there's a lot of weight forward of the front axle line - this might be best for packaging as it allows space for the steering bell crank mechanism, but it may cause excessive fore-aft weight transfer under breaking and turn in, resulting in initial understeer and snappy lift-off oversteer when the rear end quickly unloads (the front axle becomes the pivot point for the moment of inertia).

2. how about extending the main chassis plate past the trailing arm swivel blocks so standard length stick packs can be accommodated? this additional chassis material could also be used for weight mounting to pull the COG forward or backward along the centreline as desired.

but these are just suggestions - ultimately, it's looking amazing at this stage. you should be very proud indeed :thumbsup:

Chalkie

23-06-2012, 09:58 AM

That looks much better, I think it would be nice to have a easy quick way to adjust the toe in on the rear as it will be a quick way to change the balance of the car, and perhaps some more mounting points for the rear shocks to start with until you've run it a few times and know what works?

Origineelreclamebord

29-06-2012, 01:13 PM

Thanks for the great response and the advice :thumbsup:

The design work of the first prototype (to be built) is almost done now. I'm sure that if the progress is good and the chassis layout looks promising, there will be time and budget to make things like adjustable toe and camber on the rear end happen,and I'm sure the weight balance will be one of the main things on the car to be tweaked with.

If it turns out it is 'necessary' to test a stick pack LiPo, I can make a new brace for the battery :)

By the way, here is another update:

http://i65.photobucket.com/albums/h212/Varockshade/FWD%20Buggy%20Project/Screenshot46.jpg
http://i65.photobucket.com/albums/h212/Varockshade/FWD%20Buggy%20Project/Screenshot47.jpg
http://i65.photobucket.com/albums/h212/Varockshade/FWD%20Buggy%20Project/Screenshot48.jpg
http://i65.photobucket.com/albums/h212/Varockshade/FWD%20Buggy%20Project/Screenshot49.jpg

First of all, I made a new mounting system for the servo. This allows for mounting the servo lower (thus having a lower CoG), and a cheaper conversion for servos that deviate too far from the Savöx SC-1251MG's dimensions.

I also made some good progress on the steering and front suspension assembly: I made the frame pieces that hold the rocker arms and their axles, and holds the top mounts for the steering arms.

Lastly, I made a plate that connects the gearbox with this frame piece as a reinforcement to the chassis. This plate is the 'shark fin' on the car. I made it higher than the rocker arms to (hopefully) protect them in a crash.

terry.sc

29-06-2012, 02:39 PM

1. where's the x-axis COG? at the moment it looks like there's a lot of weight forward of the front axle line - this might be best for packaging as it allows space for the steering bell crank mechanism, but it may cause excessive fore-aft weight transfer under breaking and turn in, resulting in initial understeer and snappy lift-off oversteer when the rear end quickly unloads (the front axle becomes the pivot point for the moment of inertia).

There is only the motor and gearbox in front of the front axle, and this is a proven layout that has been used in previous successful fwd buggies, You can find links to them in my post on the first page of this thread. As for handling, they do require a different driving style as they never spin out. According to Blooclods FF build you coast into the corner and once turned in just power all the way through the corner.

Although Bloodclod has closed his youtube account, I have found a copy of his video of his FF in action and uploaded it here. (http://www.youtube.com/watch?v=Dx5PJJx-jAg)

cjm_2008

29-06-2012, 04:21 PM

There is only the motor and gearbox in front of the front axle, and this is a proven layout that has been used in previous successful fwd buggies, You can find links to them in my post on the first page of this thread. As for handling, they do require a different driving style as they never spin out. According to Blooclods FF build you coast into the corner and once turned in just power all the way through the corner.

Although Bloodclod has closed his youtube account, I have found a copy of his video of his FF in action and uploaded it here. (http://www.youtube.com/watch?v=Dx5PJJx-jAg)

that does look amazingly stable through the corner - and like you say, he just nails it past the apex. pretty impressive. looks like it jumps well too.

Origineelreclamebord

30-06-2012, 03:26 PM

Thanks for posting that terry.sc! :thumbsup: I have seen the video and it's good to see this footage is still out there: It's really hard to find pictures of FF buggies in general, let alone video footage!

By the way, terry, about the balance: It indeed looks good, but if you look at the footage of Grahoo's buggy (posted earlier in this topic) you'll see it appears to have a more stable rear end (weight and milder motor?) - Whether that's a good thing or not I don't know (as the oversteer may help a lot on turn in), but during testing I will sure play with adding and shifting weights to see how the car responds :)

terry.sc

01-07-2012, 03:47 PM

With more weight forwards Bloodclods buggy is less stable and you can see the rear end stepping out several times, but the fwd means it isn't going to spin out as you don't let off the throttle. More rear weight will make it more stable and easier to drive, but more likely to wheelspin under acceleration. So less rear weight is faster, but a little bit harder to drive.

dodgydiy

01-07-2012, 08:10 PM

well i am going to have to build something..... fwd buggy or fwd rally car, that is the question...... with the motor hanging out over the front to try and get traction, i would have thought you would then want the weight of the battery central on the chassis to make sure the back suspension actually has something to work with. also it might be worth noting that the maxxum was better with 4wd fronts on all corners, it had more traction with the narrower tyres, but also i suppose was mid rather than front motored so had less weight over the front wheels.

Body Paint

03-07-2012, 06:12 PM

dodgydiy

03-07-2012, 06:20 PM

i think that i will be doing the rally car, or maybe even both lol....

forgot to say earlier, has anyone tried messing with the castor angle on a fwd car, i bet it could make a fair bit of difference to traction out of corners

terry.sc

04-07-2012, 07:48 PM

If you want to build a fwd rally car, you've already got plenty of options. Tamiya already make fwd touring car chassis (http://www.tamiya.com/english/products/58463ff03pro/index.htm) but they also make a 4wd rally chassis with a front mounted motor, the XV-01 (http://www.tamiyausa.com/product/item.php?product-id=58526). If you want it fwd all you will need to do is leave out the drive belt between front and rear gearboxes.

dodgydiy

05-07-2012, 10:18 PM

that'd be boring, have to create it yourself!! have lots of tc3 front suspensions parts so would probably go the tc3/b3 direction or similar, as for a buggy, have been rooting through my parts to see what i can use, problem being that most of my 4wd front end parts date back to pre 94, with most originating in the eighties!

my work wouldnt be to the standard of what is in this thread, or probably to bloodclod standards either, but will probably be a little different, will put something up when i get going, and stop polluting this great thread!!

ruf

07-07-2012, 01:34 AM

Origineelreclamebord

09-07-2012, 12:50 PM

Looks awesome! It appears that you've left space inbetween the rear arm mounting blocks for a stick pack. If you decide that short lipo is the way to go, I would consider increasing the size of the blocks/arms to take up the entire rear of the chassis. The arms are super long levers, and they might not survive a side impact or cartwheel well.

I understand your concerns - I have the same concerns. The reason there is no one-piece rear block is because I need some place to take the battery out. I've had a look at different ways to do so (side, rear, rear and tilting upward being the main ones) and I ended up with this setup.

I hope it holds up. If it keeps breaking then some revisions have to be made, but I think the carbon plates at the edges will massively reinforce the blocks. By how much we'll see once the car hits the track :)

Origineelreclamebord

18-07-2012, 02:58 PM

So, it has been a while without updates... Why is that? Well here it goes:
http://i65.photobucket.com/albums/h212/Varockshade/FWD%20Buggy%20Project/Screenshot55.jpg
http://i65.photobucket.com/albums/h212/Varockshade/FWD%20Buggy%20Project/Screenshot56.jpg

The finished design. Finally! :lol:

I've been working on a lot of tiny revisions that are not really relevant to post up. The only two big things I can mention are the addition of the rear wing and the fact that I finalized the front suspension geometry. To be more specific, I combined the approximate suspension articulation and matching ground clearance of the TRF201's rear end with that of the full travel of the damper by adjusting the geometry of the rocker arms:

http://i65.photobucket.com/albums/h212/Varockshade/FWD%20Buggy%20Project/Screenshot52-2Medium.jpg

The plan is to use a Cab forward shell - possibly a cut B44.1 Bulldog shell (like in the first picture) - for this prototype. More pictures and info will hopefully follow soon: I'm currently busy arranging parts and hardware to build the car, which clearly they haven't taught me enough about at school :p

jimmy

18-07-2012, 03:12 PM

Amazing!
Great to meet you in Belgium mate - and I look forward to seeing a running proto!

Nas

19-07-2012, 02:57 AM

Your 3d computer drawing skills are amazing .
Very interesting thread.
The car,the 3d computer skills,the ideas=engineering perfection.

Thanks.

BloodClod

19-07-2012, 03:59 AM

What an awesome thread and I am looking forward to developments in your project! :)

Be glad to offer what little I know on FF buggies if you need.

Glad to see a video of mine still survived. Youtube closed my account and deleted all the videos without warning sometime ago...

Origineelreclamebord

19-07-2012, 07:28 AM

Thanks for the great response! :D I'm really looking forward to the build and to testing it! If my FF01/DF01 FF Buggy was anything to go by, this car should be a blast to drive!

@BloodClod: There were two things I was wondering about your car when I saw the video. First of all, what motor did you run in it, or have you tried several motors? (And if so, what worked best for you?) And secondly, do you recall what other cars were running around it in the video? As it seems you're absolutely flying past them! :lol:

@Jimmy: Thanks! :) It was great being at the Kampenhout GP and hanging around at 'your' corner of the track! I hope to build the car next week, and I'll drive it soon. If things look promising it will entirely replace my TRF201 for racing (for the time span that I can't afford electronics for both cars, that is) and it may also see action at events like the Kampenhout GP!

VikNor

30-07-2012, 12:10 PM

Origineelreclamebord

01-08-2012, 10:00 PM

Very nice work indeed:). Ive been thinking about this myself but came to the conclusion that it would be very hard if not imposible to get the grip needed to clear big jumps with a short runup. No Im not so shure. Cant waith for some action pics

I guess I'll find out soon enough if it's true than it's difficult to clear jumps with a short run up: The track of my club has that :p I have to say they aren't huge jumps, but the run up is next to zero!

Anyway, I got some nice updates! I collected the parts from the post office this morning... I've currently got an assembled car in front of me with working suspension! http://www.tamiyaclub.com/forum/public/style_emoticons/default/biggrin.png I'll take some good pictures tomorrow when it's light again, for now I'll share some pictures from the build:

http://i65.photobucket.com/albums/h212/Varockshade/FWD%20Buggy%20Project/IMGP3053.jpg
The Printed parts and the carbon goodies. Note: On the right are some printed plate parts. Once the first one or two test drives have been done I can get these made from carbon (hence, if any adjustments are needed, they can be done now without wasting money on another new carbon part and throwing the old one away).

http://i65.photobucket.com/albums/h212/Varockshade/FWD%20Buggy%20Project/IMGP3063.jpg
http://i65.photobucket.com/albums/h212/Varockshade/FWD%20Buggy%20Project/IMGP3064.jpg

http://i65.photobucket.com/albums/h212/Varockshade/FWD%20Buggy%20Project/IMGP3067.jpg
http://i65.photobucket.com/albums/h212/Varockshade/FWD%20Buggy%20Project/IMGP3069.jpg
Notice the right driveshaft isn't in it's outdrive? The diff nut and spring are slightly in the way, despite all the CAD work! I can only hope the guy who I bought this 201 from has built the diff wrong (which I have to admit is quite easy, the manual isn't clear about it that you need to flip the diff around at some stage in the diff build).

http://i65.photobucket.com/albums/h212/Varockshade/FWD%20Buggy%20Project/IMGP3070.jpg
http://i65.photobucket.com/albums/h212/Varockshade/FWD%20Buggy%20Project/IMGP3071.jpg
http://i65.photobucket.com/albums/h212/Varockshade/FWD%20Buggy%20Project/IMGP3072.jpg
http://i65.photobucket.com/albums/h212/Varockshade/FWD%20Buggy%20Project/IMGP3075.jpg
http://i65.photobucket.com/albums/h212/Varockshade/FWD%20Buggy%20Project/IMGP3076.jpg

There are a dozen revisions I made on the parts, from small dremeling to potential geometry changes, but overall it looks pretty good: I even have more clearance between all the different links on the front than I expected! http://www.tamiyaclub.com/forum/public/style_emoticons/default/smile.png

jeffrey

01-08-2012, 10:17 PM

i love your work.
i can't wait to see it on track :p

Mr. Pink

01-08-2012, 10:21 PM

Truly amazing! :thumbsup:

I really need to invest in a 3d printer now I think...:p

Edit: Is it ABS plastic?

ruf

02-08-2012, 04:47 AM

Origineelreclamebord

02-08-2012, 07:05 AM

I can't believe that it was cheaper to print those parts than machine them? You have your own printer I assume? Fantastic work. Interesting choice of flipping the front and rear shocks. I hadn't noticed that from the drawings.

I don't have my own printer, they have it at Atomic Carbon. It is an FDM printer (an extrusion proces where it lays down a wire/string of material, forming a layer, and once one layer is done moves to the layer on top of that), they are relatively affordable and it's a quick and cheap way to make prototypes.

I must say though, if some parts are not strong enough I'll have to find a way to make them stronger (for example I think the suspension arms will get a beating and I can't be 100% certain they'll keep themselves in one piece with my driving style :lol:). Machining could prove an option, another option would be to look at more sophisticated printing methods (and thus using a printing service).

All in all though, the parts feel quite strong: You can feel a tiny bit of flex, but they are quite rigid and even the printed plates (that will later be in carbon) seem to be able to handle quite a lot of punishment (screws that rotate enourmously tight at assembly and the printed plate being the only thing I could hold onto with my hands).

Gayo

02-08-2012, 07:29 AM

This is awesome! What a great project, you must be proud! :thumbsup:

As the others said, can't wait to see it running! Will you sell a conversion kit?

ruf

02-08-2012, 08:17 AM

I've been eyeballing this:
http://store.3dprintingsystems.com/index.php?route=product/product&path=62&product_id=101

We'll see what the reviews are once it's out. I'm still looking at Cubify which is more expensive, but their software looks really easy. Trouble there is proprietary spools.

Chrislong

02-08-2012, 09:23 AM

Hope this catches on! Awesome work. :thumbsup:

Origineelreclamebord

04-08-2012, 06:14 PM

I posted pictures of the built prototype in the Atomic Carbon subforum (LINK (http://www.oople.com/forums/showthread.php?p=681139)) - Here are two of the pictures of what it looks like (to make you click the link :lol:):

http://i65.photobucket.com/albums/h212/Varockshade/FWD%20Buggy%20Project/IMGP3090-1.jpg

http://i65.photobucket.com/albums/h212/Varockshade/FWD%20Buggy%20Project/IMGP3094-1.jpg

Burty248

04-08-2012, 06:19 PM

Wow looks amazing.

Good stuff.

Cream

06-08-2012, 10:35 PM

Looks great.

ruf

07-08-2012, 05:42 AM

fantastic!

mro_racing aka Doorbell

08-08-2012, 10:55 PM

we need a video of it on the track :woot:
wish i had a 3d printer :thumbdown:

Naushad

08-08-2012, 10:59 PM

Wow!

Imagine ppl sharing CAD files to make their own model parts...seems crazy concept but it could be the future!

I've been eyeballing this:
http://store.3dprintingsystems.com/index.php?route=product/product&path=62&product_id=101

We'll see what the reviews are once it's out. I'm still looking at Cubify which is more expensive, but their software looks really easy. Trouble there is proprietary spools.

Origineelreclamebord

09-08-2012, 07:13 AM

Wow!

Imagine ppl sharing CAD files to make their own model parts...seems crazy concept but it could be the future!

I don't wish to crush your dreams but often this system is used to get people going and make them enthusiastic, only to start charging money for things once everything seems successful. There are very few open-source (or alike) systems out there.

That said, I really hope I am proven absolutely wrong! In fact, I already shared the CAD models of the Tamiya parts with someone so he could do a tube chassis buggy based on the 201 :) I won't post them online for grabs as I think Tamiya wouldn't be too happy with that, but if anyone needs them they can PM me.

Burty248

09-08-2012, 08:34 AM

Have you been using solidworks for this project? Whats it like and how much is it?

I Would like to do some basic 3d computer modeling myself.

Origineelreclamebord

09-08-2012, 08:47 AM

I've indeed used SolidWorks. We can get the student license for 4 euros at the university, but normally a student version costs 120 euros.

As for a SolidWorks license which allows you to use the software for production purposes as a company (and has the latest updates, the student version is the previous year's version) I've heard you'll pay up to as much as 6000 euros! :eh?:

Whatever the case is, SolidWorks is not basic at all, but it does work very well - Once you get to understand the 'SolidWorks-logics:' The thing is, it's not extremely intuitive. It's hard to make such a complicated piece of software with this much capabilities without making things impossible to follow for a stranger to SolidWorks.

However, I think they do have nice tutorials incorporated in the software: Once you've done one of the tutorials, the rest will go easier, and once you get a feeling for using the basic steps in making a model you can start playing around and do all sorts of crazy stuff! :thumbsup:

There are plenty of cheap or free alternatives. I haven't used them as I already have this software (and there is nothing the free CAD packages can do what SolidWorks can't other than save you money - but for me not a lot either). I've seen some very impressive work in Google SketchUp, so it might be worth having a look at, and I've worked in Anim8or (http://www.anim8or.com/main/index.html) when I was younger - I recalled it was fun and that people had made amazing stuff in it, but whether it is compatible with CAM or even practical when you need measure and remeasure a lot I don't know.

Burty248

09-08-2012, 10:03 AM

Hmm that sort of price tag is a bit high at the moment. Thanks for the indepth reply though.

Might be somthing I come to later.

smokes

09-08-2012, 12:17 PM

Hehe thanks for the tip! I removed them to reduce the chance of errors in SolidWorks: It seems SolidWorks just can't seem to understand ball joints and concentric mates very well if you have a lot of them. Apparently removing the front links wasn't enough, as it doesn't listen to any of the concentric mates I set anymore: The ball connectors don't stay in their adjusters anymore whilst it did work yesterday. Ah well, time to re-assemble the low - again :thumbdown:

Anyway, to come back to your point: I checked yesterday if the upper links would fit. They need to move to the front a bit, but it will fit. It's almost too tight for comfort, but it will have to do :lol: The DEX210's inner rear adjusters may help to create a little more room by the way.

to mate ball joint in sw by create a sketch point in the spherical center of ball and ball cup, select to sketch points and do a coincident mate.

Origineelreclamebord

09-08-2012, 02:34 PM

to mate ball joint in sw by create a sketch point in the spherical center of ball and ball cup, select to sketch points and do a coincident mate.

That's a VERY good idea, thanks!!! :thumbsup: It seems it just can't solve all the concentric mates without failing at some point :lol: Time to edit that and make a new assembly of the lot then!

DANNYHOCKIN

10-08-2012, 12:37 AM

Origineelreclamebord

10-08-2012, 07:01 AM

I purchased alibre design expert software. It's not near the level of solidworks but for someone that wants to learn modeling software on their own, it's pretty cool. Best part about it......... It's WAAAAAAYYYYY cheaper than solidworks. :o

They just started selling 3d printers too. Hmmmmmmmmmmmm.......

http://www.alibre.com/

That's one to watch and try out when the end of my study draws near! :) I want to use software legally if/when I start my own business, and I know there is a lot out there beyond SolidWorks - though I understand for a uni it is financially more attractive (and more time efficient to use only one CAD package).

Edit: Just watched a video of the part modeling... The way of working used in the discussed features is pretty much identical to what you have in SolidWorks... Nice! :thumbsup:

smokes

10-08-2012, 01:45 PM

That's a VERY good idea, thanks!!! :thumbsup: It seems it just can't solve all the concentric mates without failing at some point :lol: Time to edit that and make a new assembly of the lot then!

I made 1/12th scale model of a CRC t-force I have put it on Grabcad have a look at that if you have SW2011 or higher. that will allow you to see the Ball joint mates.

moker

11-08-2012, 05:50 PM

http://www.youtube.com/watch?v=y5C378lYU6s (http://www.youtube.com/watch?v=y5C378lYU6s)

Origineelreclamebord

11-08-2012, 06:49 PM

http://www.youtube.com/watch?v=y5C378lYU6s

Thanks for posting this! :thumbsup: I really appreciate the support from people at the event:

1. Cool responses and advice as how to improve the car or what could be worth trying out on it.
2. Video and photo footage!
3. The support on getting the car up and running (when it broke down).

Break down? Yes, it did. The end of the video shows the car sagging, and it was one of the ball connector nuts undoing themselves of the screw (no loctite, woops)! However, I had some breakage of 3D printed parts - hence why I was not jumping the car. I hope though it still gives an impression about the car.

Some info about track, conditions, car and setup:

Track & Conditions:
Clay surface, dry, very bumpy and quite dusty.

Car:
12T/3100kV Motor, Sensorless
Total weight: 1470 grams (just a few grams too light for BNK regulations).
Weight on front: Approx 1100 grams.
Weight on rear: Approx 370 grams.

(For comparison, my TRF201 was 1560 grams in total, 1030 grams on the rear, 530 on the front).

Setup:
Front Tires: Proline Caliber M3 (nearly new)
Front damping: #300 oil (Tamiya)
Front spring: Associated 'Rear' Red
Rear Tires: Proline Holeshot M3 (nearly worn down to slicks)
Rear damping: #300 oil (Tamiya)
Rear spring: Associated 'Front' Blue

The setup proved to have too little damping (not surprisingly actually, I just threw them on there on the build, my TRF201 uses #400 oil on the rear and #500 on the front. The springs seem slightly too soft up front, and I may need softer ones on the rear. I don't know how visible it is in the video, but from the rostrum you could see the rear wheels bouncing like they were on drugs :lol:

PS: The applause was for finishing the first lap, as the first time they saw it run it broke down on the first jump!

moker

12-08-2012, 06:42 AM

http://i472.photobucket.com/albums/rr90/moker/IMG_1634.jpg

Origineelreclamebord

13-08-2012, 08:24 PM

http://i65.photobucket.com/albums/h212/Varockshade/FWD%20Buggy%20Project/IMGP3150.jpg

http://i65.photobucket.com/albums/h212/Varockshade/FWD%20Buggy%20Project/IMGP3148.jpg

The first breakage of the day: the (temporary) plate that holds the rear suspension blocks for the front arms. It happened on the first jump when I tried to roll over it but went slightly too quick. The front end dropped about 20-30cm and it broke in half.

Luckily some people helped me to do a trackside repair: a cut up piece of motor guard from one driver, a Dremel from another driver, a bit of creativity and I had it back up and running within an hour or so. This repair enabled me to run all the other laps with the FF the rest of the day... about 20 of them.

http://i65.photobucket.com/albums/h212/Varockshade/FWD%20Buggy%20Project/IMGP3153.jpg

http://i65.photobucket.com/albums/h212/Varockshade/FWD%20Buggy%20Project/IMGP3154.jpg

http://i65.photobucket.com/albums/h212/Varockshade/FWD%20Buggy%20Project/IMGP3155.jpg

This is the broken suspension arm. It's a strange breakage: The suspension shaft is still on the car and it came off in a slight brush with a kerb. If you look closely it seems the part delaminated (cracking through a layer here and there switching to another layer). There is almost no material that broke away when the arm came off (and what broke off broke off in an odd place. The cracking probably happened on the bumps and the hops it made in those laps, making a crack. The brush against the kerb was enough to flex the material and pull the arm off the suspension shaft.

There are carbon parts and stronger 3D print parts on the way so I can soon test it again, but I'd prefer to have something as a backup for the upcoming event, so if I can find time for it I'll also make some arms by hand from a plate of material (probably sacrificing a cutting board or something) :)

metalmickey0

13-08-2012, 09:32 PM

Looks cool running and yes i did thinmk it was a bit light and bouncy at the rear end.

Cream

13-08-2012, 11:21 PM

Think maybe your expecting a bit much of 3d prints. Don't think they are really intended for running. More a look what we can produce item. prototyping. i.e proving the model.

mattr

14-08-2012, 06:22 AM

Yup, we just use them to create something to hand round in meetings and maybe do some fit and form testing. They never get run. Or at least, they don't get run for long (before they explode!!).

If you have the models you used, you can probably get one of the guys on here to machine a set up out of something more suitable. Or even go for a more complex shape to reduce weight/tune stiffness.

Origineelreclamebord

14-08-2012, 06:37 AM

Think maybe your expecting a bit much of 3d prints. Don't think they are really intended for running. More a look what we can produce item. prototyping. i.e proving the model.

I guess you're right about that - with this material and printer. I've tried models (Rear suspension blocks for the Dyna Storm (http://www.shapeways.com/model/649158/tamiya-dyna-storm-etc-rear-blocks-d1-d2-v3-01.html)) SLS printed from Nylon - They only failed after a lot of crashing and cartwheeling.

Knowing that the part from this (vintage) car is known to fail quite easily (and therefor is quite rare), this part keeps the runners from ending up on the shelf or in an old box (because owners can't find the replacement parts). Coming from that and having seen how accurate and strong 3D printed parts can be (even if they are not nearly as strong as reinforced plastics), I put a lot of faith in them :)

Mr. Pink

14-08-2012, 08:01 AM

How about making additional holes so you can place some zip-ties around the parts of your wishbones where the shafts are?

VikNor

14-08-2012, 09:46 PM

Nice:). Some stronger parts and some work with your setup and you got a potentialy fast 2WD:). With all that weight on the front i would have startet with the stiffest springs you can get your hands on in the front and the softest in the rear and go from there.

Naushad

14-08-2012, 11:08 PM

That's looking great....you've certainly achieved a lot there and filmed it!

I agree with a lot of the above comments..."a proper" proof of concept car is what's needed to take it to the next level i.e. with the stronger wishbones etc..

Obviously, try some better (i.e. less worn) rear tyres on your next trial..this may well help handling a bit alongside a change of spring/oil.

Origineelreclamebord

15-08-2012, 05:41 AM

Thanks for the suggestions :)

I've contacted a member to get the parts machined (probably from Delrin).

I'm also looking at an alternative to make is possible to produce the parts by laser cutting+drilling all the necessary holes afterwards with a bench drill. This method might enable me to produce suspension arms at the uni's workshop - if the laser cutter has enough power to cut through 8mm of polycarbonate - and if the employees there allow me to. They seem to be really strict about what materials should be machined/cut etc: They pretty much only let you cut Plexiglas and cardboard with the laser cutter - I guess it's time to push them to become more ambitious! :lol:

Setup-wise, I've just ordered Losi Silver (3.4) and Losi Green (3.7) 2.5" springs (I used the 2.95 AE Red springs in the video) for the long/front dampers. As for the rear/short dampers, I think AE Silver (3.85) or AE Green (3.5) could work (I used 4.2 AE Blue springs in the video). Like I mentioned before, the oil will go up from #300 to #400 or #500.

Note: All mentioned rates are lb/in.

Someone also suggested a stabilizer for the rear - I think this might help to reduce the loss of wheel pressure on the inside front on power (thus meaning more forward traction)? :eh?: Also, it could prove interesting as a means to force a little oversteer on the rear.

Which brings me to your point Naushad... The slick tires didn't seem to affect it's handling much on the first drive, even in the dusty conditions... but it's future 6.5T/5200kV motor (instead of 12T/3100kV) and some big changes in the damping and spring setup coming up, it may be a whole different story on rear slicks! :lol: I also think that when I start testing the car on astroturf, the rear bite will be more important to keep it stable.

Origineelreclamebord

17-08-2012, 10:23 AM

As the first test run(s) have been made and I've worked on the car a bit I've now experienced the original design, and I've come with some updates for the car. I'll share with you the bigger changes to the car:

http://i65.photobucket.com/albums/h212/Varockshade/FWD%20Buggy%20Project/Screenshot62.jpg

http://i65.photobucket.com/albums/h212/Varockshade/FWD%20Buggy%20Project/Screenshot60.jpg

Most obvious probably is the holes in the suspension arms. This allows to increase the print fill without using more material: In short, the part is reinforced in the crucial areas.

The sidepods are not really as much a revision as something I couldn't model until I knew the approximate width of the body that would go on the car.

Keen eyes will also have spotted the following update:
http://i65.photobucket.com/albums/h212/Varockshade/FWD%20Buggy%20Project/Screenshot61GIF.gif

On first glance it would affect the car in a bad way: higher CoG and weight balance further to the rear (and slightly outside). Upon the build of the V1.0 parts I came across a problem: the rear end had too much suspension movement when using the upper and lower middle holes. The only solution was to use the top hole on top and the rear of the three mounting holes on the suspension arm. I also found I needed a lot of spacing (some 5mm) to mount the damper to the rear of the three holes. The revised version solves these issues, as well as making sure the outermost settings are not used for what should become the basic setup of the car.

(The image also shows extra material around the rear axle on the rear suspension arm and the text on the side instead of the top of the arm).

Moving to the front end, I found that the outside wheel didn't seem to have enough steering compared to the inside one: the Ackermann angle was off. The image below is approximation of the old and new Ackermann geometry at approximately level suspension arms:
http://i65.photobucket.com/albums/h212/Varockshade/FWD%20Buggy%20Project/Screenshot59.jpg

It's quite a difference :lol: Thanks to making the steering plate 10mm? wider (and putting the ball joints, which are the pivoting points of the steering plate, also 10mm further apart) the new geometry is reached. The inside wheel should still pull to the same angle, whilst the outside wheel on the new geometry is pushed to a bigger angle than before (some 5 degrees I think)? I think this should remove some of the understeer the car had, along with less tire wear and the ability to accelerate a little earlier out of the corners. It should also have a smaller turning radius (though I'm not sure how much use that is as long as the car can run on it's 'best' racing line).

And last but not least, I did some improvements to make maintainance easier:
http://i65.photobucket.com/albums/h212/Varockshade/FWD%20Buggy%20Project/Screenshot63.jpg

The rocker arm/steering frame was difficult to remove, making the whole top chassis time consuming to remove (which in term makes it an absolute pain to replace/setup/change anything on the front lower suspension or gearbox).

Using some embossed pieces with hex shaped debosses in them, the strength of the original part is retained whilst also enabling me to undo the part just using a screwdriver. In addition to that, I decided to add more material around the rocker arm axles, as well as using large fillets to distribute stresses better.

The frame that holds the top mounts of the dampers was also rather an unpractical part. It's still not optimal (removing it from the top chassis won't go very quickly, but at least now the dampers can actually be removed from the block without taking the whole top chassis plate off :lol: (It's not visible how I solved that on this picture, I'll add it later).

That's all for now... I'm curious to see what effect the updates have to the track and trackside experience :)

av4625

17-08-2012, 10:28 PM

Setup-wise, I've just ordered Losi Silver (3.4) and Losi Green (3.7) 2.5" springs (I used the 2.95 AE Red springs in the video) for the long/front dampers. As for the rear/short dampers, I think AE Silver (3.85) or AE Green (3.5) could work (I used 4.2 AE Blue springs in the video). Like I mentioned before, the oil will go up from #300 to #400 or #500.

Note: All mentioned rates are lb/in.

U will want softer springs on the rear than the front not sure how ur gonna do this with rear shocks on the front and fronts on the rear

av4625

17-08-2012, 10:33 PM

http://www.youtube.com/watch?v=y5C378lYU6s (http://www.youtube.com/watch?v=y5C378lYU6s)

it actually looks really good for a complete proto more or less

smokes

18-08-2012, 07:24 AM

Why have you pushed the gearbox output cup so far forward of the front wheels axle line?
The universal Joint used in rc cars will cause chatter when run at a angle. Due the of velocity sinusiodaly changing dependant on angle that the joint is bent at.

See the maths here

http://en.wikipedia.org/wiki/Universal_joint

It a potential stress and vibration problem and means in a straight line the wheel velocity is contantly changing.

Also the rear trailing arms are long are you putting track arm
at the bottom of the rear wheel hub to control the side load?
You may have an issue with the hingepin being subjected to a bending moment whinch fatigue the arm or snap the are and the hinged joint.

Origineelreclamebord

18-08-2012, 10:04 AM

Good question - ideally the driveshafts should indeed be (almost) colinear from the top view.

The answer to the outdrives being so far forward has come from a lot of work and mockups with the steering, suspension and driveline. The thing is, if the driveshafts are in their 'ideal' position, the steering arms will be in the way of the suspension arms if I try to get a good ackermann angle - not to mention the gearbox is also kind of blocking the way for a compact steering system. I could put the steering arms higher up, but that's where the inboard suspension is at. The inboard suspension is used because there is a lack of space around the slipper clutch/camber links/steering links/driveshafts. And then there is the weight balance to consider as well.

So at some point somewhere, you'll have to compromise. I know at full deflection these driveshafts don't rotate very smoothly, but so far on the pit table it seems the driveshafts are not deflecting to their full angle as they seem to rotate without clicking, binding and other grim sounds :lol:

For now I've got a couple of things to sort out on the car: Basic setup on astroturf and clay, then to test it's capability to keep up with RWDs, and how well the car does in a race: How quick is it off the starting line? How quick is it compared to an RWD if you need to go off the FWDs racing line to defend or attack? Is it reliable enough? Are the trailing arms a problem if someone drives into you?

Then once I get to know the car's character and basic performance, I can start looking for the areas to update and (attempt to) improve :) I think the driveshafts won't be the first on the list, but if it does seem to chatter it will be very important to look at (especially with the smooth power delivery this car demands).

As for the trailing arms, I'm curious to see how it'll perform in the long term. The forces at play there will be considerable - it's something to have a good look at after every run to see if there is no damage or wear. Maybe it'll need 4mm hinge pins, who knows. If I can afford a weight balance that's further to the rear I could opt for a longer chassis, making more space for electronics in the process.

Who knows what I'll end up with, for now though I just want to get a car reliable enough to last a race meet without breakage and get it around in a constant pace :)

terry.sc

18-08-2012, 10:51 PM

As for the trailing arms, I'm curious to see how it'll perform in the long term. The forces at play there will be considerable - it's something to have a good look at after every run to see if there is no damage or wear. Maybe it'll need 4mm hinge pins, who knows.
I think the comment about the trailing arms is more due to the twisting loads on them. The pivot pins are not far from being lined up with the rear axles, but with the damper mounts being on the inside you have the spring pushing down on the inside edge of the arm while the wheel is pushing up on the outside edge of the arm. The twisting force on the arm would be greatly reduced by mounting the shocks in the centre or even on the outside of the arms.

smokes

19-08-2012, 08:12 AM

You may find that you need to design your own gearbox case which will reduce the design compromise.

I would try using solidworks simulation express an simulate the arms been subjected to a side load to see where stress concentration is on the arm and what load it will fail at. And then simulate it wit a fixed point benhind the wheel and see how much the stress in reduced and the max laod it will take. It would be better to use the professional simulation tools that SW provide as you and section the mesh and put differnt type of fixings in the simulation.

P.S I would also put in all the fixings you are using, in the model. If you don't have SW toolbox use the mcmaster carr site they have all the screws nuts and bolts modeled up.
I learnt the hard way in engineering why you need to put the fixings in assembly.....

A reading list.

You should also get your hands on a copy of Milliken's Race car vechicle Dynamics.

Heinz Heisler books on advanced vehicle technolgy and a copy of the latest edition of the bosch automotive hand book.
And the latest edition of the machinery handbook for a basic referance of engineering standards and calculations.
Also get a copy of roark formulas for stress and strain.

Origineelreclamebord

13-09-2012, 03:12 PM

Sorry for the radio silence in the last few weeks. The focus has been on school for the past two weeks or so, and it's hard to find time to work on the project.

I've got the new parts in from Jonathan - the embossed pieces make the car a lot easier and quicker to work on, and it seems the new steering plate works much better for the ackermann angle.

I've also done some setup work: #500 oil (Tamiya) and Blue springs (AE) on the rear (in combination with the new shock tower/lower shock mounts) and #400 oil (Tamiya) and Red springs (AE) on the front.

The car has much better damping already, though it seems the front needs more damping (also #500, or perhaps #600) - it may also need stiffer springs up front (but that's on tarmac anyway).

The new steering plate does help at lower speeds, but at higher speeds (+on power) I still find it rolls too much and it has significant understeer - off power it is good - That means there's probably too much weight transfer? :eh?:

Edit:
Good news! :woot: I've finally got laser cut parts of decent looking accuracy and finish at school. Polycarbonate was a disaster (smoke, stench, burnt/black edges and the disapproval from the teachers at the workshop), but Delrin works a treat! It takes time, and the finish is not as good as PMMA/Plexiglas, but overall it looks really good! These parts after drilling the holes for the hinges should be enough to handle jumping punishment! :thumbsup:

Origineelreclamebord

28-09-2012, 05:47 AM

I'll continue my last post here... I've cut the suspension arms and rear suspension blocks with the laser cutter and drilled holes in them - Their finish isn't very neat and it's accuracy is not 100%, but I think it will be good enough being such a rough prototype.

If I can find the time then I'll be updating the spring+damping setup tonight, and if all goes well then I will be testing it tomorrow on clay. With the Delrin arms I should be able to try some jumping, though I think the rocker arm system will really be put through it's paces by that.

So what can I say? I can't wait to give you guys an update early next week! :)

Origineelreclamebord

01-10-2012, 08:17 AM

Update time!

I drove the car on saturday... Wow! :D The car seemed ok: Better damping/spring setup, quicker with the more powerful motor - eventually anyway :lol: The car had loads and loads of wheelspin. Also, it seemed to understeer the same or more as the first test - back then I didn't get the chance to push it, so that might contribute to that.

I got a set of 4WD front Proline Caliber tires (with a cut profile) mounted on rear wheels from one of the fellow drivers and I put it on the front end. The understeer was reduced considerably and the car seemed like it had a better aid to put the power down, too. It could be down to the narrower tires. Also, the tires seemed to balloon less. My theory: this may help in the corners, where the inside tire tends to balloon a lot, pushing the car into sort of a roll and losing a lot of drive on the outside wheel.

Another big thing I found out... It's durable enough to jump, and it was very manageable to jump it. In fact, I think this car flew easier and was easier to adjust in the air than my TRF201 was with that (sensorless) motor fitted! :thumbsup: I was expecting a tendency to do nose-dives, but it seems the car is pretty stable in flight and can even be flown with the front end as the highest point of the car :o

I wanted to film and photograph the car, so I asked a good driver to try it out. He showed it was easy to adjust the roll in flight as well - for him anyway, I don't trust myself with trying that sort of stuff :lol:

During the testing day I spoke with a lot of drivers about the car and got some great advice. In combination with the test day I got a good list of revisions for this car alone:

1. Do away with the 'swept' driveshafts.
2. Reduce the kickup as far as possible.
3. Revise the front shock system (rocker arms, rocker arm position, deflection/movement of the rocker arm, front shocks perhaps)
4. Add more droop to the front suspension.

Here are some pictures of the car, in and after action:
http://i65.photobucket.com/albums/h212/Varockshade/FWD%20Buggy%20Project/FWD%20Buggy%20Test%2029-09-2012/IMGP3685-1.jpg

http://i65.photobucket.com/albums/h212/Varockshade/FWD%20Buggy%20Project/FWD%20Buggy%20Test%2029-09-2012/IMGP3701-1.jpg

http://i65.photobucket.com/albums/h212/Varockshade/FWD%20Buggy%20Project/FWD%20Buggy%20Test%2029-09-2012/IMGP3723-1.jpg

http://i65.photobucket.com/albums/h212/Varockshade/FWD%20Buggy%20Project/FWD%20Buggy%20Test%2029-09-2012/IMGP3730-1.jpg

http://i65.photobucket.com/albums/h212/Varockshade/FWD%20Buggy%20Project/FWD%20Buggy%20Test%2029-09-2012/IMGP3765-1.jpg

http://i65.photobucket.com/albums/h212/Varockshade/FWD%20Buggy%20Project/FWD%20Buggy%20Test%2029-09-2012/IMGP3814-2.jpg

http://i65.photobucket.com/albums/h212/Varockshade/FWD%20Buggy%20Project/FWD%20Buggy%20Test%2029-09-2012/IMGP3815-1.jpg

http://i65.photobucket.com/albums/h212/Varockshade/FWD%20Buggy%20Project/FWD%20Buggy%20Test%2029-09-2012/IMGP3820-1.jpg

http://i65.photobucket.com/albums/h212/Varockshade/FWD%20Buggy%20Project/FWD%20Buggy%20Test%2029-09-2012/IMGP3822-1.jpg

http://i65.photobucket.com/albums/h212/Varockshade/FWD%20Buggy%20Project/FWD%20Buggy%20Test%2029-09-2012/IMGP3827-1.jpg

It's just one of the 150+ pictures - and I also have 3 videos. So... you can expect a compilation of that soon! While I'm working on that, enjoy the pictures! :)

Edit: Videos:
http://www.youtube.com/watch?v=f2QPP6eNQKo
http://www.youtube.com/watch?v=iaKl5jOdzxQ&

johnnygibbon

01-10-2012, 12:00 PM

smaller wheels like 2wd fronts on the rear axles should help understeer
it did with the maxxum - less grip i prsume
still looks awsome
and it flys !!!!!!!

Origineelreclamebord

01-10-2012, 02:40 PM

Thanks for the advice :) Narrow wheels and tires would be preferable on the rear, even if were only for less mass on the rear. I see why lower grip rear tires might work, so it's definetely something to test! BRCA regulations don't allow it right now to use narrow wheels, hence why it runs wide rear tires.

I'm sure though that there are things to try out to reduce grip: different compounds, other profile tires, the use of different or no inserts, and of course these options should be tested against using narrow rear tires. Not to mention that a similar test should be done on the front. I guess that will happen somewhere in it's development - I can't exactly say when, but it's good to test the car on the different rubber people might run the car with.

mro_racing aka Doorbell

03-10-2012, 07:48 PM

try a tight diff if your looking to have more front end on power

Benh

04-10-2012, 09:11 PM

Would it be possible to manipulate the inserts in the rears to try and reduce the contact patch. Might end up quite firm in the centre but might be enough to get the result without breaking the rules?

mrspeedy

04-10-2012, 09:48 PM

A couple more things to add to your list of things to try ...

Trim out that huge rear wing, I'd get rid of pretty much all the back section of it so you lust have the flat plane and the end plates ...... and how about bald rear tyres if you want less rear grip .... oh and a geared diff if possible ?

Origineelreclamebord

05-10-2012, 07:00 AM

Thanks for the advice guys :)

Re the diff options: The ball diff can be tightened by 1/4 to 1/2 - I'm not sure though that's a good idea with steel balls. It's noted though, I'll try that.

I also want to try a gear diff - sooner or later. It would be interesting to see what the different construction does to the forward traction - and if with the thick oils you can find better forward traction without making the car understeer too much.

As for the rear tires: there are so many things to try out - I could use stiff inserts, completely rigid inserts, glue the majority of the width straight to the rim and use only a small ring of the actual tire as a contact patch... In the end though, it's also about finding solutions that are easy to use as well as within the rules. I think playing with inserts and the tiretread would be the best options.

Lastly, the wing. Now I know it jumps stable (with this wing), I can start looking at the affects of running (and flying) it with less or no rear downforce :)

Hpi_guy

05-10-2012, 04:39 PM

What about predator style and use a front wing

Origineelreclamebord

12-10-2012, 03:25 PM

It could work, yeah :) It's already got some kind of cab forward story going on at the front, and I suppose more front downforce can't hurt performance. I'm not looking to make a 2008 F1 style car though:

http://www.caradvice.com.au/wp-content/uploads/2008/10/china2008_massa_01.jpg

It's as if they used the amount of 'aero' stuff on the car as a cloaking device for the technology that made the car go fast :lol:

Origineelreclamebord

26-10-2012, 09:34 PM

Update Time:

OLD
http://i65.photobucket.com/albums/h212/Varockshade/FWD%20Buggy%20Project/Screenshot68GIF.gif

NEW
http://i65.photobucket.com/albums/h212/Varockshade/FWD%20Buggy%20Project/Screenshot67GIF.gif

Do you spot all the differences? :)

It's new geometry for the rocker arm system up front. In the last test I was made aware that the rocker arms were hitting extreme angles - causing a lot of forces to be applied onto the axle of the rocker arm, and not actually into the rotation (=into the damper). This may make the suspension less consistent - and it sure will compromise it's durability.

Also, it turned out that the car had less droop on the front end in practice than in the CAD model - in fact the droop of the car was quite low (only a few millimeters really). The new system allows for a lot of droop, so much that I'll probably be running internal shock limiters :lol: At least then I'll be able to adjust the droop accordingly.

On the 11th of November I'll have my next racing event - I will take the car with me next to my TRF201 - and I'll probably be driving this car or the TRF201 in the 4WD class (it's a club race, so it's not a big deal) so I can get the most from the few events I'll be able to visit this winter :) I hope I'll have the new parts in by then, it promises to be a lot of fun!

dodgydiy

28-10-2012, 09:37 AM

4wd front tyres were definately better on the maxxum when i had it, although they were on the narrow front wheels, not the rears as you ran them. they gave more consistent steering and more traction, i would say it is probably the more weight on a smaller area helping them to bite in better. if you do try a geared diff, dont go too heavy on the oil it may help with traction but will take away quite a bit of the off power steering, tried mugen diff grease which was like treacle in the maxxum and it was awful. much better with standard lm grease

Origineelreclamebord

28-10-2012, 07:33 PM

Cool, thanks for the advice :) I do need to find out how much it was the tire width that contributed to the grip, and how much the cut tire profile - I used a similar cut profile on the rear of my TRF201 and the increase in bite (mainly forward traction) was huge! Perhaps I can make drive wide uncut vs. wide cut tires to get an impression of the differences just that gives.

As for the diff, I'll keep it in mind if I try it out. To be honest though, so far on all test runs I don't recall a lot of off-power running :lol: To be serious though, I really can't use less off-power steering: It's already a bit pushy turning into corners.

johnnygibbon

28-10-2012, 11:43 PM

i also found 4wd fronts best and i would recomend trying differant wheels and tyres on the back it massivley affectedsterring and hadeling on my maxxum
and as for the diff i say lock it and boot it
fwd is all on power steering
keep em coming dude

Mike2222

19-12-2012, 02:06 PM

Origineelreclamebord

19-12-2012, 05:10 PM

Builders of front wheel drive cars may be interested in the BRCA tyre rule change at the last AGM. Control tyres on 2wd cars are now on the driven axle, not necessarily the rear axle. The other axle tyers are free choice. (1/10th off-road section rule 23.11)

Thanks for the post :) It's an important change for this project - it might be a slight disadvantage for getting the optimal forward traction, but of course it does mean the car's rear suspension can become lighter!

martin_lawson

01-01-2013, 10:32 PM

Love the design! I converted an original Couger to FWD years ago, everyone laughed when I turned up at a club meet with it until I was beetling them all!!
Also built a mid motored 2WD in the mid 90's, made me laugh when I returned to off road to find that was now the norm.

Great to see someone thinking out of the box!
Wish I had the time to scratch build cars again.

Keep up the good work!

Martin

Origineelreclamebord

13-01-2013, 09:46 AM

Sounds very nice Martin :) Do you have any pictures of the FWD Buggy that you could share?

Speaking of pictures... The buggy has made it's international introduction at the EOS in Langenfeld :thumbsup:

Unfortunately it wasn't for racing purposes... It was my first time to drive on carpet, the track was quite unforgiving (the jumps demanded you to get into their 'flow' - which I found very difficult) and I run the hardest spring setup I have - which is a decent setup for dirt and clay - so I couldn't really set up the car for the track.

That didn't stop me from running the car though... A bit on (wet) astroturf outside (which went quite well with the setup+Schumacher Full spikes up front), and a brief run on saturday on carpet (after all the heats, and running Schumacher Mini pins up front).

The result? Huge forward traction without wheelies! (Try that on full power you RWDs!) :lol: I think when driven well an RWD can still beat it's forward traction, but the difference should not be nearly as pronounced - I was surprised and very impressed by that!

However, it wasn't all fun. I couldn't properly brake before corners: The car braked strong enough to make stoppies, and even if you didn't do that, on turn-in the rear end would just break out. I did manage to keep the front end at the front a few times - this resulted in a stable car (as long as I didn't decelerate) with seemingly less understeer than on dirt.

I think to get it really working on carpet it needs a stiffer front end for these high-bite conditions, increase rear droop and decrease front droop - and if that doesn't work... weight on the rear :eh?: I'd do a lot to prevent that though, the forward traction was unreal and I want to keep it that way! :woot:

cryer-evo

13-01-2013, 11:36 AM

this car looks sweet mate are you ever going to put it into production ?

Origineelreclamebord

13-01-2013, 11:41 PM

this car looks sweet mate are you ever going to put it into production ?

That's the ultimate goal of course! :) However, 'production' is very relative. It will be hard to create high demand for a car like this - it'll have to prove itself through performance to even make a chance to appeal to the masses.

So if the car becomes good enough to sell conversions of it will be a challenge getting the conversion affordable without compromising the design... First I need to get to that stage though where the design leaves RWDs eating dust (and/or shredded bits of carpet)... :lol:

Origineelreclamebord

14-01-2013, 03:11 PM

Ok, update time! I implemented a few revisions :)
http://i65.photobucket.com/albums/h212/Varockshade/AC210FF%20Project/Screenshot9-2.jpg

http://i65.photobucket.com/albums/h212/Varockshade/AC210FF%20Project/Screenshot10-2.jpg

http://i65.photobucket.com/albums/h212/Varockshade/AC210FF%20Project/Screenshot11.jpg

I decided to give the car a new gearbox, new chassis layout, upright shocks, new suspension geometry and eh... I think I didn't mention it's just a new design from the ground up? :lol:

To get into it in a bit more detail, these are the main features/changes:
1. DEX210 Gearbox (To allow 3 vs. 4-Gear and Ball vs. Gear diff testing).
2. Team Durango as main supplier of donor parts (I hope this speaks for itself when I'm using a Durango gearbox).
3. Upright shock layout (To focus on just one oddball feature on the car at a time and make the car easier to understand and improve on - I'd love to return inboard suspension back in the equation when I have gathered enough knowledge on FWD).
4. Driveshafts in line with outdrives (To reduce drive inconsistency due to large angles of the driveshafts in steering and suspension movement).
5. Shorty LiPo across width of chassis (pushing the weight balance further forward, allowing a more compact chassis layout).
6. New chassis layout (This time around taking into acount it has to have room to carry a certain size of electronics :p whilst keeping it as narrow and compact as possible of course).
7. Updated Ackermann and Bump-Steer Geometry (it is to be tweaked somewhat more, but this time around at least not just the inside wheel will steer :lol: And bump-steer is next to zero).
8. Reducing anti-squat/kickup to zero (the current proto had better forward traction when I minimized the anti-squat).
9. Less Parts! (For obvious reasons... Quicker to build, easier and more fun to work on, cheaper to manufacture, and if all goes well just as durable).

I'm quite chuffed with the design. I started only a very short while ago making the first parts, and most things came together without too many problems.

There is only one BIG problem I have to overcome. The length of the DEX210 driveshaft is too short (it's 65, and needs to be more like 69-70mm). The first choice would be using as many existing parts as possible - especially of the machined type like driveshafts - so does anyone have suggestions for this? :eh?:

It's the only conundrum to be solved to finish this prototype and I'm really eager to see this car come to life soon! :)

Burty248

14-01-2013, 04:32 PM

Is the chassis only capable of shorty lipos?
Are you aware of ROAR rule 8.2.3 about shorty lipos in electric cars? i don't thinks it a BRCA or any European rule.

Here's a link: http://www.roarracing.com/?p=1438

Sounds a bit of a stupid rule if you ask me.

Origineelreclamebord

14-01-2013, 05:18 PM

It is yes, and I'm aware of that rule... I wouldn't be too surprised though if they have another rule at the ROAR stating that they don't accept front wheel driven cars at all...

Whatever the case is, rules may be open to change, and if that's not the case it might be possible to bypass them... but if it's only the shorty that is a problem, it's easy making a saddle-compatible version :) I know it's not everyone's cup of tea though to use shorty packs - definetely something to consider, and probably therefor something to work on later on anyway.

mattr

14-01-2013, 08:26 PM

Try 410 shafts, sure they come in a 70 ish mm size

mattr

14-01-2013, 08:41 PM

Try 410 shafts, sure they come in a 70 ish mm size

scrub that, all the C-C lengths are over 70 or under 65.

Tomboo_91

14-01-2013, 09:25 PM

There is only one BIG problem I have to overcome. The length of the DEX210 driveshaft is too short (it's 65, and needs to be more like 69-70mm). The first choice would be using as many existing parts as possible - especially of the machined type like driveshafts - so does anyone have suggestions for this? :eh?:

Mr. Dremel (Janus) made some custom length drive shafts a few years ago. He cuts them and glue them together by using a small tube.

johnnygibbon

14-01-2013, 10:47 PM

awsome work and durango parts to
[ want this car even more now )
the tube extension method on drive shafts works ive seen our race controller do it on woodys car and it worked great
keep up the good work and put me down for a conversion kit
deposit ready any time hahahah

Origineelreclamebord

14-01-2013, 10:56 PM

Thanks for the comments guys :D

Mr. Dremel (Janus) made some custom length drive shafts a few years ago. He cuts them and glue them together by using a small tube.

I thought about this as well - even tried it once for an onroad setup. It's not something I can base my design around just in case it's not durable enough. However, it is a very interesting technique to look at for testing an optimized design of the suspension and driveline geometry once I have a backup system :) So I guess I might start off with 'short' arms and try out longer ones later on with the geometry as intended.

As for the driveshaft lengths... The DEX410 shafts are 61mm (rear) and 77mm (front) - the DEX210 shafts are 65mm - the Xray XB4 rear shafts are 68mm I found out, so very interesting to look at. Lastly, the Tamiya DF03 shafts are 70mm, so together with DB01 axles that might work as well (though 70mm after a good look seems to be just slightly too long).

janus_77

15-01-2013, 06:27 AM

Mr. Dremel (Janus) made some custom length drive shafts a few years ago. He cuts them and glue them together by using a small tube.

http://www.xfactoryrc.com/rc/Tech/ModifiedCVA.php :thumbsup:

Skidrow

15-01-2013, 04:28 PM

I can make CVD bones of B4 type in any length requested in steel one piece if interested-race tested

Origineelreclamebord

04-02-2013, 10:28 PM

Gayo

05-02-2013, 08:34 AM

Fantastic! I like the layout and the fact that the steering link is not on the way of the lipo.
:thumbsup:

Origineelreclamebord

05-02-2013, 05:05 PM

Thanks, I'm glad you like it :) I packed it as tight as possible really, and with the inboard shocks out of the way I could move the steering up.

Anyway, today I decided to model a bodyshell for it:

http://i65.photobucket.com/albums/h212/Varockshade/AC210FF%20Project/Screenshot16.jpg

I want to emphasize here, this was just for fun! I'd prefer to avoid the effort of making a mould for a single shell - this car is still very much a prototype, so it's preferable to avoid making a mould for a single shell :p

It does give a good idea of the kind of shell the car needs though: rather narrow, and quite high (the sidepods are 50mm high with the scoops a whopping 55mm - the cab is about 85mm high. I don't know of a body of these proportions, so I might need to get creative again on an existing body to make it fit :lol:

Typpo

06-02-2013, 03:48 PM

Thanks for the comments and help lads :) I've found a solution that I will start out with:

- TRF201 Axles+Driveshafts (64mm)
- DEX410(R) Hubs+Casterblocks

The car will end up being 240mm-ish, not 245 or 246 like I'd prefer to, but geometry-wise it seems to work fine.

I'm kind of finishing up the design right now... The main things left to do were to optimize the battery tray, make the rear shock tower and finish the electronics install:

http://i65.photobucket.com/albums/h212/Varockshade/AC210FF%20Project/Screenshot15.jpg

It's a bit tight on space if you are not using the top deck, but it is possible, even with the huge Futaba receiver and bulky HobbyKing ESC I will be using.

I hope to have a mockup of the front end on the table soon - Fingers crossed! :)

An additional driveshaft option (should you need it) is Kyosho LA-231. It is 68mm pin to pin with the option of changing the axles. Note the cross-pin at the diff side is about 2mm diameter.

An example can be found here for the picture:
http://www.rc10talk.com/download/file.php?id=70068&mode=view

and here for the thread:
http://www.rc10talk.com/viewtopic.php?f=30&t=29607

Gayo

06-02-2013, 04:03 PM

What is the bit protruding on the right side supposed to be? :)

Origineelreclamebord

06-02-2013, 05:20 PM

An additional driveshaft option (should you need it) is Kyosho LA-231. It is 68mm pin to pin with the option of changing the axles. Note the cross-pin at the diff side is about 2mm diameter.

An example can be found here for the picture:
http://www.rc10talk.com/download/file.php?id=70068&mode=view

and here for the thread:
http://www.rc10talk.com/viewtopic.php?f=30&t=29607

Thanks for letting me know! :D So is that axle on the universal shaft a front or rear axle? If it's a rear axle it may work very to get this car close to that 250mm

What is the bit protruding on the right side supposed to be? :)

Hehe, it's one of the posts that holds the battery holder in place. The battery holder is the front half of the right sidepod - it's fitted with one body clip on the side, and one at the front below the steering rack. It's all a bit tight - to get the battery out still requires a small trick or two, but in practice it should still prove more convenient than the the old system!

Origineelreclamebord

11-02-2013, 10:19 PM

http://www.youtube.com/watch?v=RwbeRkIuSUc

Better late than never... I drove the car on tarmac again to show it to a friend - he was so kind to get some footage of the car. You can see it's got brakes unlike any other car :lol: And as you can see, two rear wheels are overrated when it comes to cornering, too!

It's just lovely how agressive it can be driven into corners :thumbsup: The corner speeds is amazing, the only thing I need to reduce is wheelspin and tire wear out of corners (though admittedly, with all the braking to make those stoppies happen, the already worn front tires were completely bald in two batteries) :p

Data on conditions/setup/etc:
Front tires: Proline Caliber M3 Wide/Rear (About 2mm of tread left at the beginning of the run).
Rear tires: Losi (something... Stud?) tires, 4WD Front (reasonable tread left).
Damper setup: Same as on dirt/clay (see page 7 or 8 for reference on that).
Ride Height, Front: 21mm with 12-ish mm droop.
Ride Height, Rear: 26-ish mm with 1-2mm droop.

mrspeedy

11-02-2013, 10:43 PM

Looks ace !!! Lovin' how it corners like a 80's hot hatch ...

Have you thought about a weighted pinion gear ? It might help thow a little weight forward on acceleration ... kinda like the opposite of a 4 gear tranny on a mid motored buggy ..

johnnygibbon

13-02-2013, 12:39 PM

Looks so sharp and can obviously handle the power
Good choice on the 210 gear box ( upgrade the slipper spacer though ) and its tough and reliable , are you running a gear diff or ball diff , my 210 diff has been great with buds balls ceramic kit in it no probs through months of racing but for the intense pressure and ability to almost lock it with thick fluid a gear diff may be good . Nice to have the option any way

Love this car far to much
Kept up the good work

Gayo

13-02-2013, 01:17 PM

The car seems indeed to handle really well! Oh and those stoppies... :woot:

Origineelreclamebord

13-02-2013, 09:55 PM

Hehe thanks guys :D The car goes much better on high bite than I expected: The forward traction doesn't seem to be the limiting factor to overall pace, agressive turn-in is possible (in fact, it seems it goes quicker that way) and I've yet to see it grip roll - I can only hope that applies on carpet too. I do know it does stoppies even better on carpet (with the same droop setting on the rear) :lol:

I have considered experimenting with flywheels, but it was decided to postpone such mods as I knew quite early on that a next prototype would utilize a DEX210 gearbox. It's adjustability with regard to rotation direction of the motor and internals (in one casing) is after all very useful for this project.

I will try out rotation direction of the motor first, but I'm sure along the line it will get to trying out custom parts to try and find the things in the drivetrain that give the edge! :)

As for the DEX210 gearbox, what's wrong with the slipper spacer? Is that related to the issue with the bearing that tends to break down on the slipper axle? And are there any more things besides that? (Note: my DEX210 is of the very first batch - where everyone was trying to solve those diff issues).

mattr

14-02-2013, 10:14 AM

Yeah, the original space wore down, newer ones are harder. TBH, there was nowt wrong with my original one after 6 months, I just replaced it anyway.

johnnygibbon

14-02-2013, 01:16 PM

Yes the spacer wears and that causes the bearing to brake down due to the pressure
Take a look in the Durango section fit the new hardened spacer
And some associated slipper pads your bombproof . But otherwise my 210 diff and gears have been some of the best and most reliable I have run
Things may wear over time but nothing fails horribly and expensively
Good choice

Origineelreclamebord

21-02-2013, 10:33 AM

Thanks for the details guys :) It's good to hear that the 210 gearbox is as durable as it is adjustable (as long as I keep that spacer in check). And I'll switch to AE pads then when the Durango ones are worn down... Do they fit the Durango spurs? :eh?:

Anyway, I've got some progress to share with you...
http://i65.photobucket.com/albums/h212/Varockshade/AC210FF%20Project/IMGP5499-2.jpg

http://i65.photobucket.com/albums/h212/Varockshade/AC210FF%20Project/IMGP5500-2.jpg

http://i65.photobucket.com/albums/h212/Varockshade/AC210FF%20Project/IMGP5506-2.jpg

http://i65.photobucket.com/albums/h212/Varockshade/AC210FF%20Project/IMGP5502-2.jpg

http://i65.photobucket.com/albums/h212/Varockshade/AC210FF%20Project/IMGP5503-2.jpg

http://i65.photobucket.com/albums/h212/Varockshade/AC210FF%20Project/IMGP5501-2.jpg

http://i65.photobucket.com/albums/h212/Varockshade/AC210FF%20Project/IMGP5496-2.jpg

A mockup of the front end! :D I made this mainly to find out if there are any issues around the driveshafts+outdrives - after all the outdrives are pretty short, so there's not much room to play with.

The current setup is a tad narrow (just under 240mm) - and I need to find a way to get the Tamiya 1.5mm outdrive pins to work in the 2.5mm Durango outdrives. However, it does work fine otherwise, and these particular Tamiya CVDs have an impressive operating angle that's much smoother at extreme angles than the CVDs the current proto uses.

I am going to look at the Xray XB4 driveshafts, as these may add a nice 8mm to the width of the car (if the axles are the same length as the Tamiya ones) - plus, they seem to have the 2.5mm outdrive pins.

As for the rest of the geometry, it seems to function very nicely and seems accurate with the CAD model. It has comparable suspension travel to my TRF201's rear end, the ackermann angle is nice, the camber gain is comparable to other 2WDs and can be adjusted nicely.

The only problem I found was that on full steering the outside tire is awfully close to the damper, and the inside tire is too close to the chassis. The XB4 driveshafts may solve this, and if it doesn't I think I can get away with carving the front piece of the chassis in a slightly different shape and putting the damper mounting holes on the suspension arm just slightly to the inside.

So all in all, with small tweaks I could use this front end :) But before I do I'm taking a peek at those XB4 driveshafts!

mattr

21-02-2013, 11:22 AM

And I'll switch to AE pads then when the Durango ones are worn down... Do they fit the Durango spurs? :eh?:I'm on my third or fourth set of AE pads (i was running 3 durangos for a while!) and they drop straight in, someone did mention on another thread that sometimes they need a bit of a trim, not found that yet myself.

Cream

21-02-2013, 07:31 PM

If I where you I'd put a large rad on the bottom of that shock tower. it will be a stress point and likely to break under impact.

http://img.photobucket.com/albums/v420/Creamuk/RC%20car%20parts/Image1_zpse340c9e6.jpg

Origineelreclamebord

21-02-2013, 09:05 PM

Cream

21-02-2013, 09:32 PM

As long as it clears the motor plate it should be fine. Just looking at it I'd have thought you would get away with about 10mm rad, I'd also look at the corner above and put a rad in there too. Corners create fracture points.

johnnygibbon

22-02-2013, 12:43 PM

loving the mock up , nice to see the development from the cad drawings. as to the shock tower i gotta agree with cream , something stronger may be better suited, maybe just make it a bit bigger so there is more material to take the impact . looking good though,keep up the good work

mattr

22-02-2013, 12:54 PM

Thanks for the advice Cream :) The tower design came to existance when I heard so many stories of 210 shock towers (even carbon ones) breaking because the tower hits the motor plate in a crash. I know I could hack off the top mount for the gear cover or even shim the shock tower backwards a little, but I do kind of fancy the 'buffalo' look that the tower ended up with :lol:

Kidding aside though, durability has priority. It's good you're mentioning it because I didn't really look into the clearance and durability of the front tower. There is a load of room for the shock tower to flex, much more than I expected and more it would ever need I think. I can probably get away with increasing the radius to 4-5mm (it's currently 2mm). Is that sufficient or do you think I need to do more to it (or take a different approach to it)? :)With your high front body shell, i don't think there is any chance of ever getting the tower to touch the motor plate!

It tends to happen when the car is upside down and the tips of the tower snag on the ground then drive the tower into the lug on the motorplate. Or just snap it off.

I just can't see you getting that much load to the front tower as easily as you do on the 210. I'd make the rad as big as i could.

Origineelreclamebord

25-02-2013, 02:44 PM

Good point on the direction of the car with which the tower may 'dig' into the ground. The bodyshell shouldn't be a protecting feature for the rest of the car though, and it isn't: It's lower than the front tower (ok, I admit it, only by 5mm :lol:)

Anyway, I've updated a few things on the design. First of all, the shock tower:

http://i65.photobucket.com/albums/h212/Varockshade/AC210FF%20Project/Screenshot17.jpg

I got rid of the sharp corners in the tower, as well as adding more material to the tower towards the center to reinforce the construction. Keen eyes may also spot I added two mounting holes in between the existing 3 holes I had. I also moved the holes slightly further to the center of the car - this means that the inside hole is only accessible when using small bore shocks, but with small bore shocks the damper can be placed that bit more diagonally.

I had a look at the Xray XB4 CVDs, however, they are actually shorter than the Tamiyas (strange being that they actually say '68mm'), and the head that goes in the outdrive has too big a diameter to fit. So, TRF201 Driveshafts it is!

This meant I could could go to the job of tweaking the front suspension arms a bit. First of all, the suspension arm is 0.5mm longer for extra width and a bit of extra clearance that's needed between diff nut and driveshaft. Another 0.5mm was added to this length so the driveshaft can be shimmed 0.5mm inward, reducing wheel offset just a tiny bit :) Lastly, the lower suspension mounts on the front end have been moved 2.5mm to the inside. This is to solve a small binding issue between the tires (especially ones with fat walls, like Proline caliber tires) and (big bore) shocks on the extreme steering angles. The 2.5mm to the inside, plus 1mm extra length of the arm, should solve this with a bit of a safety margin.

There is some important detailing work left to go, but this is another step in the direction of a working prototype :D

mrspeedy

25-02-2013, 06:22 PM

Excellent work as always ... makes for good reading and I really wish I had your cad skills !!

Just one thing, I would have said that the shocks on the front would make for better front end control if they were mounted as far out as possible, looks like they are pretty close to the tyres on full lock but if they were cut into the wishbones a little, closer to the driveshafts that might help ...

Origineelreclamebord

25-02-2013, 08:04 PM

Thanks :D Very nice suggestion by the way, I didn't think of that! It really adds to the adjustability of the front suspension, which is always nice. However, I do need to make sure the front suspension arm has enough width to ensure it's rigid and strong enough - perhaps I can make a mounting slot in the arm instead of on the side of the arm :)

optiman

26-02-2013, 12:34 AM

I really havent read the complete thread, hence the reason of my question/suggestion;

Is that drivetrain is meant for offroad?
Becuase if is meant for off-road you are going to have some serious with heavy nose dives, been there, done that. I did something very similar to your, but mine had the motor facing backwards with reverse rotation, the turck handled very good, terrific turns, but evrytime was jumping time... catastrophic!!!! No matter how much power, the truck simply nose dive.
Anyways goodluck, seems very nice done, much better than mines!!!

optiman

26-02-2013, 12:43 AM

OK, now that I read a couple of the first replies and tittle I know is for off-road.
A suggestion that you should REALLY consider; Dont put more time into that design(front motor). Rotate the transmission 180 degrees and place the motor midships with spur gear and powering a belt to the tranny. That way you might get away with the nose dive and keep the steering servo close for the steering bracket. I remember when I did mine I used NiMH battery it was all the way in the back and it still nose dive like an olimpic champion diver, and yes heavy wheel spin, but since it was a truck not worse than a Maxxum.

I am trying to get the Cad drawings and pictures(if I took) of the FF truck I did, I'll post them if I find them.

optiman

26-02-2013, 01:04 AM

I did not found the pictures, better yet I found the chassis I made for the FF truck.
Ok, now I remeber, I did want to make it with the rear motor, but ended just like you are doing yours. The battery was all the way to the back. The chassis is aluminum, servo was mounted in one of the vertical plates and the two bolts where for the bell crank steering. The receiver was on the double side tape is.
Hope this helps, but REALLY consider re-design it!!!!
I was AWFUL in the jumps and bad acceleration

Origineelreclamebord

26-02-2013, 09:13 AM

Thanks for the suggestions and pictures optiman. That chassis you have is nicely narrow, looks cool! :) It's a shame you couldn't get it to work well for you.

The car is indeed for offroad. And yes, my prototype indeed tends to nose-dive when driven like a RWD Buggy, but...

...I found only one situation where the car reaaally nose-dived. It was when I was using full power to the motor when I was on the ramp - usually in desperation to get enough speed for the jump.

The thing is, when that happens the wheels don't spin up up a lot anymore because they were already spinning so quickly with all the wheelspin - this lack of acceleration of the front wheels in air causes the car to nose-dive (in fact, my rear motor RWD buggy shows similar behaviour in those situations).

So though it sounds strange, but what I've found is that it's down to driving style/technique: it's essential to prevent excessive wheelspin - it's better for your pace (unless you are running on a surface like loose dirt where tires need to dig in to grip). Preventing wheelspin in general will be good enough to clear jumps in a neat way (all the jumps I've tried, anyway).

And just in case you do need to make some serious corrections to the heading of your car, make sure you have some throttle left to play with when you get off the ramp. This means you need a motor that can make those extra spins in mid-air even if you didn't have any wheelspin. The last proto had a 4000kV motor in it - I think it equates to about 8.5-10.5T - and that was fine for a normal length of jump - in fact, I could make it land on it's rear wheels first with that motor:

http://i65.photobucket.com/albums/h212/Varockshade/FWD%20Buggy%20Project/FWD%20Buggy%20Test%2029-09-2012/AC201FFJumpingReference1-1Small.jpg

The upcoming proto will run with a 6.5T/5200kV motor, exactly the same brushless set as I run in my RWD. Nice to compare the cars' pace on the track, and with this I can't complain about a lack of power, that's for sure :lol:

And as another reference, this was a jump at a very modest rate of throttle to clear the 90 degree turn after the jump:

http://i65.photobucket.com/albums/h212/Varockshade/FWD%20Buggy%20Project/FWD%20Buggy%20Test%2029-09-2012/AC201FFJumpingReferencePicture21-1Small.jpg

optiman

26-02-2013, 02:24 PM

Origineelreclamebord

26-02-2013, 02:44 PM

Yes, that's exactly what happened to my truck. I had to approach the jumps slower than normal and leave plenty of spare power on the throttle for a good mid air flight and landing. Maybe if I would've had used a brushless motor instead of a brushed the truck would've have behaved way better.

It's very useful to hear your experience with it, and a relief that the jumping behaviour shows similarities - then at least I haven't overseen something on the jumping front of these cars :lol:

Like I mentioned, if I desperately try to clear a jump with my RWD and all that the wheels do is spin when going up the ramp, it falls to earth as gracefully as rolling a car off a cliff :p However, with the wheelspin of a FWD, this is indeed more apparent and you get in trouble with it way more easily than a RWD because they usually take off like rockets.

With a brushless setup, you can easily get enough power in the car to make sure you don't have to hold back before a jump to be able to tweak it's stance in mid-air. Then after that all that's needed is to adjust the driving style accordingly: No tire smoke and burning rubber on take-off for competitive lap times :)

Plus, if my theory is correct that the 4-gear setup of the 210 gearbox pushes down on the front wheels on throttle (whereas the 3-gear setup as seen on your chassis and my first prototype pull the chassis out of the suspension), it may also increase the amount with which you can tilt the car backwards with the throttle trigger. It's all theory, but if it's not an improvement I can just use the 3-gear setup.

Anyway, back to the chassis you made... Have you tested it much? I'd love to hear more about what parts you used, your findings, perhaps even mods you did based on that? Documentation on FWD buggies is quite scarce so pretty much any info you can give is useful and interesting :)

Typpo

26-02-2013, 05:36 PM

Thanks for letting me know! :D So is that axle on the universal shaft a front or rear axle? If it's a rear axle it may work very to get this car close to that 250mm

Hehe, it's one of the posts that holds the battery holder in place. The battery holder is the front half of the right sidepod - it's fitted with one body clip on the side, and one at the front below the steering rack. It's all a bit tight - to get the battery out still requires a small trick or two, but in practice it should still prove more convenient than the the old system!

Sorry for the delayed response -- unfortunately my original response did not post upon log in.

LA231 is found in the exploded diagram on page 30 of 33 in the Kyosho Lazer ZX-5 evo manual. It is described as "for front" on page 31 of 33. Also, LA232 on page 32 of 33 is described as "for rear" in the optional parts section. The pin-to-pin dogbone lengths are listed as 68mm and 65.5mm respectively. They appear to share the same axle LA231-02 (I do not know of a reference to verify this.) Though the manual makes distinction between front and rear, I think this distinction is only based on the buggy location (with no difference between the two but pin-to-pin length.)

Based on what I have found on the web, these parts along with Kyosho's LA245 driveshafts and UM510-02 and UM522-02 axles, are all interchangeable. As the number of lines per axle increases, the spacing between the bearing face and the axle cross pin center, increases (relative to the axle with one less line) by about 1mm. I have not measured this to verify.

On this topic, the following reference links may be helpful.

Measurements
http://www.rc10talk.com/viewtopic.php?f=33&t=15150&start=0
http://www.tamiyaclub.com/forum/index.php?showtopic=50728

Pictures
http://www.rctech.net/forum/attachments/electric-off-road/435889d1238565067-kyosho-ultima-rb5-thread-dsc02070.jpg
http://www.tamiyaclub.com/forum/index.php?app=core&module=attach&section=attach&attach_rel_module=post&attach_id=7598

Manual Exploded view
http://www.cls.eclipse.co.uk/RCCars/RB5%20New%20Shafts.jpg

Discussions
http://www.rctech.net/forum/electric-off-road/147740-kyosho-ultima-rb5-thread-415.html
http://www.oople.com/forums/showthread.php?t=30135

optiman

26-02-2013, 05:42 PM

Well, to be honest I use the truck for maybe two days of testing. I got so frustrated with it that ditched the whole project very soon. I spend a few hours on design and fabrication and when I got the final result I was quite depressed :( But it was a learning expirience, and it was the best and easiest RC car I had to drive, with the exception of the jumps and from standstill acceleration. The truck was basically made with a Duratrax Evader St donor truck. They are basically Losi parts, A arms, braces almost everything are the same and interchangeable.

You know, now that I think of it, I have a Hybrid stadium truck made from a B44 chassis and T4 parts. The motor is mid positioned and batteries are already on the back. I am going to remove the rear drive shaft and see what happens :thumbsup:

Here is a drawing I found of that project I made and pics of the BT4 hybrid truck

Typpo

26-02-2013, 05:46 PM

I had a look at the Xray XB4 CVDs, however, they are actually shorter than the Tamiyas (strange being that they actually say '68mm'), and the head that goes in the outdrive has too big a diameter to fit. So, TRF201 Driveshafts it is!
:D
After reading your more recent posts, you may find the following measurements helpful. Using the labels shown at the link below:

http://www.rc10talk.com/download/file.php?id=67892&mode=view

Some corresponding approximate measurements in millimeters are listed here. Where ball diameter is the "head that goes in the outdrive"

Kyosho LA231-01 (A=9.75 B=68 J=2.0 with ball diameter 5.89 and axle cross pin used 2.0mm)
Schumacher U1915 (A=11.8 B=68 J=2.5)
Schumacher U2683 (A=11.8 B=70 J=2.5 with ball diameter 6.96 and axle cross pin used 1.5mm)

Unmeasured
XRAY 365320 with106051(according to manufacturer specification listed A=12 B=68 J=3.0)

Also I think the wheels used for the Kyosho and Schumacher axles listed, have 4mm hole diameters while the Xray and the Team Durango rear wheels may have 5mm diameter holes. Perhaps someone can verify this.

smokes

26-02-2013, 06:09 PM

Would a Double cardan joint be suitable for this application so you get a linear rotational speed what ever the angle?

Origineelreclamebord

27-02-2013, 06:57 AM

Wow, what a response guys! :o

@Typpo: That amount of info on the Kyosho CVDs is very interesting, thanks for sharing! :thumbsup: I will do some comparison work in Photoshop between different pictures and what shows potential will be sourced.

I did find a slightly better option in the meantime than the Tamiya CVDs, being Tamiya's Universal Shaft wheel axles (not WO Universal/CVD) with the 65mm Durango DEX210 bones. It fits as if Durango copied the geometry of Tamiya's U-joints :lol: Ok, Tamiya's '64mm' shafts actually seem to be 64.5mm, so I only gain 1mm of width, but it is still 1mm wider, plus, the outdrive pins now have the perfect diameter.

Nonetheless, my search continues. There is room for improvement, hence no reason to stop searching!

PS: I'll also share the pictures of the Xray XB4 vs. Tamiya 201 CVDs to show you why the Xray axles are interesting and the bones are not suitable for my project.

@optiman: Nice B44 truck! My guess is that that car too will have some acceleration issues with only front wheel drive, but it's an easy and fun test :) Every time a 4WD buggy's drive on the rear breaks down I'm closely monitoring how it gets around the track, and to be honest for something that just happens on the spot they do pretty well :lol:

@smokes: A double cardan shaft may work very well - in fact, there are so many 'constant velocity' solutions out there that are interesting to have a look at... I'd love to make a Rzeppa joint for an RC car (the one in the center):

http://www.kurtisfranklin.com/blog/wp-content/uploads/2012/09/U-JOINT-RZEPPA-BIRFIELD-BENDIX.jpg

This does require too much customizing or even machining from scratch. Even the D-joint from Durango is a bit complicated to work with for now, but these things are worth thinking about (especially the double cardan joint because the availability of the D-joint or putting two CVD systems together) :thumbsup:

ekt

28-02-2013, 01:21 PM

TD have recently released longer ball diff outdrives if that would help you #TD310417

Origineelreclamebord

28-02-2013, 01:27 PM

TD have recently released longer ball diff outdrives if that would help you #TD310417

Do you happen to know how much longer they are? :eh?: Because it sounds like just the thing I need - thanks for letting me know :thumbsup:

ekt

01-03-2013, 08:38 AM

Sorry, wouldn't have a clue how much longer they are :(

smokes

01-03-2013, 01:06 PM

Origineelreclamebord

09-03-2013, 08:22 AM

Thanks for the replies guys :)

@ekt: I emailed TD but they didn't respond... Since I will be picking up this project again after a few deadlines from school I thought I'd just order them. After all I can always shorten them if they're way too long :lol:

@smokes: The Litemodz shafts look awesome! :thumbsup: I might email them to ask if any of those sets might be compatible for a TRF417... So I could actually try them out! :p

I also noticed that RDRP has released 'RR' suspension hangers (the ones I use for the front suspension) with different kickup settings. Sweet! :thumbsup: That means the kickup it now adjustable from -3 to 3 degrees - if needed (with a 'kit' setting of 0).

mrspeedy

09-03-2013, 07:07 PM

I'm pretty sure the std RR hangers could be shimmed up with washers anyway to give you some kickup ... thats how we adjust the FR hanger for antisquat ...

Origineelreclamebord

13-03-2013, 11:56 PM

I'm not sure it is possible on this car - without raising the gearbox. Not to worry though, the first proto seemed better off with less anti-squat/kickup, so this neutral setting should work nicely.

Anyway, I've got an update on the car again :)

http://i65.photobucket.com/albums/h212/Varockshade/AC210FF%20Project/Screenshot18.jpg

So what's new?

- I (finally!) finished the rear shock tower and wing mount setup. I'm not 100% happy with the shock tower mount block, but it's the best I have done after some 4-5 retries at this and more than a month of thinking about it. I do really like the wing mount: The wing elegantly floats on two small mounts that attach to the single vertical plate that runs to the center of the chassis. It doesn't just hold the wing, it reinforces the shock tower too.
- The chassis has gotten another 15mm longer. This is to allow ever more space for the electronics, and at the same time shorten the rear arms. Less unsprung weight of course, but also, if the arms break - or an updated version is needed - they cost a bit less to replace.
- New front suspension arms. These are made to twist less because there is more distance on the narrowest point of the suspension arm. Also, the shock is moved a little to the back to allow a brace to pass in front of it. I also beefed up the arms around the suspension shafts - they are now 9mm around there instead of 8mm. I plan to do the same on the rear arms, but they're not finished yet. The front arms also have more room at the front hub, so the plastic DEX410R hubs (that have the grub screw in a different place) also fit on the car.
- Updated bottom chassis plate. Based on what I rear on breakage on the DEX210 of carbon and moulded plastic chassis around the holes for the suspension blocks, the chassis plate is 1mm wider on each side at the gearbox part - it doesn't sit in the way of the suspension, so why not reinforce it? Lastly, the part where the chassis gets wider at the front is angles further backwards (less 'square') - this is to allow more clearance between the tires and chassis on full steering lock.
- New front bumper. This one is angled more up to reduce the chances of it snagging on something or digging in - with some playing around on the geometry I also managed to keep the same amount of flex (=protection) on the front end.
- Shorter wheelbase. The wheelbase was ridiculously long (285mm), and I decided to shorten it a bit and give it +0.5 degree toe-in. I'm expecting it will need the added toe-in for stability with the narrower tires, but of course I'll only find out once I have the car up and running.

Edit:
A brief look at donor bodyshells:
http://www.oople.com/forums/[IMG]http://i65.photobucket.com/albums/h212/Varockshade/AC210FF%20Project/Screenshot19.jpghttp://i65.photobucket.com/albums/h212/Varockshade/AC210FF%20Project/Screenshot19.jpg

The Schumacher K1 bodyshell seems to have a very suitable chassis profile. There is just one problem - for all existing bodyshells - on my car. The sidepods need to be much higher than usual. I might be able to achieve this with bodyshells that are not pre-cut (unlike the K1's body). So I need to find out if there's an aftermarket alternative yet for this car, or...

...I rotate the servo 180 degrees and put the steering linkage in the center of the car. This does mean no big electronics fit on the top deck anymore - and I'll make a small mount to neatly guide the motor wires. It does mean that I can run many more bodies on there (butchered or nearly standard), a good thing for the earlier stage of the project. A bit like this:
http://i65.photobucket.com/albums/h212/Varockshade/AC210FF%20Project/Screenshot20.jpg

I do realize that the cab will be in an awkward spot on the car :lol: It's definetely not definitive what body I'll use, but I'm throwing it out here anyway what my findings are so far :)

mrspeedy

14-03-2013, 02:12 PM

Sorry I really don't mean to pick holes cos I think you're doing a fanatsitc job ...

The rear suspension .. its slopes the wrong way ... surely it should angle upwards towards the front of the car, this should make it handle bumps better and squat less on power ... I'd also lay the rear shocks down as much as possible to give minimal weight transfer under power ..

Just my thoughts :)

Origineelreclamebord

14-03-2013, 05:00 PM

Hehe don't worry about it, all advice to possibly make the car go faster is welcome :thumbsup:

To clarify what you're pointing out, do you mean looking on it from the side view, the arms should be horizontal, not sloped like they are now? Or do you mean when looking from the top view, the angle of the hinges should be changed? Or... Is my brain failing me and am I way off from what you mean? (It wouldn't be the first time it'd happen to me) :lol:

I'd love to make the shocks lay down more. In fact, I'd love to make gullwing arms. I'm not doing that because a symmetrical design is handy though in the prototyping stage - you need two types of arms in the spares box, not four. Laying down the shocks further results in a bit of trouble with the spring retainer at the bottom, they will interfere.

There are multiple solutions to this: using different rear shocks (no DEX210 front ones, but TRF201 front ones - small bore, and more importantly, 10mm shorter). I'd like to keep the same shocks all around though. Another solution is to use an insert piece that holds the shock that mounts the damper what would normally be below the rear arm. The part can be reversed to mount the arm on both sides, whilst also allowing a low mounting. I'll have to think about these options for a bit, they all have their pros and cons :)

RC-trix

14-03-2013, 05:08 PM

Nice job, Paul
Just don't be tempted into using the K1 body :lol:

Why not go all the way and get your own shell vac-formed-if you make your own mould, it's not that expensive.

Steven

Origineelreclamebord

14-03-2013, 06:27 PM

Nice job, Paul
Just don't be tempted into using the K1 body :lol:

Why not go all the way and get your own shell vac-formed-if you make your own mould, it's not that expensive.

Steven

Thanks! :) and another thanks for confirming that about the K1 shell :lol: I'm not usually a fan of cab forward bodies (though somehow I don't find the K1's body that bad - on the K1), but once I saw in Photoshop where that cab would be I was having my doubts.

As for vaccuum forming, it's not so much costs (there's even a vacuum forming machine at school, the only question being if that machine has the right surface area for a buggy body). It's the time it takes to make a proper mould. I talked with Bugle about some experiments with Polyurethane foam for a bodyshell a while back. I haven't found the time yet to actually try it out, but the idea is to put a hard, heat resistant coating on the PU foam and see if it is durable enough for vacuum forming. If it is, it means I have solved the 'time' issue, a pretty nice PU foam model can be made in as little as 8 hours :)

mrspeedy

14-03-2013, 06:35 PM

Sorry I'm not being very clear ..

Typical FF buggies below, pretty sure you will have seen these before, but they all have the rear wishbones setup with a good degree if anti-squat, which must help with reducing weight transfer under power and also allow the rear end to run better over bumps ..

Most of these also have the rear shocks laid down using a small standoff on the arm to raise the lower shock mount, I'm no engineer but most of what they did looks like it made sense, particularly the HPI version with its raised rear wishbone mount ... also looks the dogs doo da's to me :woot:

http://i137.photobucket.com/albums/q207/piktophoto/FF-2.jpg

RC-trix

14-03-2013, 07:42 PM

Origineelreclamebord

14-03-2013, 08:05 PM

Thanks, I didn't look at it like that yet! :o Nice!

The height of the rear suspension hinges is already a bit adjustable on my car - the outer blocks can move freely up and down when spacers are used. The inside can move up to 2mm up. My plan was to try out different angles on the arms by spacing the outer ones further up than the inner one (or the other way around).

I think with a few small mods I can increase the clearance for the inside suspension block to move up by about 12mm - that should allow a lot of adjustment to find out how much of an effect it has on performance :) Though with 12mm of spacing the blocks might need some braces over the top (connecting to the chassis plate elsewhere) to keep the chassis plate in good condition.

By the way, what I did notice on the first proto is that the stance mattered a lot to the car. Raising the back end really made the car much more responsive and agressive. I'm not sure whether that's down to the anti-squat effect you described or the stance, but the stance as you see it in the SolidWorks model is not likely how it will be in practice (perhaps on high bite carpet, but otherwise certainly not) :)

Origineelreclamebord

15-03-2013, 08:34 AM

Paul, a while back I had the chance to visit a professional vac-forming facility (in the Netherlands), and for low-volume work, they use plywood moulds with a few aeration holes.

They gave me a quote back then of about 50-80€ for a one fifth body.

I'm assuming that is when you supply the mould? :confused: If that inc. making the mould then I'm really interested, as a nice wooden mould still takes quite a bit of effort to make and machining services don't come cheap usually :p

Edit: I've spoken to the someone in the workshop at the university, and he expects that as long as it's coated, the PU foam should hold nicely. I also found a company who states on their website they often use PU foam (CNC machined) for their vacuum forming moulds. So now I'm on the lookout to find a nice coating for it that doesn't melt or become sticky and soft when the polycarbonate is pulled over the mould.

RC-trix

15-03-2013, 10:17 AM

Thats if I supplied the mould - but there may be less labour-intensive ways to make a mould, one of the employees was into RC and he had made ABS copies of a Tamiya body taking a cast.

Their site http://www.heku.nl/het-proces/vacuumvormen

mrspeedy

15-03-2013, 01:53 PM

If you can get the mould lazer cut then MDF works just fine, its how we make most of our prototype work now ... its fine for one off's but the quality is not up to scratch for large quantities or for retail ...

Origineelreclamebord

16-03-2013, 12:17 AM

A mould/custom shell I will consider, it doesn't just look cool, it allows a good, tight seal of the chassis - something the previous car lacked. And I admit it, I'd love to make the car look good! I pulled out one of the many designs I made for an FF Buggy bodyshell from the archives and decided to try and make the design work for this chassis. The result:

http://i65.photobucket.com/albums/h212/Varockshade/AC210FF%20Project/Screenshot21-1.jpg

I'm very happy with how it turned out :) I experimented a bit with the servo/steering layout on the car. It's now possible to swap the servo from left to right to move the steering linkage between two settings: the center of the chassis or near the edge of the chassis. I don't plan to run more than a receiver or PT on the top plate, so I'll run the linkage in the center of the chassis.

Why is this relevant? Well, running the steering linkage down the center allows a much lower profile bodyshell. The sidepods are up to 10mm lower, and the cab is, too. It did need a higher piece up front because of the steering rack, and a protruding piece on the right side for the servo horn.

Gayo

16-03-2013, 10:43 AM

Man, your project is so cool! Kudos :thumbsup:
Loving your shell design:)

RC-trix

16-03-2013, 07:58 PM

Muuuuuuch better than the hacked K1

ruf

17-03-2013, 09:26 AM

Origineelreclamebord

17-03-2013, 01:23 PM

Thanks guys, I'm glad you like the shell :) I've got tons more designs, but many aren't even do-able with a plate+post chassis design :p

@ruf: I've never seen these before, but I really like what I'm seeing :thumbsup: I can imagine the load on that system is much better distributed around the head of the dogbone and on the outdrive - and it should be pretty smooth (though on a tourer I can't see much benefit of that on the outdrive end, as the suspension barely moves).

For now I'll keep it at existing driveshafts. When the FF shows potential to make rear wheel drive eat it's heart out (without being banned from the 2WD class of course), I'll definetely look into 'alternative' driveshafts. A good place to start would be to test the different settings on a touring car chassis, Double Cardan and even Rzeppa Joints are already available for some 4WD tourers :) It shouldn't prove that hard to convert these systems onto a FWD tourer as long as the driveshaft fits in the outdrive.

TryHard

17-03-2013, 01:41 PM

For Driveshafts... LiteModz used to make a proper scale CVD for RC... not sure if the company exists anymore though..

http://www.redrc.net/2010/07/litemodz-cvs-constant-velocity-driveshaft/

mattr

17-03-2013, 02:52 PM

Those sort of joints don't like large angles and lots of off axis torque.
We have a good number of problems with them during development in 1:1 applications.

Origineelreclamebord

17-03-2013, 08:01 PM

@TryHard: Last week their website worked just fine, but today it seemed offline. I sure hope it's just a problem they're having with the website, not with their business. I liked the CVS Driveshafts, and I quite liked the pictures I saw of their touring car... :)

@mattr: Could you tell me more about this? :) What you mean with off axis torque (plus, what the result of this phenomenon is on handling, durability etc), what angles you can use it at all, and without off axis torque problems, what other issues you might be facing and lastly, if there are any solutions to this that you could share with us?

mattr

17-03-2013, 08:37 PM

Origineelreclamebord

17-03-2013, 09:41 PM

When you get to higher angles, the balls on the outside/inside of the bend come out of their groove, or at least, don't engage enough to transmit any torque with out damaging the balls/grooves. You end up transmitting the torque thro the balls to the left and right of the bend. Concentrating the load.
Also, all the shuttling in and out wears the balls/grooves very quickly. We have to use special, modified CVDs for XC type vehicles, at huge expense. Not sure exactly what the threshold is, but 18 degrees is sounding alarm bells.

Wow, that sounds really troublesome! :( I really thought they could handle more than those 18 degrees and were more consistent (though I did read about raised wear levels).

Still, I'm interested to give them a shot later on in the project - in fact, I'm open to a lot of suggestions on this one. Jimmy mentioned he seemed to have a bit more traction with his Tamiya DB01 using dogbones rather than universal shafts. I find it surprising (I'd say upgraded parts should enhance handling), but I don't doubt his judgement. It's worth trying :thumbsup: The same counts for Rzeppa joints (if possible), CVDs (both the type with the cup on the axle and the type with the cup on the dogbone), and something I'd fancy to investigate further is rubber driveshaft couplings like the Lotus Elan have from the factory. A simple mechanical solution, I believe it's a constant velocity solution, it offers some give in the drivetrain (VERY desirable on a front wheel driven car I'd say, even if this makes the feel of the throttle a bit more vague and slingshot-like).

ruf

18-03-2013, 12:54 AM

Jimmy mentioned he seemed to have a bit more traction with his Tamiya DB01 using dogbones rather than universal shafts. I find it surprising (I'd say upgraded parts should enhance handling), but I don't doubt his judgement. It's worth trying :thumbsup: This is a known phenomenon in offroad RWD. CVA, CVD, universals, sliders, and dogbones all have different effect on rear traction as the mating surfaces interfere with suspension travel under load, and thus affect weight transfer. In addition, the angle also plays a large role, hence the idea of spacing the gearbox higher. Also fore/aft angle has an effect, especially notable in touring cars as the front arm/caster block is spaced back and forth. Wheelbase is only part of it. :)

mattr

18-03-2013, 07:18 AM

Wow, that sounds really troublesome! :( I really thought they could handle more than those 18 degrees and were more consistent (though I did read about raised wear levels).It may well be more than 18, i was only involved very vaguely as it's not my area of responsibility. I do know that different designs behave differently (greater or lesser angles possible) but that one looks very simple, so likely to have a lower angle before "issues" occur.

Origineelreclamebord

18-03-2013, 06:57 PM

All in all the science of these driveshafts is pretty complicated - which makes it all the more interesting! :thumbsup:

I really appreciate all the ideas, suggestions and information coming in! All this input (in general, not just he driveshafts) has really helped to develop the car more quickly and find potential ways to make the car perform better before it even hits the ground :) And it also gives points for improvement for the longer term.

Speaking of such things, I've updated the rear shock tower and done the rear arms:

http://i65.photobucket.com/albums/h212/Varockshade/AC210FF%20Project/Screenshot23.jpg

Gullwing arms were not an option, so I did what I think is the next best thing: Mounts below the arms. You might wonder how these arms could be symmetrical... Well, the idea is to print the arms with mounts on both the top and bottom side, and remove the side you don't need with a Dremel. That way the car uses 'directional' arms, yet if you grab one from the spares box it will fit on either side of the car (even though it may not look as pretty for the rest of the race day) :lol:

To lower the dampers through the suspension arms, the arm requires a huge opening in the center. I think it will hold just fine, but I guess I'll find out exactly how strong it is on the track. Durability concerns aside, the change allows for a much lower shock tower assembly without using very radical angles on there. It also allows the wing mount to move 5mm further forward and to use smaller clearance cutouts in the wing.

It's another thing off the list... In fact, I'm now kind of waiting for the long outdrives to find out if the car will become 240mm wide or slightly wider :)

Origineelreclamebord

28-03-2013, 07:14 AM

Ok, time for a little update :) The long outdrives got in (link (http://www.oople.com/forums/showthread.php?t=125130)) - they are 1.25mm longer, and apparently the gear diff outdrives too are longer than the original 210 outdrives.

Conclusion: The car can become just a bit wider. I made it wider by 0.5mm each side - it means a safe clearance of the diff nut, and the extra distance I'm using - like Durango intended with these outdrives - to keep the driveshafts properly seated on extreme angles (and I'll have plenty of those situations in store for this car) :lol:

I tweaked the suspension stroke on the rear (it was too much compared to the front). I also made a few spacers here and there in specific shapes so when it's taken apart you can distinguish parts and you're not shimming until the world ends!

All these spacers and small bits have been ordered at a 3D printing company (I needed parts for another project) - the big(ger) parts from the car itself will be printed soon as well, and the plates will be cut from Plexiglas first (I suppose that'll do it for road testing).

If the mockup and onroad test drive shows no problems, then the car is converted straight to carbon and 3D printed nylon :thumbsup:

As a last thing... I decided to stick with Big Bore shocks. I was planning to use SB shocks with BB springs, but it's too expensive right now to buy two sets of front SB dampers (the cheap spot I sourced - where both SB and BB dampers are less than 30 GBP new, also had only one SB set in stock).

I may need some time to understand the BB shocks as I've never worked with them, but I'm sure they will work nicely. In later testing stages I could always consider moving to SB shocks with BB springs.

Origineelreclamebord

30-03-2013, 04:55 PM

I was in the mood to make some fancy pictures today :)

http://i65.photobucket.com/albums/h212/Varockshade/AC210FF%20Project/Render1JPG.jpg

http://i65.photobucket.com/albums/h212/Varockshade/AC210FF%20Project/Render2JPG.jpg

http://i65.photobucket.com/albums/h212/Varockshade/AC210FF%20Project/Render3JPG.jpg

http://i65.photobucket.com/albums/h212/Varockshade/AC210FF%20Project/Render4JPG.jpg

http://i65.photobucket.com/albums/h212/Varockshade/AC210FF%20Project/Render5JPG.jpg

This is what the car could end up looking like :) This result is still a few steps away (particularly the body) but everything has been going quicker than expected on this second prototype. I can only hope the car itself also goes quicker than expected! :lol:

RC-trix

30-03-2013, 06:16 PM

Pro-quality work, Paul

Origineelreclamebord

22-04-2013, 10:44 PM

The design work is up to the point where the parts for the second prototype can be made - the files have been sent to the parts making parties :) I can't say how much time there will be between now and receiving the parts, but fingers crossed it's soon!

What I can share with you in the meantime is an image to show you how extensive the conversion is:

http://i65.photobucket.com/albums/h212/Varockshade/AC210FF%20Project/Screenshot27.jpg

As you can see the car only has a donor gearbox, driveshafts, hubs, shocks and rear axles.

I'm currently working on getting all donor parts ready. The gearbox has a minor issue (the layshaft spacer seems to bind up the gearbox a bit), other than that it's going pretty well. The shocks are built and ready, I'll be making a setup sheet for the car soon for the first setup I'll be trying.

johnnygibbon

23-04-2013, 07:49 PM

looks amazing quality
ive been puzzeled about your gearbox issues . wish i could help

Origineelreclamebord

25-04-2013, 08:37 PM

Thanks :D I think the gearbox issue is just a spacer that's a wee bit too long - it is the layshaft that's causing the trouble, and it seems to happen only when I tighten the stuff and have all the parts in there: without the layshaft bearing (closest to the motor plate) in there it went just fine - probably because that means nothing could bind :p

Anyway, I got a bit bored of waiting for the parts after the amount of time I've spent on the project, so I kind of had to make something... Why not make a setup sheet for the car?

http://i65.photobucket.com/albums/h212/Varockshade/AC210FF%20Project/SETUPSHEETAC210FFJPG.jpg

It immediately gives a good overview of the setup options. I think it's fun to see how much the front can be adjusted as opposed to the rear end :) It's funny looking back on it how little I did with those setup options on the last car, all because I was focusing on tires and the issues with that inboard shock system.

PS: Next time I will make the setup sheet in a different way... it took way too much time to make!

tramp

26-04-2013, 07:29 AM

Thanks for the update, im really enjoying this thread & cant wait to see the finished product. It's great how professional this all seems! Seen as though you have all the CAD/CAM data will you be getting more components manufactured to be sold as a kit? it would be great to think that regular people who dont have the same CAD skills could own their own front wheel drive

Origineelreclamebord

27-04-2013, 09:50 PM

Sorry, double post...

Origineelreclamebord

27-04-2013, 10:15 PM

Thanks, I'm glad you like it! :thumbsup:

The CAD/CAM modelling I find flexible to adjustments, and it's the portal to many manufacturing processes (such as 3D printing).

I'd love to get components manufactured to sell conversion kits, no doubt :) However, currently that's getting a bit ahead of things: Until I have actually built the second prototype and driven it a couple of times, I can't judge the status or in what stage of the project I am.

That's one of the reasons why I'm really eager to get the parts in and get the testing going a.s.a.p, but I can't make predications as to when that happens as I'm not in control of the manufacturing processes. Another reason is that I have set goals to drive the car on certain events.

Origineelreclamebord

04-05-2013, 10:39 AM

http://i65.photobucket.com/albums/h212/Varockshade/AC210FF%20Project/SETUPSHEETAC210FFFilledInJPG.jpg

I just noticed I'm missing a box to fill in the weight of the car, but... It's filled in! :lol: This is the setup I plan to use to test the car for the first time - unless it looks/feels really awkward on the pit table of course.

The main areas of focus are mentioned on the sheet. With one or two tests I'll find out soon enough whether my estimations on oil and springs are any good, whether I need the 'extra' degree of toe-in on the rear (compared to RWDs) and if a 4-rib tire has enough bite to keep the rear end from sliding out on corner entry. Also, I'm expecting the 4-gear setup to be quicker, but being familiar with the 3-gear setup already I see this as the best starting point.

These things are essential to determine for the car, and for a variety of surfaces: It's not guaranteed I'd want to drive either 3-gear or 4-gear all the time.

I'm really looking forward to checking the box on finding these big setup changes and starting to play around with all those spacers and the roll center of the car :drool: It feels a bit funny thinking of the setup for the car when the parts aren't even here yet, but let's hit the ground running when those parts arrive! :p