TRF201 Carbon Shock Tower

[Origineelreclamebord]

Hi everyone,

I was thinking about making this:


A carbon front shock tower The stock one is nice, but I did break about 3 of them last season - some unlucky incidents, but I see room to reinforce those 'braces' in the middle - those are the pieces that seem to break.

Also, I'm looking to get a bit more flex of the shock tower to prevent the front bulkhead from damaging - particularly indoors it gets too much of a beating. I could increase the flex with a glass/carbon combination plate, a thinner plate, or by putting O-rings in front of and behind the assembly when screwed onto the bulkhead.

The geometry at the moment is nearly the same: The shock holes are in the same spot, the turnbuckle mounts are 1mm further to the front to make the mounts symmetrical, but everything is the same otherwise

[clint]

I am in!!! have been wanting these for a long time now but nobody makes them..
What thickness were you thinking? I would be in for a few in 4mm..
PLEASE DO IT..

[Origineelreclamebord]

Haha thanks! I was thinking of 4mm carbon - or 3.5 for slightly more flex, but 4mm seems the standard for durable towers

The turnbuckle mounts will be 3D printed - at first anyway. Even though I'm pretty confident the 3D printed nylon will hold - unless maybe it is crushed on a hard trackside object (poles, edges of barriers, etc). I've also made suspension blocks and hubs from the material that held just fine.

I'll order one or two plates for myself soon, plus 1-2 pairs of blocks/mounts - I hope to be able to test it in 3-4 weeks time. If there are no major issues I'll put it on sale a.s.a.p

[ruf]

I'd look into anodized aluminum for the turnbuckle mounts. It will be a lot more cost effective than 3D printing in the long run, and if you design it symmetrically, you can effectively halve your minimum order quantity. In addition, the Tamiya crowd tends to be particularly fond of light blue anodization which would greatly increase the marketability of the product. Just my $0.02.

[Origineelreclamebord]

Originally Posted by ruf

I'd look into anodized aluminum for the turnbuckle mounts. It will be a lot more cost effective than 3D printing in the long run, and if you design it symmetrically, you can effectively halve your minimum order quantity. In addition, the Tamiya crowd tends to be particularly fond of light blue anodization which would greatly increase the marketability of the product. Just my $0.02.

Hehe, anodized aluminium would look awesome indeed The 3D printing is not very marketable currently because many people don't believe it can be strong enough, so to make it sell well it needs to be aluminium (even if in actual functionality it wouldn't matter much - or at all).

The only problem to manufacturing these shock towers is that I can't afford the investment to stock a good load of them (which is what makes any of the manufacturing options cheap).

[ruf]

Originally Posted by Origineelreclamebord

Hehe, anodized aluminium would look awesome indeed The 3D printing is not very marketable currently because many people don't believe it can be strong enough, so to make it sell well it needs to be aluminium (even if in actual functionality it wouldn't matter much - or at all).

The only problem to manufacturing these shock towers is that I can't afford the investment to stock a good load of them (which is what makes any of the manufacturing options cheap).

MOQ investment will always be an issue with manufacturing. I think that with a 2:1 ratio of the turnbuckle mounts, you might find that the aluminum parts will be cheaper on your BOM than the carbon fiber, especially at the thicknesses you're talking about.

[Origineelreclamebord]

You may be right, but it'd be a big financial risk for me I'm a student, I can design the stuff but stocking the stuff is an issue - especially on a car with relatively low demand like the TRF.

Regardless of that though, I'll follow through with the development of this. I've got two towers in 4.0mm CSC (Carbon outer layers, glass (Silica) inners layers) on my way and I'll be ordering the 3D printed parts before the weekend along with some other stuff. Stuff like this:


New thumb screws. The standard thumb screws don't have a lot of hold on the grub screws with 25mm LiPos (Turnigy Shorty packs)+Rudebits Under LiPo weights. These thumb screws should solve that, and with the slightly larger diameter (+2mm) and rougher profile should grip a bit better too. They cost me less than 1GP to print if I exclude postage from the equation... money well spent on details that make the car feel better!

Anyway, back on topic. With a bit of luck these parts will be in before the 4th of april. If that's the case, I'll be able to test it right away in my first Dutch/Belgian 'Nationals' race It will be at the indoor track in Charleroi, Belgium - I heard it's pretty unforgiving to bad landings, so this tower design will have to work hard to prove itself!

[Origineelreclamebord]

I was very surprised to these were already in today! Fibre-Lyte did an awesome job, the parts are spot on and look the part imo!

As you can see, the tower has the same geometry but is a lot narrower. This should allow to fit BB shocks (or SB shocks with BB springs) a little easier, in particular on the inside mounts. Making it wider would also not add to the strength as the turnbuckle mounts are seperate parts.

The 3D printed parts have been ordered a few days back, so these should come in halfway/end next week.

[Origineelreclamebord]

So here it is, mounted to my car






The blocks are a bit more substantial in practice than they looked in the CAD files. All things considered, I quite like it. The look of it, the fact that this does flex a tiny bit whereas the original towers don't at all... and an unexpected side effect of the tower that it's low crosshatch in the center is a bit in the way of the body.

I trimmed it a tiny bit (+/- 3mm narrower lexan nose piece) and now the tower neatly holds the front of the body down without a body clip. Still, it's something I'll adress in the CAD file.

[clint]

Looks really good! I am curious to see how those camber link blocks hold up to some action.

[94eg!]

Originally Posted by clint

Looks really good! I am curious to see how those camber link blocks hold up to some action.

Why not simply design horizontal camber link holes into the carbon of the tower similar to this:



If placed correctly, you could still maintain the same geometry. I imagine 8mm long hard hex-head balls w/ a spacer on the front and a lock-nut on the back should clear the dampers perfectly.

[Origineelreclamebord]

Thanks for the suggestion!

I could get to the same geometry to the kit setting, but the adjustments of shimming can be smaller than on just a plate setup on which you mount the ball stud - and it will keep the way of setting up the same as on a stock TRF201. Both valid reasons to me to go for turnbuckle blocks

If one doesn't consider that a problem though, indeed a tower consisting of just a plate is sufficient. I guess I'll find out if/when I look for a supplier of the alu blocks if the question of costs is of much importance here, because that could be a determining factor.

[Origineelreclamebord]

It's been a while since I last posted anything about these parts, and I think it's time to update you on this little project







http://i65.photobucket.com/albums/h2...e/IMGP6845.jpg

http://i65.photobucket.com/albums/h2...e/IMGP6846.jpg

http://i65.photobucket.com/albums/h2...e/IMGP6848.jpg

http://i65.photobucket.com/albums/h2...e/IMGP6849.jpg

I've driven four events with the shock tower:
- BNK* Charleroi (Indoor Astroturf, quite unforgiving and quite an unforgiving track when it comes to damage to your car).
- EOS Dortmund (Carpet, very high speed, so any mistake results in hard hits).
- BNK* Kampenhout (Outdoor Astroturf, quick, flat track).
- Club Race Vlijmen (Outdoor Clay, quite mild and forgiving on the car).

*BNK is the 'National' championship of Belgium and the Netherlands combined.

So it's seen three and a bit race weekends, with two unforgiving tracks on which the car got a huge beating. The front shock tower held up well though: I'm still on my first set of printed blocks and the first plate. I did notice what seemed like hairline cracks on the outside layer of the tower just above the upper mounting holes of the tower to the chassis... but I'm not sure. As a precaution I dipped it in glue to prevent the cracks from growing if they were there. The 3D printed blocks show some dents, scratches and dirt but there are no cracks, the threads for the ball studs are still good and it's good to go for more racing

There are some small changes I'd make:
- Carbon material instead of CSC to add a little strength (CSC=Carbon outer layers with glass center layers).
- Slightly higher cross brace frame in the center of the tower (so the body doesn't need slight modding to fit).
- Give the 3D print blocks a chamfered edge on the outside (note the first picture, you'll see white chamfered spots - it is to allow full droop with the turnbuckles on the inside with thinner spacers than the kit setting).

These are all pretty small changes though, it works very well. Actually, I think it doesn't need aluminium blocks - As demand for the TRF201 (let alone aftermarket parts) is relatively low I will not be looking into making alu blocks. If there is demand though I can look into stocking the parts for the tower+printed blocks.