Losi XXX-SCT MID

[londonladliam]

Welcome tinkerers,
This is my first project. This is how it arose...firstly had a day off i was bored. being bored on my day of i went down to the local model shop (TJD MODELS) and was actually going to get some 3MM ply to mess around with but to the side i found fiberglass *WIN* so bought that instead came home and started...
I purchased a atomic carbon cr2 alloy chassis off ebay (4-5 months ago) as well as a PSI Mid gearbox with intention of rebuilding it didn't end up actually doing it but this got me thinking the CR2 is based upon the XXX losi platform which is: XXX-T,XXX CR XXX BK etc.so id intentionally wanted to make a mid stadium buggy. But then with all this craze of late i started to look at the xxx sct low and be hold it was also based on the xxx platform. so i set about making a mid XXX-SCTsct using the atomic style chassis.
I purchased an XXX SCT chassis as this would be were i would get all my measurements from(i say measurement didn't measure anything)my cr2 chassis and a piece of fiberglass. Treated my self to a shinny new drill bit and set about creating an XXX SCT MID.
As the CR2 chassis is narrower than that of the SCT i opted for a narrower piece of fiberglass. Firstly i found the centre of the CR2 chassis and the fiberglass




I then G clamp the chassis to the fibre glass with the middle likes lining up



Then loaded my shinny new drill (something nice about a new sharp drill bit) and proceed to drill the rear suspension mounting holes. I decided to drill threw the CR2 chassis as it was alloy would help as a guide and make sure holes were bang one. I drill all four and the 5th which is the shock tower mount.



I then got some 3MM nut and bolts and placed four in the hole that i had drilled and nipped them up by hand to secure the chassis to the F-glass and set about drilling some of the other holes.



I then secure the CR2 Chassis the underside of the SCT chassis using the 3MM bolt and drill 2 of the battery support holes into the SCT.this was so that when i eventually bolt the SCT chassis to the piece of F-glass it would enable me to put two bolts in it to make use its dead straight and in line.




Now that i new the chassis's were all light up i was able to set about drilling the holes were the XXX-NT bulk head would bolt up to. Firstly i the hole sizes on the inner holes were a 2.5mm so i drilled the threw before hand to make sure the drill will pass threw clean when i went to drill threw into the F-glass.



once this was done i unbolted the chassis's from each other, and re-drilled the 2.5mm hole out to 3mm. Once this was done i then reattached the CR2 chassis on the lower of the bulk head mounting holes with the 3mm bolts. This would then enable me to get the upper ones in the correct position. I also made sure the chassis's was still inline by using the lines id marked on it earlyer.




Once this was done i drilled the upper holes i drew around the chassis with a pen as i would need to see the contours, being as the SCT is a much longer vehicle i would need to change the side are from what the original CR2 would have had. From where the lines intersect near the 3 holes down on the alloy CR2 chassis i traced a line straight up to the edge outline at the end (red line on image)this would then give me the shaped required for my chassis.



Leaving the chassis bolted together i set about making my first cuts. I used a band saw as they generally give a nice straight cut. I the picture you can see the red lines that were cut and far they were cut.i also did the cuts that run the length of the side pod, for the advantage of leaving chassis attached as it act some what as a guide i did this to the end of the side pod then stopped.with the atomic the middle are is cut away so i drilled a series of holes to help get rid of the excess latter.



next i unbolted the two chassis and set about doing the arced side cuts. I did this again with the bad saw i went in straight so that i just went past the are were the front bulk head would go(see red line on pic)did this for both side and took this cut up to the precious cut (green line)these excess side area fell away. I next then ran a cut across were the front were the bulk head will go and squared of the end (see turquoise line) with the ends square this leaves me less shaping later on. I then made two straight incisions (yellow lines)then cut the purple line using a fret saw. this left me with front end of the chassis practically done.



i set about doing the rear end so i bolted the alloy chassis back onto the F-glass in the rear most positin. I then used a junior hack saw to follow the shallow arc at the rear of the side pods i to this right the way down to the bottom so that it intersected the earlier cut. once the piece of material is removed then set about filling it all level. I used a flat and round one to take away excess fiber glass and filled till the i just hit the alloy. This was done on both sides. also whilst the chassis was in the rear most position i all filled the side pods level and flat again using the alloy chassis as a guide.



once this was done both sides. i move the alloy chassis back to the front bolted it up, and clamped it in a vice and started to neaten up the rather squarish front end again i filled till and shaped it till it just started to touch the alloy.



i dummy fitted the XXX-NT bulkhead make sure it fits and holes line up (they doo)which is a relief.




this last pictures shows how different the chassis's are and how i have managed to go from one to another



this is a far as i got in my evening of tinker. Im now at the stage were i need to designt the side pods and drill a few more of the mounting holes. Im also slightly split wither to do a twin deck chassis or a atomic carbon style chassis.feed back/comments welcome stay tuned!

[fredswain]

Nice project. That's going to turn out very good. I'm about to build what I term vintage SCT. I'm building a Losi JRX-SCT from an old JRX truck complete with a modern day interpretation/adaptation of the 5 link rear suspension. I've been debating making it a mid motor. Ever since I got my CR2, I've been less than impressed with rear motor setups.

[londonladliam]

i managed to get a little more done to day and im at the point were i need to get some more cr2 parts and fiberglass.

first i got the pieces id cut off yesterday and laid them next to the new chassis id cut.



i then measured across roughly about 7/8 mm but kept it as parallel as i could with the chassis,i copied the correct contour from the alloy one,



i then began cutting them out with band saw. I needed 3 each sided to draw level with the XXX-NT bulk head plus one more to lock them all down. Again using the left over piece of fiberglass.



once one was cut i would then use the contour/arc that was left as the start of the new one



i then filed a half circle into each of them so they but up nicely against the bulkhead



using the holes drilled i rested each side plate against the bulkhead the poked a pencil threw the hole and moved the side plate across the tip of a pencil to creat a line,i would then find the middle of this line and this would be the correct place for the hole to go.i didnt this using the rearest most hole and did this to all three bits.




once all of the side bits were drilled i stacked them all and fasten them all together with the fronts of them resting on the bulkhead and the rears all held but a nut and bolt. I then put a block under the chassis and taped the 3 pieces together then to the chassis and drilled from the base of the chassis threw



once this was drilled i put the last nut and bolt it and did it up nice and tight. Now all three bits were in the correct position i could deal with the over hang were some bits were larger than others. i took the bulk of the excess of with a bench sander then put the piece in the vice and finished by hand with files and worke it till it was flush with the chassis, this was done both sides.



once i was happy with the sides i then removed the stacks of 4 away from the chassis but kept them bolt, this allowed me to tidy up the uneven ness that would be on the inside of the chassis, i did this again with the bench sander and was done both side.



and this is what it all looks like thus far.



nest step is to get a few more CR2 parts to copy and gets some more fibreglass.......after being so pleased with the progress thats been made,and being so excited with it, i whipped the front and rear end off my xxx-t (some hours later) to see how it would look feast....







kachow!

[coleman758]

Looks really cool pal, Although pretty long!

Are you running SCT wheels & shell ? or is it staying as a ST

[londonladliam]

That's the first thing that struck me was how long it was.even compare to a long wb cr2 this is like a narrow boat.I have just ordered some short coarse wheelsso they be installed soon.the reason is an st at the momemt was I used a xxx t mf as the donor vehicle.

[londonladliam]

update on the project looks more like a SC now...








many thanks

[scotty_big_flip]

Looking realy cool buddy. Cant wait to see the finishd product.

[Groomi]

Looking good!

How did you find cutting the FRP with a bandsaw? I've read many accounts of the blade getting clogged up. General consensus seems to be that you need either water cooling or to do it by hand (generating less heat), but your cuts look pretty neat and tidy.

[londonladliam]

Updateeeee

[rcjunky]

looks good, those PSI trannys are the ticket