MY's Full Custom Build
 

I started work on my own custom chassis design and build several months back. Initial ideas were to use:

1. Portal axles
2. Low and forward motor
3. Overdrive in the transmission
4. Angled skid for improved rear clearance and tipping point
5. Design/build the chassis and as many of its parts as possible
6. Prototype using 3D printing

I wanted to use AR45 axles from the SCX10 III as I liked the narrower width compared to Capra axles, and also the offset front pumpkin which would hopefully allow for the motor to be lower (also why I didn't go with TRX4 axles) .

Other components I planned for the build were:

1. Hobbywing Axe 2300kV system
2. 1.9 beadlocks (cheap from Amazon)
3. CI L'il Nova foams
4. Proline Krawler KX (Predator) or JConcepts Landmines
5. Protek 370TBL servo
6. Brass portal covers F/R and brass steering portal case
7. JConcepts Creep body

Since I had a full SCX10 III kit, I figured I would utilize the axles, links, shocks, and driveshafts and so set about laying out the ends of the chassis rails. The center is TBD depending on transmission/motor layout, but will utilize the standard Axial skid hole spacings for the links and mounting. I didn't want to use the two-speed transmission from the kit, and the gears didn't lend themselves to a custom trans either. Playing with gears that were readily available, and various transmission layouts/designs, I ended up with something that would be very close to the Vanquish VFD, so nix to my own design and ordered the VFD (gotta love Amain!).

This let me finish up my rail design, so off to the 3D printer with some carbon PETG for trial and error adjustments. Also designed and printed: VFD skid and mounts, servo/panhard mounts, chassis braces, body mounts, F/R bumpers, and boatsides. Three or four iterations of most of the parts (hard to fit up with the PETG rails being very flexible), and I was able to drive it around the yard a bit and verify all was working. Time to order some laser-cut aluminum rails - was much easier and about the same cost as buying aluminum stock and pattern routing/drilling them myself!

http://www.rccrawler.com/forum/membe...4646-68391.jpg
http://www.rccrawler.com/forum/membe...4646-68392.jpg

More to come ...

Re: MY's Full Custom Build
 

Started swapping over parts from the 3D printed rails to the aluminum ones.
I intentionally had the holes in the rails cut undersized so drilled them all out to 3mm.
Everything lined up - all braces, mounts, skid, bumpers are in place.

http://www.rccrawler.com/forum/membe...4646-68398.jpg
http://www.rccrawler.com/forum/membe...4646-68397.jpg
http://www.rccrawler.com/forum/membe...4646-68395.jpg
http://www.rccrawler.com/forum/membe...4646-68394.jpg

Now to add the transmission, axles, servo, etc.

Re: MY's Full Custom Build
 

Following this with much interest. The ubiquity of 3d printing sure has made fast prototyping like this so much more accessible.

Cheers,
Gable

Re: MY's Full Custom Build
 

Progress on swapping over the parts to the new rails - axles, driveline and electronics all installed. Had to make new front mounts for the VFD trans - the printed rails flexed out and down so the new mounts are narrower and have the mounting holes repositioned to match the frame. Also had to redo the front top brace/body mount to add more clearance to the spur gear cover since the trans essentially sits a little higher without the rail flex.

http://www.rccrawler.com/forum/membe...4646-68403.jpg
http://www.rccrawler.com/forum/membe...4646-68406.jpg
http://www.rccrawler.com/forum/membe...4646-68419.jpg
http://www.rccrawler.com/forum/membe...4646-68418.jpg

The front driveshaft is a tight fit and it just touches the spur gear cover when both shocks are fully compressed. There is plenty of clearance under articulation though.
http://www.rccrawler.com/forum/membe...4646-68407.jpg

Re: MY's Full Custom Build
 

Ride height looks pretty good - will stiffen the front just a bit as it sits at about 70% compression, rear is in the 50-60% range.

Links at static height
http://www.rccrawler.com/forum/membe...4646-68404.jpg
http://www.rccrawler.com/forum/membe...4646-68405.jpg

And at full compression - front matches the VFD skid pretty well, rears look like some higher clearance links are in the future as there is still plenty of room to get to the driveshaft height.
http://www.rccrawler.com/forum/membe...4646-68409.jpg
http://www.rccrawler.com/forum/membe...4646-68410.jpg

Re: MY's Full Custom Build
 

Body fitment and checking for clearances. The Creep body is listed as being a 12.3" wheelbase, but if the rear wheels are centered in their arches, the front wheels will hit the fenders at full lock; I moved the body back so they just clear. This requires moving the rear wheels back, and I lengthened the rear links 3-4mm on each end - could probably have used long Traxxas ends to do the same. This is all with the stock SCX10 III links. Wheelbase has ended up at 12.8".
http://www.rccrawler.com/forum/membe...4646-68411.jpg
http://www.rccrawler.com/forum/membe...4646-68420.jpg

Re: MY's Full Custom Build
 

Good looking project you have going here! Curious to see how the 10.3 axles work out for ya. The width of my Capra axles is a little much sometimes but I like the performance of having the servo on the axle.
I’ll be keeping an eye on this build for sure


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Re: MY's Full Custom Build
 

Following! [emoji1690]

I really do want to do a custom build one day. Maybe my next project will be a custom...who knows, anyway looking great so far!


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Re: MY's Full Custom Build
 

Thanks Fricker08. Yeah, I like the more direct response from the servo on axle, and also find my Capra to be a bit wide at times - TGH wheels would help with that. I wanted the low forward central motor position though so needed offset pumpkins. That left the AR45 or Vanquish axles as the only portal options. Will see how the AR45s hold up - could always splurge for the Vanquish down the road.

ScaleLifeNewbie - thanks, and hope you get to do your own custom build soon!

Re: MY's Full Custom Build
 

Working on adding an interior to the Creep body. The interior from the SCX10 III has the look I wanted - more realistic for a truck than something like the Capras. Of course the Creep is a lot narrower than the JLU, but trimming out the center section brought it down to the right width. Was a bit challenging to get the outside cuts correct and I over trimmed a bit, but at least it will keep from scraping the paint off the inside of the cab!
http://www.rccrawler.com/forum/membe...4646-68413.jpg

And painted up.
http://www.rccrawler.com/forum/membe...4646-68416.jpg
http://www.rccrawler.com/forum/membe...4646-68415.jpg

Re: MY's Full Custom Build
 

Adding some exterior elements - 3D printed a toolbox to fit up against the Creep's cab. Will wrap this with Hot Racing aluminum diamond plate. Made in two parts to better simulate an actual opening lid, and also to make it easier to cover and hide the ends of the diamond plate. There are bosses inside to align the lid and box, and to glue the lid in place. Glued the diamond plate with Goop used like a contact cement, then burnished where the edges meet with a steel rod to soften the corners and make the seams blend a bit better.
http://www.rccrawler.com/forum/membe...4646-68412.jpg
http://www.rccrawler.com/forum/membe...4646-68417.jpg

Re: MY's Full Custom Build
 

I’m not sure if I’m more impressed by the build or how well you explained everything. Well done!


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Re: MY's Full Custom Build
 

Nice work. I especially like the chassis rails, you did some things I have thought about if/when I ever get around to designing my own rails...the shock towers in particular. Definitely can tell some thought was put into everything.

Re: MY's Full Custom Build
 

Thanks - really appreciate your comments. I've left out a few 'gotcha' areas that I had to work around - figure I will add those later somewhere in case they help anyone using similar bits and pieces.

Re: MY's Full Custom Build
 

Thanks! Will see how it works out once I can get it on the rocks. For the shock towers, I made holes to fit two specific length of shocks when compressed - the SCX10 III stock shocks (lower set of holes), and TRX4 shocks (upper ones obviously). The holes are all the same distance from the lower shock mount when fully compressed, just at different angles. This keeps the axle/frame clearance limit the same, but allows changing the shock progressiveness and axle down travel by changing the shock inclination. Hope you get a chance to do your own design too!

Re: MY's Full Custom Build
 

Finished with painting and adding accessories. I cut stencils for the door emblems and various text areas - dark gunmetal (darker than I was expecting) with silver for the emblems and text. Used the stickers included with the Creep body for the grill/front lights/door handles - need to find some for taillights and waiting to receive my RCPlateShop plates (probably here Saturday).
http://www.rccrawler.com/forum/membe...4646-68422.jpg
http://www.rccrawler.com/forum/membe...4646-68437.png
http://www.rccrawler.com/forum/membe...4646-68438.jpg
Getting just under 5" of articulation. Tires just clear the fenders with full movement and steering.

Re: MY's Full Custom Build
 

Weight came in at 3088g (6.8 lbs), bare (without the body+accessories) it drops to 2868g (6.3 lbs). The brass portal covers (82g each) and steering knuckles (54g each) account for 436g (0.96 lbs), so could be as low as 5.5 pounds if desired, which I'm happy with. Weight distribution is also right in the ballpark I was shooting for.
http://www.rccrawler.com/forum/membe...4646-68428.jpg
http://www.rccrawler.com/forum/membe...4646-68429.jpg

Hoping to get it out for a real drive this weekend.

Re: MY's Full Custom Build
 

That turned out great man! Good looking rig for sure.


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Re: MY's Full Custom Build
 

Don’t know how I missed all of this!

Great looking interior, can’t even tell the middle was cut out!

Also, I haven’t really been a fan of the JC creep until this. That looks great man! I think that’s perfect for gunmetal, especially with the light grey accent decals.


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Re: MY's Full Custom Build
 

Damn, that is a great looking rig. Well done!

The color scheme you picked for the body is great, I really like how you've detailed it.

Cheers,
Gable