Here's several parts to enable you to fit a (in my case heavily dremeled) Tamiya Sand Scorcher body onto your HG P402 chassis. It was a big challenge for me to make everything fit neatly and make the steering and suspension function properly, but it looks very promising! Still a work in progress, so I can't wait to drive it properly!
If you use all the files here, you can convert your stock HG P402 chassis into a shorter, studier chassis, featuring a rear 4-link rear, 3-link + panhard front suspension and a larger steering angle!
Note that I moved all 4 shock hoops inwards. Mount the front end of the shock hoop into the rear hole (if that makes sense). Slightly bend the hoop down and drill a new hole in your chassis beam to mount the other end. I also cut off the front of the chassis beams where the servo mount ends. I will probably also cut up the rear end of the chassis beams, but more on that later..
The parts to print:
- Servo Mount
- C-hubs with 8 degrees of caster and a panhard mount. Mirror 1 of these accordingly.
- Upper link mounts - let's get rid of those nasty Y-spaghettis
- Battery mount
- Body mounts
Everything bolts up with M3 (mostly M3x14) hardware I also used M3x8 (to connect the c-hubs to the axles, M3x16, M3x20. Because of my earlier experiences with PLA, i decided to design the holes to be very easily driled out to 2.5/2.6mm. You can then either tap a thread or just "force" your bolt in there (use quality hardware if you decide to do this).
I made all the suspension linkage of M4 threaded rod and Traxxas 5347 rod connectors. Adjuist the length to the tire size and body you're using. I finished the lower links and steering links off with some 4x6mm aluminium pipe. For the upper links and panhard link i cut up some 4mm shrink tube (no shrinking required) and forced it around the threads.
I had to use a 1.25" or 32mm servo horn to get the right linkage angle and steering throw.
To make the panhard bar fit, you'll have to bend and twist the link or it will either hit the axle or your chassis beam/servo mount. It takes a bit of fiddling, but it'll work in the end!
For this build I managed to get my hands on some Axial Icon 90mm oil shocks and fitted some softer lower springs i had randomly laying around.
This build took me a lot of figuring out and I may not have covered everything, so feel free to ask any questions!
Front body mount is made to fit into the shock hoops instead of your body posts. The rear body mount fits on top of your body posts. I used velcro to mount the body to them. Print the rear mount with the tallest side facing down. You may need to use a 2-3mm brim for this part.
I printed this "nose-down" with supports. Not sure if this is ideal, so do it differently as you please. It screws to the chassis using M3x14 bolts. Note that there is no mounting hole on the front left, to make room for the bolt that holds the panhard bar. Room for improvement here! I just drilled an extra 2.5mm hole through the chassis, into the part and jammed an m3x10 nut in. Not the most elegant way to do it, but it sits just fine.
To make the battery fit between the body, it had to sit as close to the transmission as possible. I use a 2S 5800mAh hardcase lipo which leaves just a small gap between the spur and shifting linkage. I used velcro straps to clamp the battery tight on there (there is no other sideways fixation due to the narrow fit between the body). Make sure that your battery is centered! (or use a shorty lipo).
You will need to mirror one of these or your caster will be going the wrong way! I used supports inside the hubs which can be somewhat of a struggle to remove (don't make them too strong). I used M3x8mm bolts on the front and M3x14 bolts for the rear side/shock.
Upper link mounts
Print these flat-side down using a tiny support for the axle mount. Take your axle apart, take out he ball joint and screw them together. Make your printed mount fit into the newly enlarged hole. From the other side, thread in an M3x14 or M3x16 bolt. Make sure you use a 3mm flat washer behind the head or the bolt won't fixyour part properly onto the axle! Use M3x14 bolts to mount your upper links. On the chassis side of your link, use spacers (3mm washers, 2pcs each) between the pivot ball and the chassis beam.