Off Road, 4wd (or 6wd) RC Car by davidbec08

Last crawled date: 3 years ago

This is a strong (high load carrying) off road RC chassis. It is designed to crawl around carrying things and to climb very steep inclines. It has fully independent suspension and 1 motor at each wheel.
You can see the 4wd version here:
https://youtu.be/a39qIS8JGv4
and a little more of its rock crawling abilities here:
https://youtu.be/-LaEoF4j1Rk
and with the FPV Camera from the Tank upgrade:
https://youtu.be/4jV0W-KFchE
I have also included plans and mounts for a 6wd version. (If you build this one, the axles need to be closer together as it is skid steer. Squarish vehicles work better). It makes use of a different mount for the electronics (transversely instead of longitudinally mounted).
It is skid steer, and makes use of an Aluminium tube for the chassis rail. This keeps weight down.
I've included the Rhino files so you can modify it more easily to your application.
INSTRUCTIONS:
CONTROL ARMS/WISHBONES: You'll need some 5-6.5mm aluminium rods (drill the holes out to suit what you have). Smaller is better.
RC: I used the cheapest of everything I could find, and went with 2x motor speed controllers, 1 for each side i.e. the left side motors are connected in parallel to one, the right side motors to the other. I use one stick of the RC controller to control the vehicle in an odd way: top left = fwd, bottom right = back, left bottom = spin left, right bottom = spin right and everything in between is turning left or right while going fwd or back. It doesn't take any getting used to.
You could use an Arduino or similar of course, like I did for our off road SLAM robot. This chassis actually has some advantages over that one, but you'd need to modify the various carriers for the LIDAR.
MOTORS: I used Dagu Wild Thumper motors (6V) and wheels and mounts. There are 34:1 Metal Gearmotor 25Dx52L mm (High Power) Code: MEC-30089. 4.3 kg-cm and 5.5 A stall.
Make sure you tighten the screws attaching the gearbox to the motor (I use loctite to make sure they don't work loose. They come from loose from the factory).
MOUNTS FOR MOTORS: Pololu 25D mm Metal Gearmotor Bracket (comes in pairs). The holes in the motor carrier (printed) align with these mounts
BATTERY: I used a 3300 mAh NiMH 7.2V battery. If you go 6wd you might try a higher capacity LiPo, though you'll get a lot of the NiMH for the 4wd.
SPRINGS: #157000003/22497 1/10 Model Car 85mm Adjustable Aluminum Shock absorber (2pc Blue)
SPEED CONTROLLER: 2x #9261000018/32025 HobbyKing X-Car 45A Brushed Car ESC chosen for the rating (45A) and price. any brand with similar specs would do. Remember it is skid steer so you'll be loading the motors quite frequently