RC Oshkosh HEMTT 6×6 Truck
Long time no see! Not Lego this time , but a beast of a truck!
As you may know I’ve not been into Lego as much as I was in the last couple of years. But I have not stopped building! So I decided to keep this website running for you guys that are interested in my work and generally anyone that would like to read 🙂 .
So about the truck. This contraption of wheels, aluminium and electronics is actually way simpler than it looks, although actually building it is a lot more messy than Lego. The truck features:
- 2 Speed RC4WD Gearbox, shifted by a mini Servo
- 6X6 Drive
- Front Leaf spring suspension
- Rear axles on a balance cart suspension
Thanks to the gearbox the truck can run very fast, or very strong, sometimes too strong! (Snapping axle gears had to be reinforced). This set up enables me to to run the truck on various terrains. In addition the rear suspension keep surprising me from day to day. It actually has no springs! It depends fully on the ratio between the positions of the two rear axles. Much like a swing, if one side is up, the other is down. It works flawlessly.
The steering of the front axle is made by an on-axle servo. This servo is mounted on the axle. The benefit of such placement is that no matter at what angle the axle is articulated, the servo will stay on the the same place relatively to to the steering links. That makes the whole steering system very consistent and reliable.
The building process is mainly trial and error. I started with blueprints of the chassis, and came up with the first working prototype. From then on, I continued to make the truck sturdier and the suspensions tougher, arranged the electronics and placed the batteries. The main difference between the prototype and the final model was the motor. I started with a stock 27T (relatively fast) motor, and finished with a new 35T motor. It is much more powerful and suits the truck and gearbox ratios better.
The moment you all been waiting for is finally here, Video!
The first prototype:
You are welcome to check out the following links, they are interesting 🙂
Hope you like it, all questions are welcome in the comments and on the YouTube videos.