Old, staying for reference [Lego Rock Crawler (With Instructions)]
A rock crawling remote controlled vehicle. No obstacle too tough for it!
For a long time a saw other people build or drive rock crawlers, and their abilities amazed me. I never thought XL motors could give so much torque for a vehicle to give it a chance in going over the obstacles it clears. So I thought why not give it a try and see how good can I get?
The outcome is much much better than I expected, it can literally go over everything (well not everything, but lots of stuff :)). The first thing I started with was the suspension. Which is the four link suspension of course. From my prior experience I thought the links in this kind of suspension must all originate and end in the same line. But after a little research I figured out they don’t have to, a thing that really helped. The next thing I paid attention to was the chassis and the axles, lets start with the chassis. Chassis for a rock crawler must be dead simple and lightweight. So what I did was to build 2 flat (2D) sides of the chassis and connect them with horizontal liftarms. The chassis consist a battery box mounting place, a receiver and 4 ball joints to mount the shock absorbers on. And now for the axles, a rock crawler needs 2 strong solid axles. The rear axel was just a solid one. But the front one had to be steered, in order to get rid of ant U-joint problems I mounted the steering M motor to the axel itself.
That’s it for the design. Lets move on to its performance. In my opinion it has optimal speed. It isn’t too slow and boring and not too fast-it doesn’t slip off obstacles because of its speed. If we talk about slipping, I must say that that the Lego tires impressed me. I never thought they will be so good! And the suspension works great as well. It has about 45 degrees of travel on each side, and as I know- thats good 😉
As I always write, a conclusion. So what are we left after all this rubbish?
- A cool rock crawler with a VW Beetle body
- 4 link suspension
- 2 XL’s for drive + M for steering