Here I will show you from start to finish, how to create a completely one of a kind, remote control rock crawler. These things are pretty fun and can get pretty expensive. Don't pay hundreds of dollars for a tube chassis, build your own!
Step 1: Design
The first thing you need to do is come up with a design. This is what you will use to make the chassis that you will put all of the crawler components on. I would start with something simple, maybe draw it a few times on a piece of paper in class during the school day...
Anyway, you need to draw it out on something sturdy to actual size after you have made a final design decision. I used a piece of wood, cardboard would work. Then you need to decide what your measurements will be. Just saying it right now, simple is safe. I used measurements in increments of 1 half inch. That is to say that I never made a measurement that was not a multiple of 1/2. This helped out a ton when making the frame.