Two robots face off and try to throw each other off of a table! It'll make more sense after you watch the video...
More footage from actual student-built JudoBots:
Updated version from my book Rubber Band Engineer
I call them JudoBots because of the way they seem to throw and grapple with each other during combat.
Although designed for children in grades 4-6, I think just about anyone can have fun with this. Even parents can't resist trying it out!
The bots are assembled from four components built separate from one another: the base, the stand, the arm, and the hydraulic system. The hydraulic system uses plastic syringes as pistons and water as the hydraulic fluid.