I expected that the robots would push each other most of the time during the sumo matches. So I put emphasis on the push power. I also expected that the robot can use 2 or 3 motors at most because of the source power limit. 2.00 MB Spider has four legs. There are two legs on each side.
Spider has two motors for driving the legs.
The leg mechanism uses link chains. This mechanism transforms rotational motion into oscillatory motion. The oscillatory motion produces thrust of the robot.