Sumo wheels are important for a high-performance sumo robot. Here I explain what I learned after two years in the Spanish National Liga (LNRC).
The goal of create your own wheels is to obtain the maximum friction, therefore more traction. In a sumo battle all the robots have the same weight, in this case 3 kg. In case of two robots are faced, he robot which have more friction win. Friction is proportional to the friction coefficient and the force to the ground. As all the robots should weight the same, we suppose that the force is also equal. Having a higher friction coefficient could in some case determine the winner.
I have realised a wood prototype of the wheels because the manufactured wheels took longer than expected. The final wheels works nice to test some basic functionality of the robot like try the motors, chassis dimensions and general mobility. Here leave some photos of them:
The tires have to been specially manufactured with specific given dimensions to maximise the contact area with the floor. Therefore for design, the front motors have an encoder built, therefore they are bigger and the tires are narrower than the rear one.
The specifications of the tires can be seen in the following pictures:
The results are a high-quality robot wheel with a lot of friction with the ground. The wheels adhere to the ground surface properly without being sticky.