During the past two weeks, 3 teams have contacted us regarding some durability problems with these wheels. I have recently talked to one team today who had broken wheels at SVR. This is the same wheel that was used in 2012, with the same HiGrip tread. The only difference is that the tread is colored white this year. In 2012, we did not receive complaints regarding the durability of these wheels.
From my experience at regionals this year, there is much higher speed being reached by the robots in this open playing field. Robots are hitting each other at high speed within the field, and there are not field barriers (steps, etc.) present to slow them down. During these collisions, the wheel is getting a high side load. Combine this side load with a high tractive force of the wheel, and we have high stress on the wheel bore, spokes, and rim.
We have a short term and a long term plan to fix this wheel.
- Short term: We suggest putting some 2-part epoxy in the area immediately outside of the bearing bore rim, in the pockets next to the screw holes. Putting a filler material in this area will help decrease the chance that the bore will break down.
- Long term: We will improve the mold this summer for this wheel, beefing up the bore area, the rim, and the spokes. We may even try some other plastic co-polymers to see what has higher strength and higher impact resistance. Our current material is polycarbonate.
Sincerely,
Andy Baker
President
AndyMark, Inc.