1523 used andymark mecanum wheels for the past 4 years and discovered a few differences between them:
6 inch wheels:
- smooth
- break rollers frequently
- easy to replace rollers
- more rollers
8 inch wheels
- less grip
- VERY loud
- easey to replace rollers
- rollers hardly ever break
- vibrate the whole robot
both feature unbreakable hubs
We have experimented with gear ratios, motor choice, and code as well.
2011: CIM drive 12.75:1 gear ratio on 8 inch wheels PID controlled
2012: CIM drive 8.45:1 gear ratio on 8 inch wheels PID controlled
2013: Mini-CIMs 8.45:1 gear ratio on 6 inch wheels PID at first event no PID at second- fifth
2014: Mini-CIMs 5.95:1 gear ratio on 6 inch wheels no PID loops
We are happy with how our 2014 drive is performing although it was probably not a good choice for this years game. All 4 drivetrains have never suffered an on field mechanical failure beyond carpet/ field tape getting caught in the wheels and the occasional roller damage.