Re: Programming a Crab Drive System
 

Be careful of the ma3's. I prefer the Cherry AN8 sensors with a .5" x .125" magnet. Next year there should be more low cost absolute non contact magnetic sensors on the market.

Re: Programming a Crab Drive System
 

We also very much like the MA3 or MAE3 absolute encoders from US Digital. Other than the fact that the connectors for these are encoders are difficult to connect, they have been wonderful. We used them in 2008 to measure wheel rotation on both our "Speed Racer" lapbot and our hurdling robot. On the "Speed Racer" they ran continuously at high RPMs for the rear wheels, and also at very low RPMs with precision control for the steering feedback and we had no trouble with them at all other than when our abuse of the wiring (without sufficient strain relief) led to a wire coming out of the connector. In 2009, we used the MA3 for precision control of our turret, again with no problems.

We didn't have an MA3 on the robot this year (for the first time in 3 years), but we had great success with the US Digital encoders for our drivetrain transmissions and kicker gearbox.