[RRLedford]

We are doing a Mechanum drive for Block Party this year, using the very affordable VEX mechanum plastic hub wheels. We need the encoders to allow the mechanum drive controling S/W to function properly. BTW, for their price, these wheels work very well, if you can come up with a hub scheme for them that eliminates the tiny square shaft in favor of a sturdier one.

I agree that the Tetrix scheme for externally adding encoders is horrible, and exposes them to far too much stress and damage, usually in a very short amount of time. It forces gears & sprockets to be mounted further away from the motor gearbox, where they will tend to more easily & quickly damage it, or where they will cause the motor to shift position in the not-so-solid of a design TETRIX motor mount clamp.

Even when the encoders themselves are not internally damaged, the lack of a strain relief at the point where their wire assembly enters their micro-connector causes early failures of the wiring assembly there too.

When you combine the other TETRIX scheme for a motor with an eccentric output shaft as a way for adjusting gear & sprocket spacing, this adds even more problems for preventing the encoder wires from breaking at the connector, as the moter gets twisted in the mount clamp.

We have used urethane and silicone glue to make strain reliefs and to glue wires to side of motor case. we also use lots of ties to keep encoder wires out of harms way as much as possible.

The VEX motors with internal encoders are so much more appealing, but just too weak for most of our needs.

-Dick Ledford