pic: holonomic vex robot

[cire]

I dont think its the motors being biased, its probably differences in friction from the motor to the wheels, every robot in vex seems to have the problem, even FIRST robots with 2WD and castors have this problem without any correction.

[TheOtherGuy]

I didn't have any wheels on the motor. The shaft went straight into the encoder and nothing else. And you do have to remember that they are vex motors, which, I'm sorry to say, aren't the hightest quality motors out there in the market.

EDIT:
I tested 4 more motors using the same program. The motors were consistantly about 3% faster going backwards than forwards.

Motor 1
Forward: 10339
Backward: 10780

Motor 2
Forward: 10136
Backward: 10409

Motor 3
Forward: 9976
Backward: 10269

Motor 4
Forward: 10215
Backward: 10711

Motor 5
Forward: 10070
Backward: 10280

[Matt H.]

Thanks Kevin,
I hope this settles the question of motor biasing. Also any distances counted without wheels will only be increased by added stress on the motor.

[EHaskins]

I was a FLL programmer for three years, and when using lego motors every motor ran at a different speed. I don't think this is something that can be overcome when using DC motors.

I would like to see the code to make that move.