Victors not synchronized - dual motor train

[Rickertsen2]

Somwhere i read a claim that the speed controllers are perfectly calibrated to work with ifi controllers and that the calibration is only for using victors with rc systems that lack trim. I don't remember where i heard this, but it is very wrong. On one of our 4 motor drive prototypes, the speed controllers were soo off that it was impossible to trim the joystick such that at least one motor was not trying to move at all times. The problem was easily fixed by calibrating the speed controllers.