CIM motor issue

[dmellich]

We are using the KOP transmissions w/sprockets and 2 CIM's on each side with treads (belts). We have encountered a situation with the drive system (specifically the motors) that is bugging the heck out of us. When applying "low" current to the motors they produce an annoying "whinning" or "vibrating" noise . It typically lasts less than a second or so and once more current is applied and the robot begins to move (not sure of actuall speed threshhold) the noise stops.

Our thinking is that at the low current the motors are not generating enough torque hence the noise. The problem is we don't have the expertise to determine the actual cause and/or fix.

Any help, insight, or suggestions from you motor "gurus" is much appreciated. Thanks for your time.