Shaft specs for CIM motors

[philso]

Did you install a shooter wheel directly on the motor shaft? Did you happen to have some of these motors fail?

We don't have manufacturer's specifications but a teardown of a failed motor (mini-CIM) showed that there was a ball bearing at the output shaft end and a sleeve bearing at the other end. The sleeve bearing was severely worn after about 20-30 shots through our shooter. This lead to the rotor dragging on the stator magnets.

I asked one of the engineers in our Motor Design group about the failure we experienced the other day. He said that motors experiencing side loads above what a belt or a chain would apply must use ball or roller bearings at both ends of the shaft and that sleeve bearings are inadequate for such applications.