We recently got some Toughbox Nanos from AndyMark and noticed that after we switched the output shafts that
some of them could no longer be turned by hand when a CIM was installed. I tweaked the tightness of some of the CIM mounting screws and occasionally saw this problem disappear. On one I loosened the center bearing retainer screws (seen below) so that they no longer contacted the bearing, and I was able to spin the shaft by hand again.
It is a weird intermittent problem, but the difference in gearbox operation has me worried about how consistent our drivetrain will be. Intermittent problems like this have cause huge headaches for us in the past and we would love to find a reliable way to fix this. I'm hoping that this is a type of problem that experienced teams know how to work around, or know the cause of.
Can anyone offer ideas, suggestions, or even guesses as to what we can try to fix this? Thanks in advance.