Is this normal?

[Pdelcast]

George,

What I see there isn't unusual -- that's only about 1-2mm end play. Some older batches had even more play than that -- because we were allowing the rotor to self-locate during run for best efficiency. As we get our rotor manufacturing (and magnet location consistency) better, we are tightening the end-play up.

As the motor ages, the end-play will increase -- but as long as the end play is the rotor moving between the bearings, no problem. If you start to see the internals of the bearings moving (the race and balls getting worn, or the shields starting to wear and fail) then it is time to replace the bearings.

Patrick