Motor drive shaft/bearing fit question
 

I have 3 brushless 1/8 motors by different mfgs. All the motor shafts have a pretty tight fit (when new) with the bearings, you cannot feel play in them and they don't really move if you try to push the shaft into the can.

I just got my first 1/10 size motor and it is quite easy to move the drive shaft/rotor assembly in the bearings. I removed the back cover and you can see the shaft sliding freely in the ID of bearing. It is brand new.

Is this OK or normal? Seems like something spinning that fast should have a tighter fit w/ the bearings.

Hi Precision1,

As you can see with this pitcure :

http://sylveris.free.fr/Bearing rules.jpg

The motor case is the drawing at the right down of the picture.
So the axle needs to be "free" into the inner ring.
But you can't compare the tolerances then the radial play between the axle and the bearing, and the axial movement, these are 2 different things !
Bye !