"Dr. Doctor" wrote:

you need to get a hold of the armature in a way that wont damage it so you
can unthread the impeller. some units have a slot at the top end of the
armature for a screwdriver or the top end of the armature will stick out
enough that you can use a soft jaw vise to hold it while you turn the
impeller off.




When something is screwed onto a motor shaft, it should have some
nondestructive way to keep the motor from turning while the item is
unscrewed (assuming that the system is well designed). Look for a hole
somewhere into which you can insert a pin (allen wrench or something
like that) to lock the rotor. If you can see a fan in the motor, you
might be able to place a screwdriver blade between the fan blades to
hold it, but only if the fan blades are substantial, and not thin sheet
metal. You don't want to bend them or you could be looking at a motor
rebuild job.