[ARC5] Bearings for DM-28 dynamotors

[Mike Hanz]

On 11/25/2014 4:30 PM, Clare Owens wrote:
> Now I'll learn how to remove them or rather how hard it is to remove them
> without too much collateral damage :-)  Reading about it is one thing,
> doing it another.  I really do (usually) enjoy trying new things...

The only secret about it is to pull against the back rim of the outer 
bearing race and transfer the reaction to the dynamotor shaft.  Most of 
the -348 dynos I worked on pull off without any problem.  A battery post 
puller should do the job, though you might have to grind the ends a bit 
to get them to grab the back rim of the bearing.  Just don't damage the 
commutator!

I have heard of folks grabbing the outer race with big Vise-Grips held 
semi-vertically in a vise such that the armature is hanging down 
vertical.  If you try this method, have someone hold the armature from 
dropping on the floor when it cones out, and use a 1/4"  brass rod to 
pulse the end of the dynamotor shaft as axially as possible.  Use a 5 
pound hammer...you don't want to pussy foot around the problem.  If it 
doesn't move with a few firm swings, stop...you'll need a different 
solution.

73,
Mike  KC4TOS