[ARC5] Power up Modulators

[WA5CAB at cs.com]

Dave,

I don't know what Mike may come back with but...  The only reason for buying 
a bearing puller (and the small ones are not high dollar items) would be to 
use to remove an old bearing for disposal and replacement with a new one.  The 
precision ball bearings used in most of our dynamotors are press fits on the 
armature shafts.  They were installed by pressing on the outer end of the inner 
race, which puts no loads on the balls or the outer race.  

But 99% of them install up so closely to the end of the commutator(s) or 
winding core that the only thing you can grab onto in order to remove them is the 
outer race.  When you pull on the outer race in order to remove a properly 
fitted bearing from the armature, you (usually) damage the outer and inner races 
and possibly the balls due to "brinelling".  I.e., you put dents in the races 
and flats on the balls.

So your procedure is or is similar to what I would use unless I had new 
bearings (most of the bearings are still commonly available, BTW).  I'll add the 
comment that some of the bearings are shielded and a smaller percentage may be 
sealed as well.  Given the relatively benign invironments they are going to 
live in, don't hesitate to remove the shields and/or seals if necessary.  And 
don't worry about (or attempt) putting them back on.  Just smear some grease on 
the inside of the disc that usually covers the bearing hole in the bearing and 
brush casting.  That'll seal out dust well enough so long as it isn't being 
driven at high velocity.

In a message dated 11/3/2005 1:24:19 PM Central Standard Time, 
arc5 at ix.netcom.com writes: 
> OK, Mike-  I *know* you're right.  
> I *know* I should buy a bearing puller
> or just take the armatures 
> to a motor shop and let them do it.
> I'm just an old sinner.... ;-).

Robert Downs - Houston
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MVPA 9480
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