Re: Frozen stepper motor shaft

Thanks guys for the feedback... Andy, looks like your suspicion of
corrosion is the culprit. They were stored in their foam containers
and there was no indication of exterior corrosion. I checked the
resistance and it was about 3 Ohms lower than the other motors. I
removed the outer covers (one at a time) and found some mild pitting
from the stator windings on the aluminum covers. There is more
evidence of the corrosion between the stator and the rotor with a
very light rust color on portions of each. The good news... initially
I thought two were frozen... turns out I only have one new paper
weight.

Again Thanks - Mike



--- In CAD_CAM_EDM_DRO@yahoogroups.com, "Andy Wander" <awander@v...>
wrote:

>
> ...I guess if I'm going to be so pedantic I should be

talking "ounce-force", huh............?

>
> I have seen motors that got wet in storage, where water seeped in

along the shaft, and froze things up. (the ones I saw were not
steppers, but you never know, right). The corrosion was not apparent
on casual inspection, as it was pretty much confined to the part of
the shaft INSIDE the bearings.

>
> Andy Wander
> Verrex Corporation
>
> -----Original Message-----
> From: CAD_CAM_EDM_DRO@yahoogroups.com

[mailto:CAD_CAM_EDM_DRO@yahoogroups.com] On Behalf Of Alan Marconett

> Sent: Saturday, January 21, 2006 9:35 PM
> To: CAD_CAM_EDM_DRO@yahoogroups.com
> Subject: Re: [CAD_CAM_EDM_DRO] Frozen stepper motor shaft
>
> Hi Andy,
>
> I agree that it's not oz divided by inches, but it's not oz MINUS

inches either! I'll probably be OK when it comes to the equations.
Each to his/her own! ;>)

>
> The RUST on the shaft/end bells would surely be an indication of a

serious problem! The shafts I've seen on steppers seem to be of a
pretty good steel, I've seldom (if ever?) seen any rust there. Bent
shaft, dented end bells (different name?) as others have mentioned,
would also be serious. But I just took it that they were new/used,
and might actually be OK (hope so!).

>
> Alan KM6VV
> Déjà Vu!
>
>
>
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