Re: [CAD_CAM_EDM_DRO] Roller Bearings link ? ( was Bad Bearing ( was Re: stuck stepper

A bearing seating tool is a good idea. Sometimes you get lucky
and a piece of copper tubing faced off in the lathe is the right size.

As far as ABEC-1 for stepper motors....

I would guess 90% of all stepper, servo, or induction motors
use ABEC-1 tolerance. For your bearing size that means max runout is
typically 0.0004"! About the only reason to use something higher is
if it is in a motorized spindle or something. Also, I have found very
few shops that can properly machine a housing for something
like ABEC-7.

The fact that there is no mention of accuracy in the part number
means it is prob default ABEC-1. In fact I have never seen better than
ABEC-1
in any servo or stepper that was not also a unitized spindle.

Oh one other thing... There has been much mention of partially demagnetizing
steppers by removing the rotors from from the housing. I cannot confirm this
but it might be prudent to keep the rotor in the housing while replacing
bearings.

Les

Leslie Watts
L M Watts Furniture
Tiger, Georgia USA
http://www.alltel.net/~leswatts/wattsfurniturewp.html
engineering page:
http://www.alltel.net/~leswatts/shop.html

----- Original Message -----
From: "turbulatordude" <davemucha@...>
To: <CAD_CAM_EDM_DRO@yahoogroups.com>
Sent: Thursday, September 12, 2002 7:02 PM
Subject: [CAD_CAM_EDM_DRO] Roller Bearings link ? ( was Bad Bearing ( was
Re: stuck stepper


> Hi Les,
>
> I had assumed that there was some higher standard for steppers than a
> plain ABEC-1 electric motor bearing.
>
> The outter race does seem to be a very tight slip fit and the fit on
> the shaft is also a thight slip fit. the shaft out by hand, had to
> persuade the bearing in the housing to come out.
>
> I'll turn a small bearing seating tool for insertion. I do know that
> only the outter race can be used for pressing it into the housing or
> the inner race when pressing on a shaft.
>
> Thanks,
>
> I'll get the bearings with confidence.
> BTY. I assumed that the NMB was the manufacturer.
>
> Dave