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

--- In CAD_CAM_EDM_DRO@y..., "Les Watts" <leswatts@a...> wrote:
> Hi Dave
>
> I have the 3 volume Bearing manual so let's see here...
>
> Ok I think this is an inch size miniature radial BALL bearing (not
roller).
>
> I don't see the exact part number, but I think it is a
> double shielded unit like NMB DDR1-1438ZZ or NSK R6ZZ.
>
> These units are 7/8" od, 3/8" bore, and 0.2812" (9/32") thick.
>
> A standard electric motor grade ABEC-1 double shielded R6
> is available in MSC for $7 that is this size. ABEC-1 standard grade
> is about $3. The only difference is the electric motor grade has
> a higher polish on the races to run a little quieter. The accuracy
> is the same.
>
> These are normally run with a push fit on the outer race (slight
slip)
> and a press fit on the bore. The outer race is often wave washer
lightly
> preloaded.
>
> Is ther a manufacturer name on the bearing?
> That way I may be able to hunt up the exact number.
> But it sounds like any old ABEC-1 R6 is gonna fit.
>
> Oh...you may want to read up on pressing in bearings...
> you must not apply pressure to the outer race when
> installing them.
>
> 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@j...>
> To: <CAD_CAM_EDM_DRO@y...>
> Sent: Thursday, September 12, 2002 4:47 PM
> Subject: [CAD_CAM_EDM_DRO] Roller Bearings link ? ( was Bad Bearing
( was
> Re: stuck stepper
>
>
> > Hi All,
> >
> > The bearing in the stepper went south.
> >
> > it is an R1-1438HH NMB
> > 3/8 bore, 7/8 OD, 0.3" thick.
> >
> > McMaster has similar bearings but this is
> > slimer than a standard electic motor bearing.
> >
> > I also noticed that the bearing should slip in the housing
> > and is not a press fit. there were a couple pressure washers
> > holding it in place.
> >
> > I guess taking one of these puppies apart is how to learn just
> > what makes them tick.
> >
> > A google search of ball bearings, roller ball bearings, roller
> > bearing, yadda yadda yadda keeps turning up links but none that
offer
> > a selection guide.
> >
> > Anybody have a link to a selection guide ?
> >
> > Dave
> >
> >
> >
> >
> >
> >
> >
> >
> > --- In CAD_CAM_EDM_DRO@y..., "turbulatordude" <davemucha@j...>
wrote:
> > > Hi All,
> > >
> > > Thanks for the insight.
> > >
> > > I decided that since it was stuck that I could not damage it by
> > > opening the case.
> > >
> > >
> > > Got a fresh rag, washed all the metal chips off my hands,
cleanded
> > > the workbench, then swiped a magnet over it just in case.
> > >
> > > I opened the case.
> > >
> > > What I found was that the part of the rotor that I could see
looked
> > > dirty, little like black dust. immeadiatly, I noticed the rear
> > > bearing was loose in the race.
> > >
> > > Inspection showed the bearing had failed, then the rotor had
been
> > > making contact as it was spinning. Wear was evident in both the
> > > rotator and stator.
> > >
> > > I'll get a new bearing to see if it will come back to life, but
not
> > > count on it for any critical applications.
> > >
> > > I am reviewing the idea of using a NEMA23, double/triple stack
> > > instead.
> > >
> > > Thanks again.
> > >
> > > Dave
> > >
> > >
> > >
> > > End of mystery.
> > >
> > >
> > >
> > > --- In CAD_CAM_EDM_DRO@y..., JanRwl@A... wrote:
> > > > In a message dated 9/11/2002 7:43:12 PM Central Standard Time,
> > > > davemucha@j... writes:
> > > >
> > > >
> > > > > There is some slight play with about 15 degess of motion in
one
> > > spot
> > > > > so I assume that it might be physical and not electronical.
> > > >
> > > >
> > > > Yeah, that sounds like a chip of magnetic material "toggling"
in
> > > a "magnet
> > > > tooth slot" in there.
> > > >
> > > >
> > > > [Non-text portions of this message have been removed]
> >
> >
> > Addresses:
> > FAQ: http://www.ktmarketing.com/faq.html
> > FILES: http://groups.yahoo.com/group/CAD_CAM_EDM_DRO/files/
> >
> > OFF Topic POSTS: General Machining
> > If you wish to post on unlimited OT subjects goto:
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reach it if
> you have trouble.
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> >
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as a
> sister site to the CCED group, as many of the same members are
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> >
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