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

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@...>
To: <CAD_CAM_EDM_DRO@yahoogroups.com>
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]
>
>
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