Re: (ET) How do I change motor bearings?

["Steven Naugler" <snaugler earthlink net>]

Sorry folks....  The bolt to cut off should be a 1/4-28 fine thread by 1.5
to2 inches long, not a 1/4-20.  Sorry for the typo.

Steve Naugler

> -----Original Message-----
> From: Steven Naugler <snaugler earthlink net>
> To: David Roden (Akron, Ohio) <roden ald net>;
> elec-trak cosmos5 phy tufts edu <elec-trak cosmos5 phy tufts edu>
> Date: Monday, June 07, 1999 1:24 AM
> Subject: Re: (ET) How do I change motor bearings?
>
>
> >Dave, I've done this to 6 motors, so hopefully I can give some pointers.
> >
> >1.  The job is much easier with a split bearing puller and either a 
> >small
> >hydraulic press or an arbor press.
> >2.  You'll also need a 1-1/2 to 2 inch long 1/4-20 bolt with the head
> >curtoff.
> >3.  You must remove the blade holder first.  If the blade holder doesn't
> >pull off easily, screw the cut off bolt into the blade end of the motor
> >shaft.  Use a split bearing puller to support the motor by the blade
holder
> >so that you can push the cut off 1/4-20 screw with the press.  When the
> >blade holder comes loose, the motor will drop, so hold on to it as you
> press
> >off the blade holder.
> >4.  With the blade holder off you can take the motor apart.  The 
> >bearings
> >should stay on the armature.
> >5.  Using the split bearing pullers and a press you can remove the
> bearings.
> >Keep track of any washers or spacers and note carefully their positions.
> >They must go back in the original positions.
> >6.  When you press new bearings on, only press on the inner races.  I
> >recommend replacing the original shielded bearings with sealed bearings.
> >7.  When you reassemble the motors, you must restrain the brushes.  
> >There
> >are holes in the brush end of the motor that paper clips or toothpicks
can
> >be inserted to keep the brushes out far enough to clear the bearing
during
> >motor reassembly.
> >8.  If you have old motors where the blades don't have fiber clutch
washers
> >but are pinned to the blade holders, you should purchase the new style
> blade
> >holder with fiber clutches.
> >    That was a very abbreviated set of rebuild instructions that only
> >touched on bearing replacement.  If you have other questions, just e 
> >mail
> >away.
> >
> >Steve Naugler
> >
> >----- Original Message -----
> >From: David Roden (Akron, Ohio) <roden ald net>
> >To: <elec-trak cosmos5 phy tufts edu>
> >Sent: Sunday, June 06, 1999 11:00 PM
> >Subject: (ET) How do I change motor bearings?
> >
> >
> >> Stupid question ... no, make that ~ignorant~ question (as the song
says,
> >> ignorance can be cured, but stupidity is forever).
> >>
> >> My mower motor bearings are ~rough~.  After Matthew Magda's sad post
> >> about his broken motor magnet, I decided not to tempt fate any longer.
> >>
> >> Hmm, how do I change the bearings in my mower motors?  Getting to the
> >> rear (top) bearing seems easy -- take off the end cap, remove the nuts
> >> and brush carrier, and there it is.  (Does it just lift out?  I 
> >> haven't
> >> tried yet.)
> >>
> >> But the front (bottom) bearing is not so obvious.  Do I have to pull
the
> >> blade mount off the shaft?   What kind of puller do I need?  How do I
> >> replace the blade mount when I'm finished?  Once the blade mount is
> >> pulled, does the armature just pull out of the housing?
> >>
> >> I want to do this right, and not destroy an expensive motor in the
> >> process.  Please help, and thanks for the coaching!
> >>
> >>
> >
>
>