Re: Replacing bearings in stepper motor

Thanks Jan for your very valuable info.
I was inclined to put new bearings in all of my steppers just to ensure maximum working life.

Its a lot harder here in Australia digging up larger steppers. Postage and packing costs from the US can be higher than the purchase cost of a secondhand larger motor through Ebay. So looking after what you can get is very important.

After reading your advice about claggy bearings I will certainly replace them all just in case some of them are very near the end of their working life.

Regards
Bob Thomas

>
> > Are there any hazards replacing bearing in a stepper motor?
> >
> >
>
> Bob: Yes. I have DONE this, and it takes AT LEAST "care".
>
> First, the rotor is a multi-poled magnet, and looks like two or four "thick
> pinion gears". It is alnico, and very brittle, so if those "gear teeth" rub
> on the like-teeth of the stator (which has the windings), it will "chip off"
> small particles that will JAMB the thing, when you re-assemble it! So, this
> is why they will NOT warrant a stepper that has been dissassembled "outside
> the factory" (they have jigs to hold all the parts concentric for assy.).
>
> The bearings I had in the one I had to re-do were NOT sealed nor
> "life-lubricated"! They were "shielded, only", and got FULL of dust, so
> "froze up". Use DOUBLE-SEALED, Lubricated for life type bearings! Be VERY
> careful when you pull 'em off the shaft, and be SURE you push ONLY on the
> inner-race to install the new ones (i.e., don't transmit the "pushing force"
> through the balls!)
>
> Check the solder-connections to the lead-wires "while you're in there", as
> the ones on my NICE, new S.E. motor looked as if they had been done by
> dexterity-challenged children!
>
> Lotsa luck! Jan Rowland
>
>
> [Non-text portions of this message have been removed]