- Joined
- Jan 11, 2013
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The final post of the ridiculous drill press belt change ...
I used the drilling and tapping method, screwing/drawing it up from above with the apparatus here:
I found a piece of round, I it sat on top, around the bearing retainer. Then a bar with holes, bolt went through that, into tapped holes in bearing retainer, and drew it up. It was so snug and stiff, I needed to use a huge channel locks to turn the bearing retainer back and forth from inside the belt housing while cranking drawing it up with those bolts (as you can see above).
I did not have any visible rust or gunk in there, and this one was NoT a slip fit as was supposed to be the case
... But I put the bearing retainer on the lathe and filed the outer surface down a thou or two. I then used one of the rough gray scotch-brite pads to smooth the filed surface more. I thought I would take it down even more, but I put it back as a pretty close slip fit as you mentioned (and glad I did - more below).
I then used the scotch brite as much as I could to open up the actual bearing retainer recess for a close slip fit there too.
Here is a shot of the top, third, bearing in place, with the retainer drawn up out of the way:
As it turns out, on top of the spindle pulley is a THIRD bearing. It is a pretty standard, open, caged motor bearing. It must be there to relieve the belt stress away from the top spindle bearing, and share the side load. So this makes sense of this whole bearing retainer mess. I think in later models they made this more easily maintainable, but a nice feature, obviously meant for long time reliability and accuracy.
It was good to clean up in there anyway. I know it wouldn't have been much to finish taking the spindle apart, but I decided to leave that for another project after I get it running. It was very clean, and feels smooth. the top spindle bearing inside felt nice. Now that I worked the top end over, future access for work will be a piece of cake.
Now to wire up the motor and get it spinning!!
Bernie
I used the drilling and tapping method, screwing/drawing it up from above with the apparatus here:
I found a piece of round, I it sat on top, around the bearing retainer. Then a bar with holes, bolt went through that, into tapped holes in bearing retainer, and drew it up. It was so snug and stiff, I needed to use a huge channel locks to turn the bearing retainer back and forth from inside the belt housing while cranking drawing it up with those bolts (as you can see above).
I did not have any visible rust or gunk in there, and this one was NoT a slip fit as was supposed to be the case
... But I put the bearing retainer on the lathe and filed the outer surface down a thou or two. I then used one of the rough gray scotch-brite pads to smooth the filed surface more. I thought I would take it down even more, but I put it back as a pretty close slip fit as you mentioned (and glad I did - more below).
I then used the scotch brite as much as I could to open up the actual bearing retainer recess for a close slip fit there too.
Here is a shot of the top, third, bearing in place, with the retainer drawn up out of the way:
As it turns out, on top of the spindle pulley is a THIRD bearing. It is a pretty standard, open, caged motor bearing. It must be there to relieve the belt stress away from the top spindle bearing, and share the side load. So this makes sense of this whole bearing retainer mess. I think in later models they made this more easily maintainable, but a nice feature, obviously meant for long time reliability and accuracy.
It was good to clean up in there anyway. I know it wouldn't have been much to finish taking the spindle apart, but I decided to leave that for another project after I get it running. It was very clean, and feels smooth. the top spindle bearing inside felt nice. Now that I worked the top end over, future access for work will be a piece of cake.
Now to wire up the motor and get it spinning!!
Bernie