Atlas Mill Spindle Pulley Bushing

Rich,

The thread is #8-32. I can't swear that it is original to the machine but the oil plug screw in the 2-step spindle pulley on the MFC parts unit that I have is #8-32 x 1/2 Cup Point Allen Set Screw. It just goes flush. Try that. If it won't go flush, drop back to a 7/16".
 
Here is an update for anyone who is following my adventure.

I received the M1-259 sleeves from Clausing. They are Clausing part number 10-932. They were $6.04 each and shipping to PA was $12.77. The ID of the Clausing part is about 0.002 inch larger than the McMaster part. The Clausing part fits onto the spindle shaft perfectly.

As Robert said, Clausing does not carry the other bearing - the M1-258B- so I had to reduce the length of one of the new M1-259s to .375. My first attempt did not go well. I held it in a 3-jaw chuck and attempted to use a cutoff tool. The part grabbed and crumbled into about 6 pieces. My second attempt was successful.

The mill is now back together. The spindle pulley/gear assembly works nicely. The bearing is smooth and quiet. I ran it for about 60 minutes without load and it is behaving itself just fine.

The ID of the Clausing part seems to be an unusual size that is not off-the-shelf from the usual suppliers of Oilite bushings. I don't know of an alternative to Clausing. I hope that they continue to carry the part. I suppose we could machine the bushing from solid Oilite if we had to, but that would be a chore.

I have found religion with regard to using that little oil hole. I will take the screw out and dribble some 20 weight oil in whenever I use the mill.
 
Thanks for the update. And glad your machine is back in operation.
 
Jon,

I didn't discuss how to part off the M1-259 to make an M1-258B and guess that I should have. You needed to use either a 5C collet (which reallisticly would require that you already had a 1" 5C collet and a collet chuck) or a 7/8" dia. expanding mandrel to hold the M1-259 full circumference on the ID. You could maybe have made the mandrel or there is a cheap Chinese 8-piece set with a 7/8" mandrel that would have worked. I bought a couple of the sets years ago and have used them three or four times. I have also from time to time seen the same mandrels available individually.
 
Thanks Robert. I was able to cut the bushing on the second attempt. I used the least pressure in the 3-jaw that I could without slipping and a sharp cutoff blade. That worked with the McMaster part too. But a mandrel to fit the ID would have been the right way. A machinist where I work told me that he sometimes cut bushings from the ID using a boring bar set up as a cutoff tool. I don't know why that would be better than cutting the OD but he said it worked better sometimes.
 
Oilite is relatively soft. It's possible that parting off from the OD might leave a slight ridge on the ID, whereas parting from the inside wouldn't
 
You must log in or register to reply here.
Back
Top