Shopsmith Forums

Hello, I recently purchased a used powerpro mark 7. Love it. But there's a bit of bearing knock coming from the headstock on higher speeds. I went through the process of centering the bearings where the two belts connect internal, and while that helped, it seems that it still has a bit of knock. And while I haven't measured it, I would say there is a bit too much runout on the quill ...

Question: Would you all advise new bearings and starting there? Is there a parts diagram I can reference on the powerpro headstock ? I'm pretty handy, I think I could do this myself, but I'm also not opposed to ship the thing back for service if that's the right thing to do. What I think I want to try is replace the bearings in the quill, and perhaps the entire center shaft with both bearings.

Thanks for any pointers!

-Scott

If you remove the quill and run it up to speed do you still have the knock?

BTW, Welcome to the forum.

Have you checked the internal pulleys for loose set screw/off flat center?

Replacing quill bearings is relatively easy it thee are indeed 'handy'.

If by 'center shaft' you mean idler shaft it too is relative easy ...

I would not however replace any bearings until they have been conclusively determined to be the culprit.

May just need to adjust the belts.

Jack

Check for a missing or loose set screw in the hub of the motor pulley. The way the PP system controls speed can loosen set screws. My motor worked loose twice and then I applied blue Loctite to keep it in place.
Bill V

Thanks for the comments guys, I'll check on these ideas and give it a whirl. Good trouble shooting techniques!

-Scott

I vote for the set screw as well. If it is loose, make sure you locktite it or it WILL come lose again. Also make sure you pull the pully up to the snap ring, as that aligns the pully correctly. You will need a 2.5 mm allen wrench.

Finally got to check the set screw. It was nice and tight. the headstock seems to run smooth, but there's a bearing knock coming from somewhere. I have not removed the quill. I assume I have to drill out that metal piece that is preventing me from getting to the hex headed screw that would allow me to remove the quill. Is that what I need to do?

The bearing knock does sound exactly like the one you hear in the installation video. (note mine is a factory Mark 7 headstock not an upgrade)

https://www.youtube.com/watch?v=xCLkH6T1uQE&t=2s

At 1:42:45 he will start to hear a bearing rattle. He then balances the belt tension with the idler shaft. I did this process, and while it did help, it's still too noisy to my liking. This is what leading me to believe it's the idler shaft ...

Thanks for all the help thus far!!!!

-Scott

Should be a putty like substance covering the screw, that can be picked out with a sharp pointed tool. Putty is there to prevent accidental loosening of screw. Be sure to replace it with caulk or similar substance after you replace quill.

Here's an old Sawdust Session that explains removing and replacing quill: http://www.shopsmithacademy.com/SS_Arch ... enance.htm

I guess the power pro had a metal piece there, no putty... I guess I could drill that or idk... Really leaning on ordering an idler shaft with bearings...