Shopsmith Forums

with the back cover off...I can see small sparks where the shaft meets the speed controller. Is this normal? Also my speed controller won't go any lower than Dado even though I have lubricated according to videos.

rmoore wrote: ↑Wed Jul 28, 2021 11:15 am with the back cover off...I can see small sparks where the shaft meets the speed controller. Is this normal? Also my speed controller won't go any lower than Dado even though I have lubricated according to videos.

There is a small bearing, known as the button bearing, on the control sheave. My first thought is that yours is seized, causing the button to rotate in relation to the speed control and giving a grinder-like result. That's the first thing I would look at. Then you'd need to look at what else might be damaged to decide how to proceed. I think Shopsmith only sells the Control Sheave and Button Bearing as as assembly. There are aftermarket sources for the bearing IF your control sheave is undamaged.

If I'm right above, then the speed control indication/limitation is likely a separate problem. Most likely one of the moving sheaves is not sliding freely on its shaft or there is something limiting its travel. This is most common with the floating sheave on the motor shaft. In any case, non-electrical sparks probably mean small metal bits in the headstock, so a thorough disassembly, cleaning, and lubrication would be a good idea. Also the wire hoop from the button is probably somewhere in the bottom of your headstock.

- David

" Also the wire hoop from the button is probably somewhere in the bottom of your headstock."

It also is now likely a different shape.

I think you are gonna want a new porkchop.

rmoore,

This is a case where pictures will help in figuring out the problem(s). David and JPG have given you some things to check and I agree based on the description of the problem. It may be a good time to do some removal of parts to check their condition and function. One being the Speed Control Assembly. Doing that will give you better access to the Idler Sheave to check that it moves freely on the shaft. Check the button bearing on the end of it to see if it turns freely and has the wire loop. With the Belt Cover off you can check by hand the motor sheave to see that it is not sticking at any point between open and closed. With the Speed Control Assembly out you can check for excessive wear on the teeth of the Quadrant Assembly aka "pork chop" and worm gear seeing that it turns smoothly.

David, Russ and JPG....I am so thankful for your help. While I have some mechanical aptitude this is still a bit challenging. I have attached three photos which may be of benefit if I have in deed attached them properly.

As the piece holding the button bearing in the control sheave seems to be broken I assume that I need to buy a new control sheave assembly. Would you concur? The sheave does seem to slide freely but not sure how difficult it is to replace the button bearing?

Also, I am thinking that I need to buy a new speed control assembly since mine is worn?

The third picture is part of a broken spring. I am going to have to investigate where it came from. It was in the bottom of the pan when I opened it. I think the other spring attaches to the front of the dial indicator. There is also what appears to be part of a bearing that was in the pan. Not sure where if came from.

Any additional thoughts are quite appreciated. Let me know if the photos do not show up or are unclear and I can try again.

Richard

No pix!

could someone please give me some guidance on attaching a jpeg file?
Thanks

Your picture came through fine this time. The link below may help in understanding how to post pictures.

viewtopic.php?f=7&t=19246

The sheave needs the the button bearing with the wire loop replaced. That's the broken piece from picture 6 at the bottom. You can try either getting the button bearing with the wire loop (non-OEM) or replace the Sheave assembly. My other concern there is how much has the end where the button bearing goes been worn down rubbing directly on the damaged area of the Quadrant Assembly. In that same picture the other wire spring part goes behind the Speed Control Dial and still looks okay. The Quadrant Assembly aka "pork chop" has a lot of wear from the sheave rubbing directly against it. I agree it should be replaced. If the rest of the Speed Control Assembly is in good shape you can replace just the pork chop. The pork chop is held in place by a roll pin but when reassembled others have used a machine screw and lock nut instead.

Thanks so much for your help Russ.
Richard Moore