Shopsmith Forums

I cleaned my speed changer, which I've done often. When I ran the speed up to check it, the speed control retaining clip came off. This is the wire loop (3/4" x 7/8") that goes over the leaf spring on the quadrant assembly and clips into the shaft in the center of the control sheave assembly. The two ends of the clip go into a hole in the shaft. One of the ends came out. I eventually got it back in place and tried again, with the same result. I tried bending the two ends of the clip together so they would fit more tightly into the shaft, but that didn't work. I guess I can try bending it farther, but I'm concerned because I don't know what caused this. This is a Mark V dating from sometime in the 90s. Any thoughts or ideas? Thanks.

sp99keeler64 wrote:I cleaned my speed changer, which I've done often. When I ran the speed up to check it, the speed control retaining clip came off. This is the wire loop (3/4" x 7/8") that goes over the leaf spring on the quadrant assembly and clips into the shaft in the center of the control sheave assembly. The two ends of the clip go into a hole in the shaft. One of the ends came out. I eventually got it back in place and tried again, with the same result. I tried bending the two ends of the clip together so they would fit more tightly into the shaft, but that didn't work. I guess I can try bending it farther, but I'm concerned because I don't know what caused this. This is a Mark V dating from sometime in the 90s. Any thoughts or ideas? Thanks.

It sounds like the button bearing is failing, seizing up. If the control sheave isn't damaged, it is possible to replace just the bearing. if not you will need a new control sheave.

Jacob Anderson sells the bearing, Shopsmith only sells the sheave/bearing assembly.

[youtube]https://www.youtube.com/watch?v=2hJWnRqgq1Q[/youtube]

Thanks, Ron. The button seems to turn smoothly but who knows what happens at higher speed. I need to get the Shopsmith working again, so I plan to buy the control sheave assembly from Shopsmith. It appears to include the retaining clip. I hope to get expedited delivery by calling them tomorrow (Monday). Of course this happened while I'm working to a deadline, so thanks again for your quick response.

Since it's spinning freely I would also make sure that the Control Sheave is sliding freely on the idler shaft. You could also take the motor belt off and just run the control over it's range to see if you feel anything, especially at the speed you are having trouble. We are presuming that you are not hearing anything abnormal.

- David

The only purpose of that clip is to prevent the button from rotating with the sheave. It is not there to 'pull' the control sheave. Preventing that pulling is the reason adequate lubrication of both movable sheaves is necessary.

Thanks to Ron Dyck I got my machine running again after the control sheave bearing seized. It's back together, with a brand new speed control assembly as well as the new control sheave assembly.

It works okay except that the speed control is very stiff. I put a little grease on the quadrant and worm gear and oiled everything I could think of, including the worm gear shaft and control sheave idler shaft.

Any advice or suggestions?

Thanks.

Check that the moving sheave on the motor is sliding freely over the full range of motion.

Is it 'stiff' going both up and down?

And how rapidly are you attempting to turn the knob?

Ron, after I replaced the control sheave assembly (and speed changer), the action was still pretty stiff. As you suggested, I checked the drive pulley shaft and oiled it (again). That seemed to help but the speed control is still pretty stiff.

I'm wondering if the V-belt could be part of the problem. My Mark V dates from 1998 and I assume it's the original belt. Any thoughts?

Thanks.

sp99keeler64 wrote:Ron, after I replaced the control sheave assembly (and speed changer), the action was still pretty stiff. As you suggested, I checked the drive pulley shaft and oiled it (again). That seemed to help but the speed control is still pretty stiff.

I'm wondering if the V-belt could be part of the problem. My Mark V dates from 1998 and I assume it's the original belt. Any thoughts?

Thanks.

My knowledge here is mostly theoretical, as my Mark 5 got stuck in rebuild limbo, and my actual experience is primarily with my 10ER's.
Other members like jpg have decades of experience and will be better guides.
I do know my quadrant turned easier after I did Bill Mayo's mod. https://www.shopsmith.com/ss_forum/down ... p?id=34357

Also, it will turn easier fast to slow, going the other way the belt has to push the motor sheaves apart against the pressure of the spring.