Shopsmith Forums

We have a Mark V from 1979 and have replaced a lot of parts. We still can not make it slow down past H on the speed dial. The things we have done; replaced almost all bearings, replaced both belts(both are OME), replaced the speed control assembly.

After the bearing change and cleaning up with lubrication it ran great for no more the 8hrs of use. Then it stopped slowing down past the H on speed dial. We oiled everything again and have been messing with it non stop but can not find a problem that we can see. Can anyone asset on this?

Hope to hear from you all soon!
CW

Did you clean and polish the motor shaft and the control sheave shaft ? If there is dirt or other debris on those shafts then the speed control will probably hang up and bind. I polish the motor shaft using crocus cloth and bring it to a bright finish and the same for the control sheave shaft. When reassembling use plenty of oil. Make sure that the speed control quadrant is not damaged and also that it mounted correctly. After reassembling you will have to perform a high speed adjustment to get the indicator dial properly indexed. All of the instructions are in the manuals or on the Shopsmith website and this website if you do a search for the info.
Let us know if you have any other problems.
Bill V

"Then it stopped slowing down past the H on speed dial."

What does that mean? Adjusting the speed control below H produces no speed change even though the indicator dial goes all the way to slow?

Or does it mean you cannot make the speed control move below "H"?

If the former, the floating sheave on the motor shaft is likely failing to open the motor pulley. That will likely result in something similar to the second. So is it both?

I think you need to verify easy movement of the movable sheaves manually.

JPG,
Sorry about the confusion on this and what is happening is the speed control is not wanting to move past "H". Do not want to force it in which we may cause more damage and have already put so much work into it.
On the note of the sheaves moving freely/manually when we had it pulled apart replacing the bearings we cleaned and made sure everything was moving appropriately before reassembling.

CW

JPG wrote: Sat Jun 26, 2021 10:19 pm "Then it stopped slowing down past the H on speed dial."

What does that mean? Adjusting the speed control below H produces no speed change even though the indicator dial goes all the way to slow?

Or does it mean you cannot make the speed control move below "H"?

If the former, the floating sheave on the motor shaft is likely failing to open the motor pulley. That will likely result in something similar to the second. So is it both?

I think you need to verify easy movement of the movable sheaves manually.

Here is a video that Jacob Anderson made showing how he sets the speed. Not sure if that is helpful.
https://www.youtube.com/watch?v=GWVxeTqUgT8

Here is the method for performing a high speed adjustment with photos and a write up done by Dan at songofthegreatlakes.com
http://www.songofthegreatlakes.com/sshighspeed.htm

Pictures might help. Especially of the speed control shot through the access hole in the back of the headstock and of the belts and sheaves taken with the belt cover removed. I would take the pics at speed "H."

Please confirm: Did you replace the entire speed control assembly as opposed to the quadrant assembly? (G Vs. H on Shopsmith's top 17: https://www.shopsmith.com/service/mostf ... dparts.htm) The quadrant should be centered and in line with the worm gear at all speeds.

Did you do a high speed adjust as Bill V mentioned? Among other things, this ensures that the speed indicated on the dial is approximately correct. The implied question is could you be at low speed but the indicator is not indicating that? One way to tell is to look at where the lower belt is riding in the Idler sheaves. At slow, it should be about 1/8" in from the outside of the sheaves.

Visually check the button bearing on the control sheave, and confirm that the clip is in the correct location on the speed control quadrant.

Confirm that your Idler shaft is properly retained in the headstock. Adjusting toward slow puts outboard pressure on the Idler. There should be a screw and washer in the casting that prevent the eccentric bushing from moving outboard, and another screw on the bushing to prevent the bearings and shaft from moving outboard. Sometimes one is missing. (Note - if you replaced the Idler shaft to replace bearings, your probably got the new version. IIRC SS requires that you use the new style of eccentric with it. I don't recall why or if that seems reasonable.)

You may need to confirm that the moving sheaves are still moving freely. This or a damaged speed control are the most likely causes.

- David