Shopsmith Forums

Ok folks, I just purchased a 37 year old Mark V. In order to get the headstock back on, I had to take the motor cover off, along with the belt cover, to adjust the locking mechanisms (please understand, my terminology is lacking, since this is my first Shopsmith) These same locking mechanisms were way out of adjustment.

Before I did this, I removed the four phillips head screws that attaches the motor, to the cover. So, I had to remove the drive belt from the lower drive belt sheave, in order to line up the motor to the motor cover.

So how do I get the drive belt, back onto the lower sheave?

Please advise, and thanks in advance.

PS: this drive belt, appears to be in great shape!
PSS: I am also happy that I did this, wow was there a lot of saw dust in there.
Lessons learned: do not remove the four phillips head screws.

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

I already watched this video, but it suggests that you do the "no-no" of adjusting the speed handle, without the motor running and I try and follow rules. Is there another way?

Once again, please advise!

Mount the large sanding disk on left or right end of the headstock depending on if you are left or right handed. Rotate the quill and therefore the sheaves (variable speed pulleys) using the disk. Is safer to slowly move the speed dial while rotating quill by hand.

Before you move anything, make sure the quadrant (the pork chop shaped arm) on the back is in position with the loop coming off the button in the control sheave the drive belt gets adjusted by is physically over the quadrant and past the spring steel detent on the other side.

The quadrant gets pulled open by this clip when you rotate the speed dial and pushed by the quadrant when rotating dial the other direction.


If you can't move sheaves by touching them directly, it is vital you have the pulleys and belts moving by hand when you do this. If it is not correctly on the pulleys you can tell. Turing on the motor to find it is not is always the wrong way to find out.

Search forums for Installing a Drive Belt and you will find member 'JPG' has a great series on how to do this with photos.

Sorry for any weird word substitution but my phone is losing its mind right now

When Jacob Anderson demonstrated how to do the process on it he is pushing down on the floating sheave surface just as the spring on the motor would if turning. Normally the belt cover would be on the machine and that would not be possible. What he demonstrated was fine as it was still moved by hand. Rotating it does it by spring safely as well. He needed in the fast position to make room at the top sheaves and make space to remove the belt and reinstall it between the surface and the quadrant and make it easy to reinstall the loop over th quadrant when done. Hope that helps.

everettdavis wrote:Mount the large sanding disk on left or right end of the headstock depending on if you are left or right handed. Rotate the quill and therefore the sheaves (variable speed pulleys) using the disk. Is safer to slowly move the speed dial while rotating quill by hand.

Before you move anything, make sure the quadrant (the pork chop shaped arm) on the back is in position with the loop coming off the button in the control sheave the drive belt gets adjusted by is physically over the quadrant and past the spring steel detent on the other side.

The quadrant gets pulled open by this clip when you rotate the speed dial and pushed by the quadrant when rotating dial the other direction.


If you can't move sheaves by touching them directly, it is vital you have the pulleys and belts moving by hand when you do this. If it is not correctly on the pulleys you can tell. Turing on the motor to find it is not is always the wrong way to find out.

Search forums for Installing a Drive Belt and you will find member 'JPG' has a great series on how to do this with photos.

Sorry for any weird word substitution but my phone is losing its mind right now

When Jacob Anderson demonstrated how to do the process on it he is pushing down on the floating sheave surface just as the spring on the motor would if turning. Normally the belt cover would be on the machine and that would not be possible. What he demonstrated was fine as it was still moved by hand. Rotating it does it by spring safely as well. He needed in the fast position to make room at the top sheaves and make space to remove the belt and reinstall it between the surface and the quadrant and make it easy to reinstall the loop over th quadrant when done. Hope that helps.

No damage is likely to occur by adjusting towards fast since this opens the control sheave. It is the other direction(towards slow) that damage can occur. Then the control sheave is 'closing'(squeezing the belt).

Since my last post to this thread, I have emailed Jacob Anderson asking him, for prices for both the drive belt and the Poly V belt. IMHO, if I have it all apart, I might as well, just replace them and if the others are still in decent shape, I will keep them for spares!

I also viewed his other videos entitled: Setting the Shopsmith Mark V speed control and Tensioning the Shopsmith Mark V Poly V Belt.

I do not see a video on the exact way to replace the Poly V Belt. So, I asked him in my email to him, if there was one!

As I understand it the damage caused by moving the speed dial with the shafts not moving is a result of the belt getting pinched and putting pressure on the gears.
So, if the belt is not installed yet, no damage should be possible even if the shaft is not moving.

rpd wrote:As I understand it the damage caused by moving the speed dial with the shafts not moving is a result of the belt getting pinched and putting pressure on the gears.
So, if the belt is not installed yet, no damage should be possible even if the shaft is not moving.

Yes. The warnings are relevant as the headstock is normally all buttoned up and the drive belt is in place. The fact the Poly-V belt isn't moving is not relevant when the drvive belt is off while you are working inside. When you put it back on you either have to rotate by hand which allows motor spring to press the motor floating sheave, or press it yourself as Jacob does in the video while looking at it when you need to rotate the speed dial with machine off.

When you consider the belts should last 10 years or more, lubrication and cleaning are the things you do most frequently.

Just a persnikity post to concentrate on the pertinent 'details'.

The reason for the "Do NOT Adjust Speed Unless Running" is that damage can be incurred. That damage is 'caused' by the control sheave squeezing the stationary motor belt. That resists further movement of the control sheave so that additional rotation of the speed control dial exerts increasing pressure on the worm gear and quadrant gear(porkchop). That can cause the distortion of the quadrant gear teeth and bending of the arm supporting the quadrant gear pivot.

That damage is minimized by the resultant increased belt tension causing the floating sheave to 'retract', thus relieving the control sheave 'squeeze'.

All that only occurs when adjusting towards slow.

Damage can be caused even with the pulleys rotating if adjustments(again towards slow) is done too rapidly(not giving the floating sheave time to react).

Tis easier to just say "don't" than to include all these picky details.

Yes, no belt, damage very unlikely.

I received an reply from Jacob Anderson and he quoted me prices for the belts and also mentioned that the bearings might need replaced.

It is true that he does not offer up a video, in replacing the Poly V Belt, because this involves a complete dismantle. He offers a complete DVD, for those who wish to do so.

Since then, I discovered that the quill had been upgraded to a two bearing setup and the belts were likely changed then too. (This might be why, the belts look to be in good shape) The fellow that was the original owner, was unable to run his SS Mark V for nearly 10 years,(he was on Dialysis and had very little strength to do so). Plus the unit was kept in a very dry, impeccably clean basement.

So, onto trying my hand with Jacob Anderson's method of installing the belt.

Thanks for your replies, as always!