Shopsmith Forums

I am a newbie on this forum and a new owner of an inherited MKV.

The other day while using the table saw I had the speed set at the low end of saw-joint. As the machine ran I could hear and observe the speed increasing. I resorted to bringing the speed down to the magna-dado speed range so that the speed would maintain. I just had this cleaned and repaired by a friend who has done it many times, but if possible I would like to avoid putting it on his bench again.

Is there an adjustment or something that I can do without screwing things up that will prevent the speed creep?

Thank you

How worn is the motor belt? << 1/2"?

I am not sure on that, but my friend who repaired and cleaned it recently, had the blank authorization to replace anything necessary.

This opens up the question of WHAT prevents the belt tension from causing the force opening the control sheave from also causing the speed control dial from rotating.

I only see the porkchop bevel gear to worm gear resisting that. Or possibly the leaf spring under the control knob. A loose knob perhaps? Or a missing spring?. . . . .

The worm gear contact is essentially a line contact which would not impart a rotational thrust, however if the porkchop is skewed(a common wear condition) it might occur.

? ? ?

SgtIchy wrote: Wed Jun 01, 2022 6:03 am I am a newbie on this forum and a new owner of an inherited MKV.

The other day while using the table saw I had the speed set at the low end of saw-joint. As the machine ran I could hear and observe the speed increasing. I resorted to bringing the speed down to the magna-dado speed range so that the speed would maintain. I just had this cleaned and repaired by a friend who has done it many times, but if possible I would like to avoid putting it on his bench again.

Is there an adjustment or something that I can do without screwing things up that will prevent the speed creep?

Thank you

Does this mean that if the run speed was lowered then the speed did not creep up???

When the speed is creeping upward does the speed dial change position???

If you do not intervene will the upward creep continue or does it eventually cease to creep???

Right, not clear if the speed dial is changing position. If it is not then I think JPG has the right idea in looking at the lower belt. If the speed dial is moving an issue with the quadrant should be observable from the back nameplate opening, with a disk sander mounted instead of a saw blade for safety reason and practicality.

dusty wrote: Wed Jun 01, 2022 11:16 am

SgtIchy wrote: Wed Jun 01, 2022 6:03 am I am a newbie on this forum and a new owner of an inherited MKV.

The other day while using the table saw I had the speed set at the low end of saw-joint. As the machine ran I could hear and observe the speed increasing. I resorted to bringing the speed down to the magna-dado speed range so that the speed would maintain. I just had this cleaned and repaired by a friend who has done it many times, but if possible I would like to avoid putting it on his bench again.

Is there an adjustment or something that I can do without screwing things up that will prevent the speed creep?

Thank you

Does this mean that if the run speed was lowered then the speed did not creep up???

When the speed is creeping upward does the speed dial change position???

If you do not intervene will the upward creep continue or does it eventually cease to creep???

When I set the speed at "P" I was able to observe the control dial move and hear the RPMs increase. I dialed it back when it achieved "S". I am not sure if it would have continued beyond that. When I backed it off to the magna-dado speed, it remained where I set it.

My Shopsmith did a similar thing a couple of months ago. The speed was creeping up as it ran, but I could also hear a clicking sound inside it. I shut if off, pulled the plug from the wall, and removed the side cover. Then, when turning it slowly by hand, I could hear the clicks and see uneven movement in the control sheave. The small bearing in the end of the control sheave was bad. I replaced the bearing and it is quiet now and no longer seems to creep. Yours could be an entirely different problem, but some visual inspection might show you the problem. The bearing I replaced is in the end of part 110 on the diagram.

I think you might be on to something there.

If the end of the control sheave is missing or has a damaged bearing and 'button' the porkchop might be experiencing pressure greater than 'normal'.

Thank you for all of the replies! I checked this again and was able to verify that when I run it having set the speed control at "M" (in the center of the Magna-Dado range) over the span of a minute or so, the speed creeps all the way to the "W". When the speed is set below the "M" the speed holds steady. As the RPMs increase you can watch the dial move.