Shopsmith Forums

I have a Mark V that has been running great but recently I put it to the test and made very deep cuts in some hardwood. Now when I turn the speed control the speed ramps up very slowly and I must go until at least "saw" speed for it to change. Once up to speed I can reduce it as per normal. I've cleaned and oiled what I can but it still ramps up slowly. I've been searching past Q&A but haven't found what I'm looking for. Thank you

I don't know! But I have a couple ideas. First, a question. When you are turning the speed dial, I believe you are saying you do not sense a change in speed until you get to "saw speed". Is this correct and if so, does it then increase speed normally.

Have you opened it up so that you can see the sheaves? If so, do they change smoothly as you turn the dial? I suspect NO.

Before I would turn the speed control rather slow and the speed would ramp up as I turned the control. Now I turn it as slow but have to wait for the shaft to come up to speed. If I count it off in my head it seems like from the time I have it at saw speed it takes another 4-6 seconds on top of the few seconds it took to get to saw speed. After I cleaned and oiled everything I ran the machine up and down the dial with the outer case off so I could see the belts. The upper belt seemed to angle (not stay in line) part of the time and the shaft below moved in and out.

I really appreciate your help I just hope I'm describing this right.

beerboss wrote:Before I would turn the speed control rather slow and the speed would ramp up as I turned the control. Now I turn it as slow but have to wait for the shaft to come up to speed. If I count it off in my head it seems like from the time I have it at saw speed it takes another 4-6 seconds on top of the few seconds it took to get to saw speed. After I cleaned and oiled everything I ran the machine up and down the dial with the outer case off so I could see the belts. The upper belt seemed to angle (not stay in line) part of the time and the shaft below moved in and out.

I really appreciate your help I just hope I'm describing this right.

More discussion needed here. The "shaft" should not move and the belt should remain vertical.

What model are we discussing; Model 500, Model 510, etc.

500. I'll get more specif information tonight and hopefully I can figure out how to post a photo or better yet a video.

I never noticed it before but the hub (exterior) of the lower shaft moves in as I turn up the speed control.

When you oiled it, did you include the lower(motor shaft) sheave?

What you describe is usually a reluctant(slow responding) floating sheave(the hub that moves)on the motor shaft. Did you place oil into the hole under the spring?

Do not be stingy with the oil and make sure it gets to the shaft.

Adjusting towards slow, the belt is forcing the sheave. Adjusting towards fast, only the spring is causing the sheave to move(the belt is slackening).

On the lower shaft I used a screw driver to expose the hole in the shaft and oiled it, let is soak and repeated a few times. Inside the housing I took a tooth brush and cleaned off the quadrant shaft (?)and screw drive and oiled the hole on the shaft. That is I directed the 3m spout through the name plate opening and put the tip in the hole.

Could I have glazed the sides of the belt or doesn't that matter?

beerboss wrote:On the lower shaft I used a screw driver to expose the hole in the shaft and oiled it, let is soak and repeated a few times. Inside the housing I took a tooth brush and cleaned off the quadrant shaft (?)and screw drive and oiled the hole on the shaft. That is I directed the 3m spout through the name plate opening and put the tip in the hole.

Could I have glazed the sides of the belt or doesn't that matter?

Maybe, but that would likely cause slipping(low torque).

Run it up to fast. Reach in and pull on the floating sheave. You should be able to pull the sheave out(open the pulley) fairly easily.

Stop it first!!!! If you can get it open and it wants to stick open, apply oil directly to the shaft between the sheaves.

More than likely disassembly and a thorough cleaning will be required of the lower shaft movable parts. Good idea to do the same on the control sheave as well.

Thanks, I'll give it a shot. I think I will take it apart, it has been a few years since I revived it anyway.

beerboss wrote:Thanks, I'll give it a shot. I think I will take it apart, it has been a few years since I revived it anyway.

Beware that spring!!!!!

Research the removal(and reassembly) method before attempting.