Issue with my Mark 5

[dfield]

Hi I'm new here, this is my first post. I searched a bit on this forum but didn't see my particular issue. Hopefully this question isn't asked over and over.

My Shopsmith starts up and runs fine. The speed control appears to function properly. When using the table saw configuration, the blade spins fine until I start cutting. As soon as I start cutting, the blade stops turning even though the motor is still running. I have taken the headstock apart and cleaned and oiled it so shouldn't be any issues there.

Any thoughts on what the problem might be?

Thank you,

Dave

[garys]

When you have the side cover off, take a look at the pulleys and belts. The problem will most likely be obvious.

Them that turns is good, them that doesn't turn is bad!

[DLB]

Welcome to the forum. Adding to what garys said, it is useful if you provide the age or configuration of the machine. There is a lot of difference between what would cause this on an older machine with Gilmer upper belt (usually a Greenie) and what would cause it on a 'newer' machine with a Poly-V upper belt. If it is a Gilmer a slipping clutch is likely. If it is a Poly-V, start with belt tension. This is a 1960's change, essentially 100% difference in possible causes of slipping.

- David

[SteveMaryland]

Yes, check the belts, check that oil lubricant has not gotten on belts or sheaves.

Check that the saw blade arbor nut is tightly holding the blade. Check that the arbor setscrew is facing the flat on the main spindle shaft and bears firmly on that flat.

[Hobbyman2]

Any out of place noises or smells when it slips ?

[beeg]

Is the blade sharp? Mounted correctly? Not feeding the wood to fast?

[dfield]

Thanks for the replies. I bought the shopsmith new in 2005. I will take the side cover off this weekend and inspect the belts. I don't recall any odd noises when encountering the problem. Maybe I will do a test run before inspecting the belts and listen for odd noises. I will also check the blade arbor and sharpness too.

[chapmanruss]

Dave,

Let me add my welcome to the Shopsmith Forum. The others have given some common causes already. I would suspect that the upper belt is worn and stretched a bit being 16 years old and needs to have the tension adjusted. Since you bought your Mark V new in 2005, I would guess you have the Manual for it. Check the Maintenance and Troubleshooting section for Checking Belt Tension and follow the steps for adjusting that. In my Mark V 520 Manual Rev. 3/99 that starts on page D-4. It is a fairly simple adjustment and do take note of the condition of the belts. This would also be a good time to lubricate the pulley sheaves while you have it open if that has not been done in a while. It is the upper Poly V belt that more commonly slips but if the movable sheave of the motor pulley isn't properly lubricated it could start sticking and not keep tension on the lower belt as the speed is adjusted.

Another possible related cause as beeg suggested could be a dull blade. It would be harder to cut with a dull blade causing belt slippage. The same with feeding the wood being cut too fast.

[dfield]

Thanks for the great information. I will break out the manual this weekend and read through the section that you suggested. I doubt it's the blade but I will check it. My Shopsmith hasn't seen heavy use so the blade is probably good. I did open up the headstock and clean and oil it based on a video I found on Youtube.

Dave

[AEA]

This something I'm not real proud to share.
One day I was getting ready to rip some 2 x 4 in half. I put the lower guard on and a rip blade. I couldn't see the set screw to tighten the blade so I got a spare put it in and tightened it down. I then set the table into position and put on the upper guard, set the fence and was ready to cut. I turned on the machine and set the speed, everything was fine until I started to feed the board in. The blade stopped, the motor kept running like there were no issues at all, no belt squeals or anything.
When I removed the upper guard and got the table out of the way I could move the blade by hand even though the set screw was tight. I took out the set screw I had put in earlier and discovered there was another one in there already, so the only thing I did was tighten a set screw to another set screw.
I felt real stupid and relieved that nothing bad happened and it was easy to fix. (I no longer use the real short set screw on the saw arbor)