Old Mark VII speed control issue.

[Winginsue]

So I just got this old Mark VII from a guy. Used it to do some turning on the lathe at low speed. A couple times I noticed that when I turned it on the spindle didn't turn. If I turned the speed up a notch then back down it worked. No biggie.

Here's my problem. I decided it was time to oil it. Following the manufacturers instructions in the owners manual (yup, it came with it) I plugged it in, turned it on and turned it up to router. Turned it off to oil it. Okay. Good so far. Turned it back on.

1. Noticed the spindle wasn't turning.
2. As I turned the speed controller, around the time I got to Dado, it's becoming hard to turn and the machine is making some whining noise. I get to Drum and it won't turn any further. The machine sounds like it's working hard and poof it blows the fuse.

I contacted the seller. He said the shims likely got buggered up. I am quite mechanically inclined BUT am a bit nervous about trying to take them apart to see if I can fix them since I have no manual to refer to.

Any helpful suggestions would be greatly appreciated. I'm sure this can be fixed. I just am at a loss to figure out how at this point.

Thanks bunches.

[Winginsue]

Update. I see what the issue is. I think I can figure out how to repair it. It's not cams in the controller, it's how the belt is on the wheels.

[lahola1]

I have an old mark VII. I don't know what the seller is talking about shims being buggered up. I don't know of any shims on it.

Sounds to me like spring loaded sheave on the motor isn't moving (opening up) as you slow down the speed.
There are 3 screws holding the back headstock cover on. Remove them and see if you can pull the sheave back against the spring. If you can't, it is already back all the way or it's dry and needs oil.

[lahola1]

It's also possible the upper sheave is dry and not moving with the cam pressure.
DON'T force it! That's how you break things; some almost irriplacable (Can't spell) on this machine. (not supported by SS.

[JPG]

Yes I think the PO was referring to the sheaves, not shims.

Did you oil BOTH the control shesve AND the floating sheave on the motor shaft?

Good advice above re forcing.!!!

When the speed control knob is turned towards slow, the control sheave is closing(squeezing the belt) and the floating sheave MUST open up to release that squeeze. That is why turning the speed control knob with the pulleys not rotating is a no-no. Same reason as with a Mark 5/V.

Do not be stingy with the oil.

[Winginsue]

Thanks for all your assistance. After disassembly I found that one of the bearings was seized on the upper set of sheaves. In getting that out of the housing the part that rides against the SINGLE cam broke off. I think the metal was just worn out. I found a used Mark V that I got which works fine. It was heartbreaking getting a machine that didn't work but I'm happy now. I did get the jointer and bandsaw with the first one so I can't complain much.

[garys]

You did the right thing. Disassembly and inspection usually shows you what is causing a problem like this. Now if you can get the correct replacement parts, you can have it running like new again.

[JPG]

Thanks for all your assistance. After disassembly I found that one of the bearings was seized on the upper set of sheaves. In getting that out of the housing the part that rides against the SINGLE cam broke off. I think the metal was just worn out. I found a used Mark V that I got which works fine. It was heartbreaking getting a machine that didn't work but I'm happy now. I did get the jointer and bandsaw with the first one so I can't complain much.

So now you have a MV and a MVII(that doesn't work)?