control sheave stuck

edcisco · Post by **edcisco** » Mon May 03, 2010 1:26 pm

I am near Greensboro, NC and just bought a used Mark V 1986 vintage and the speed control does not work. I found the wire loop was off along with the roll pin down under the motor. I got it back on but because the control sheave is stuck tight, when I start motor and turn speed control handle, it doesn't move. I removed speed changer(pork chop etc) and removed drive belt. The sheave is stuck in the slow position. I have looked at the procedure for removing the gilmer belt and shaft, but would like to get the control sheave unstuck without taking anything else apart. Is that possible without a big hassle? The motor sheave moves back and forth on its shaft just fine. I have found the oil hole on the control sheave shaft and oiled it last nite and am letting it set. Since you guys have done a lot of this, what is my best approach now.

thanks,

Ed

JPG · Post by **JPG** » Mon May 03, 2010 1:38 pm

Although it may loosen up after 'soaking', it probably needs a thorough cleaning/lubrication. With the speed control etc. out of the way, it should pull off the shaft. This is easier working from the bottom(with the ways raised to vertical). That means drop the motor. Five screws and a power switch and it comes off.

It really needs to come out(it is not all that difficult with the motor out) and is far easier to work on 'in hand'!

Besides it will be an 'educational' experience.

beeg · Post by **beeg** » Mon May 03, 2010 1:56 pm

A 1986 MArk V wood have a poly-v belt. Knot a gilmer belt.

edcisco · Post by **edcisco** » Mon May 03, 2010 3:01 pm

I'm not familiar with what they are called, but I think both belts had been changed by the previous owner.
thanks,
Ed

edcisco · Post by **edcisco** » Sat May 08, 2010 8:40 pm

OK, I took your advice and removed the complete idler shaft assembly from the machine. The contol sheave is still stuck solid on the shaft in the low speed position. I have tried using wooden wedges to drive the sheaves apart with no luck. I have sprayed the whole thing with PB blaster which is supposed to loosen up stuck bolts, etc. and will try again tomorrow. Is there an easier way?
thanks,

Ed

heathicus · Post by **heathicus** » Sat May 08, 2010 9:45 pm

Try Kroil. I haven't tried PB Blaster, but I've tried Liquid Wrench and there is no comparison.

http://www.kanolabs.com/

dusty · Post by **dusty** » Sun May 09, 2010 6:50 am

edcisco wrote:OK, I took your advice and removed the complete idler shaft assembly from the machine. The contol sheave is still stuck solid on the shaft in the low speed position. I have tried using wooden wedges to drive the sheaves apart with no luck. I have sprayed the whole thing with PB blaster which is supposed to loosen up stuck bolts, etc. and will try again tomorrow. Is there an easier way?
thanks,

Ed

There might be an easier way but the chances of it costing money are high.

Patience must prevail!! With the idler shaft completely removed you are in the best position to work of this problem. Force and hammers are out. Wedges and fingers are okay.

What you are working to overcome is the direct result of inadequate cleaning and lubrication. A regular preventive maintenance schedule is a must to prevent a repeat of this ordeal.

8iowa · Post by **8iowa** » Sun May 09, 2010 9:03 am

The control sheave bearing is a top candidate for the Headstock's weakest point. The roll pin and loop coming off is usually an indication that the bearing is failing.

dusty · Post by **dusty** » Sun May 09, 2010 9:43 am

8iowa wrote:The control sheave bearing is a top candidate for the Headstock's weakest point. The roll pin and loop coming off is usually an indication that the bearing is failing.

Yup. I bought a Control Sheave Assembly (515556) many moons ago because it was one of the 17 Most Frequently Ordered Shopsmith Parts and I am still waiting to have a real need for it. I have become a firm believer in proper lubrication. Maintain a schedule for preventive maintenance and a Control Sheave may never be needed.

BTW, I believe that referring to the Control Sheave as a "weak point" may be misleading. Yes, it is a point adversely effected by inadequate care. Call it "most abused" maybe but not a "weak point".

wa2crk · Post by **wa2crk** » Sun May 09, 2010 9:59 am

Ed;
As the others have said regular lubrication is VERY important. I have posted my schedule for maintenance before but here it is again. SS says to lube twice a year so there two occasions to have a "party" with your machine. New Years day and the 4th of July. These two holidays are 6 months apart so it is a good schedule. This recommendation is only for normal use. If you do a lot of lathe work or sanding you should lube more often.
Bill V