Speed Control Middle Setting, No Power, Maintenance Required

[Tyler]

I recently bought a Mark V 1982. It hadn't been turned on in years according to the PO (10+). We plugged it in and fired it up to make sure it worked before I bought it. I didn't want it to run for long because of how long it had been sitting, so we took the speed from A to E and then switched it off.

Before I bought I did notice the ground prong was missing on the cord (snapped off presumably). First order of business upon getting the thing home was to clean it up and oil it.

I cleaned it up, oiled it per youtube, replaced the plug and flipped it on. Power ran to it, but it wouldn't turn. I powered it off, read some from this great forum, and disassembled the unit to give it a thorough cleaning.

Here is where I might be in trouble. It was so dirty I ended up taking off the drive belt, and unmounting the motor so I could really clean it. After cleaning, I ran the motor without a load and it runs beautifully.

I noticed upon disassembly that the quadrant appeared to have melted at parts. The little metal shield was completely worn through. So I haven't reassembled because I need to replace the part.

Here is the crux of my question. The unit was last powered off at speed E. I need to know:

1. Can I replace the speed control assembly and just put it all back together at the same speed position E and be fine?

2. Without a drive belt attached and without power, does adjusting the speed still do damage? (I have avoided doing this, just curious)

3. If the speed control wasn't in low or high when disassembled, how do I recalibrate it without screwing it up?

I measured the width of the drive belt and it needs to be replaced, so let's throw that wrinkle in there as a requirement before I can turn it back on.

[reubenjames]

The speed is based on the relation of the belt relative to the two pulleys, which changes due to the floating sheaves controlled by the quadrant. In other words you are effectively changing ratios like gear ratios in a vehicle.
Once the belt between the two pulleys is removed, the speed you were at last time you shut it off becomes irrelevant. You can't remove the belt fully from the headstock without disconnecting the speed control. You can thus safely turn the speed crank at that point and indeed should pull and clean and inspect it or replace it, it sounds like. You can also freely move the pulleys and check for proper operation and lubrication there. The "speed" you are at after replacing the belt (go ahead and replace both belts on a machine that old and sitting that long) is determined by where the belt is resting in relation to the sheaves, as before. Practically speaking, due to the spring on the sheaves attached to the motor, you will be installing the belt in a high speed position. Check out Nick Englers videos from the last few Sawdust Sessions where he replaces belts and performs a high speed adjustment. That is the whole procedure you are after. Also, while everything is already in disarray, be sure to check all bearings while in there and replace as necessary. 30 years is a long time and 10 years idle isn't usually a good thing. On the plus side, I think the headstocks from the 80's hit a sweet spot with the motor and components (like the good idler shaft bearings) they used. Spend some time with her now and you'll easily get another 34 years out of her.

[reubenjames]

The last four sawdust sessions will be useful to you, but this one in particular to your immediate question
http://www.shopsmithacademy.com/SS_Arch ... rn_Pt3.htm

[Tyler]

Thank you so much! All the info you provided was super helpful.l and exactly what I was looking for.

[reubenjames]

You're welcome! Take pictures and ask questions along the way and the people here who are smarter than me will help. Welcome to the forum and the ShopSmith family!

[JPG]

The quadrant gear is more likely 'mashed' rather than 'melted'.

The legs that the quadrant gear mounts on are likely bent as well(common cause).

Common problems caused by improper adjustment of speed towards slow(sedately is good, rapidly is bad).