Shopsmith Forums

greenhornet wrote:Upon further inspection of my machine and after taking out the quadrant assbly, I've made the following observations:

1. The speed-changing belt is 1/2" wide.

2. This belt, in the "fast" position on my machine, is just above the top of the floating sheave. I believe it is supposed to be within 1/16" of the top of the sheave, right? How do I adjust this? This means the floating sheave will hit the control arm of the "pork chop". Do I need to adjust the set screw, as in "adjusting the high speed setting" in the manual?

3. I've never replaced either belt and based on my measurements so far, I don't think the belt is the problem. Right or wrong?

Call me (anybody) if you can help.

Ray
757-2541071

Yes, it sounds like you need to do a High Speed Adjustment. This Sawdust Session covers what is required.

Let us get some terminology straight here!

The 'floating' sheave is the outer one on the motor shaft. It floats to maintain tension as the speed control is varied.

The other half is referred to as the 'fan' sheave. It does not move along the motor shaft and has the vanes for air circulation for cooling the motor. Hence the 'fan' designation.

The sheave which is moved by the speed control is referred to as the 'control' sheave. It moves along the idler shaft(the one in the middle between the motor shaft and the output(quill) shaft.

The other half is referred to as the idler sheave. It does not move along the idler shaft.

The speed control pork chop(quadrant gear) pivots on a roll(tension) pin inserted through two 'arms' extending into the headstock from the speed control mount. They have a tendency to get bent causing the wormgear to not mesh properly with the quadrant gear teeth.(I believe this is caused to some degree by turning the speed control down(to lower speeds) too fast. As a result of this mis-alignment, the teeth on the quadrant gear get damaged(the quadrant gear teeth are aluminum, the worm gear is steel).

I thought I had posted a link to a post describing this problem and one person's fix, but apparently I failed(forgot to 'submit'?) I will attempt to relocate it and add it to this post shortly. http://www.shopsmith.net/forums/showpos ... stcount=15

As Dusty has indicated the 'high speed adjustment' is necessary to ensure proper movement of various parts through their design intended range. For an initial setting, adjust the adjustment screw so the end is flush with the top of the jam nut. Do watch the sawdust session Dusty has provided the link for.

Ok, fellows, I've watched the sawdust session a couple of times now. I've also been able to "unbind" my machine. The sheave was hitting the lamb chop of the quadrant assbly. I was able to slowly turn the speed dial back down to a slow range, using a disc sander plate. I've not turned the machine back on, though, I've been able to freely turn the disc sander. When I get my new speed control handle, I'll put it on, turn the machine on, and do a "high speed alignment" on the machine.

Do you think I should go ahead and get a new quadrant assbly?

Ray