Speed Control Binds - Saw Slows

[80spiders]

Watched a demo on SS web site and the suggestion was made to use the quill to make fine adjustments rather than bumping the fence in for a small dimensional change.
I tried this and it was not long...maybe 45 sec of run time - and i wanted to turn the machine off to get another piece of wood to cut. As i was lowering the speed (slowly), the control dial got stiffer and stiffer and then froze. Also, the saw blade seemed to slow down dramatically as well.
Pulled the cover, oiled where i should, put the sanding disk on so i could rotate the shaft to see if the speed control dial would free it self...and it did. Everything appeared to operate as designed.
Put the cover back on and the saw blade. Made a few more cuts without the quill extended and all was fine.
Then, assuming the problem was corrected with the oiling, added a dado blade and used the quill extended suggestion for minor dimensional changes and the same problem occured.
I did not reoil but placed the sanding disc on the headstock and turned the mechanism by hand. As before, the speed control dial had frozen but now freed itself. I finished the job without the quill extended with no issues. I even ran the speed up and down several times and the speed changes were smooth.
What the heck could be the problem with the quill extension causing this binding of the speed control dial and an apparent load on the motor but only temporary?

[chapmanruss]

That is a curious problem. I cannot explain why this would happen since the Quill is a different part of the entire drive system. Extending and retracting the Quill should not have any effect on the Speed Control Assembly's ability to function properly. Lack of proper lubrication of the Speed Control and pulley sheaves of the motor and Idler shafts are generally the most common problem followed by damage to the gear teeth of the Speed Control assembly. Since you are doing some maintenance anyway, I would suggest removing the Quill from the Headstock for inspection. Check that the bearing(s) turns freely and clean and rewax the Quill if needed.

When you said

As i was lowering the speed (slowly), the control dial got stiffer and stiffer and then froze. Also, the saw blade seemed to slow down dramatically as well.

Do you mean the blade slowed faster than the Speed Control Dial was turned down?

[80spiders]

Yes, i think the blade slowed more than it should given the few turns allowed on the speed control before it froze.

[DLB]

Yes, i think the blade slowed more than it should given the few turns allowed on the speed control before it froze.

I'm with Russ, no single obvious thing that could cause all the symptoms. For speed control binding and the excessive slowing in combination, this can happen if the lower belt gets too deep into the sheaves where it is no longer a "V." I think it can only happen with a worn or undersized (width) belt. The rule of thumb is that the widest part of the belt should be a minimum of 1/2". But I can think of no correlation between this and the quill location.

I pretty much always run as you describe, with the quill slightly extended, and have never had a problem related to it.

- David

[dusty]

Is there any reason for why the quill could not be removed while testing the speed control?

If you consider doing this be aware that the quill spring could rapidly become an issue. Do not let the quill spring unwind!!!

Clarification Please. What freezes? The speed control or the drive shaft or something else???

[80spiders]

It is the speed control dial that gets stiffer and stiffer and the freezes around letter L.

[JPG]

Stiff control changes towards slow is usually the result of the control sheave squeezing the belt and the floating sheave NOT responding by opening the motor pulley to provide reduced belt tension. A lagging response when adjusting towards fast and slowdown of quill shaft is caused by the floating sheave not responding by opening the motor pulley.

BOTH behaviors are caused by inadequate lubrication of the floating sheave on the motor shaft(or gunk). Solution is cleaning the sheave bore and shaft and lubrication.

I think the quill extension is a red herring.

[80spiders]

I would like thank Russ, David, Dusty and JPG for your input on this. I have reapplied oil and hit the pork chop with some dry lube. I used it some over the weekend with no more issues - hoping the speed control binding during slow down is now resolved and just a coincidence with the quill extension. Speed control is a lot smoother now to operate up and down.

[dusty]

I would like thank Russ, David, Dusty and JPG for your input on this. I have reapplied oil and hit the pork chop with some dry lube. I used it some over the weekend with no more issues - hoping the speed control binding during slow down is now resolved and just a coincidence with the quill extension. Speed control is a lot smoother now to operate up and down.

This is good to hear. Just to be sure - I would suggest that you oil the sheaves once again. The only damage done by a little too much oil is that it gets spread around the inside of the casting.