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loose belt/speed control problem

Posted: Sun Feb 17, 2013 3:09 pm
by saminmn
So what did I do wrong and what now?

I was planning on making a bunch of Ed's red, white and blue whirligigs (Stars and Kites Forever, no no that is not right), but decided to lube motor before starting.

I put on a sanding disk and manually advanced the control speed while turning the sanding disk. When I removed the covers to put in oil I noticed that the v-belt was loose and now, after oiling, I am having trouble getting the speed control to go back to slow - still moving it manually.

Posted: Sun Feb 17, 2013 3:32 pm
by wa2crk
The floating sheave may be stuck on the motor shaft. As you go to a higher speed the motor sheave gets larger and if it sticks along it's travel and you further toward to "fast" The control sheave gets smaller and the belt gets loose. Try to move the floating sheave and see if it is sticking.
Bill V

Posted: Sun Feb 17, 2013 3:47 pm
by saminmn
I guess it just took more force to turn the speed control for slowing than I remember doing when I cranked it up to fast. Anyway it works now. I cranked it down manually. Then I turned it on and went up an down on speed a couple of times. Everything sounded fine. Thanks for reply.

Posted: Sun Feb 17, 2013 8:39 pm
by charlese
Time to do a oil (lube) job on both sheaves. Yes the resistance is greater when turning speed control down.

Not only speaking to criticize, but to preach to the forum in general.

Yes, I'm preaching, but It is a lot easier on your machine if you keep the control sheave and motor sheave well oiled. It seems to me that many guys forget to adequately lube the motor sheave. The belt way to do this is to put the unit into drill press position and oil not only that little hole, but also drip some oil onto the motor shaft (through the spring) and let it flow down toward the motor and into the slide.

Remember that after oiling both sheaves to run the speed all the way high and back to low at least five times.

Posted: Sun Feb 17, 2013 11:50 pm
by saminmn
charlese wrote:Time to do a oil (lube) job on both sheaves. Yes the resistance is greater when turning speed control down.
:) Well, that was what I was doing, oiling the sheaves. Don't know that I was particularly tardy on this maintenance.
Not only speaking to criticize, but to preach to the forum in general.

Yes, I'm preaching, but It is a lot easier on your machine if you keep the control sheave and motor sheave well oiled. It seems to me that many guys forget to adequately lube the motor sheave. The belt way to do this is to put the unit into drill press position and oil not only that little hole, but also drip some oil onto the motor shaft (through the spring) and let it flow down toward the motor and into the slide.

Remember that after oiling both sheaves to run the speed all the way high and back to low at least five times. I ran it up and down, but not 5 times, will run it up and down the speed range a few times.
Thanks for preaching. I am still getting used to the idea that ShopSmith's recommendations on how much oil to use is probably best ignored.:D

Posted: Mon Feb 18, 2013 1:26 am
by JPG
Adjusting up is always easy because the control sheave is decreasing the belt tension. The floating sheave on the motor pulley must relieve the increased belt tension applied by the control sheave when adjusting the speed downward. That is the reason to not adjust the speed downward unless the pulleys are turning.

When doing so manually, turn the speed control downward until it binds, then spin the pulleys until the floating sheave moves out. That will relieve the belt tension and the sequence may be repeated. It is not necessary to continually spin the pulleys unless you are also continually adjusting the speed control. Going up in speed does not need the pulleys moving, but going too far can let the belt drop down between the control and the idler sheave.

Posted: Mon Feb 18, 2013 2:01 am
by saminmn
JPG40504 wrote:Adjusting up is always easy because the control sheave is decreasing the belt tension. The floating sheave on the motor pulley must relieve the increased belt tension applied by the control sheave when adjusting the speed downward. That is the reason to not adjust the speed downward unless the pulleys are turning.

When doing so manually, turn the speed control downward until it binds, then spin the pulleys until the floating sheave moves out. That will relieve the belt tension and the sequence may be repeated. It is not necessary to continually spin the pulleys unless you are also continually adjusting the speed control. Going up in speed does not need the pulleys moving, but going too far can let the belt drop down between the control and the idler sheave.
Makes sense. I had come to that conclusion when I was re-checking belts, sheaves, and thinking out the speed change function after wa2crk responded. Very neat system.

Posted: Mon Feb 18, 2013 11:22 am
by terrydowning
charlese wrote: The belt way to do this is to put the unit into drill press position and oil not only that little hole, but also drip some oil onto the motor shaft (through the spring) and let it flow down toward the motor and into the slide.

Remember that after oiling both sheaves to run the speed all the way high and back to low at least five times.
I let mine sit over night to really seep down in. Don't forget to fashion a shield out of cardboard, plastic, sheet metal, or whatever. Excess oil does get slung/flung at high velocity and it will go all over your shop and you if you're not careful DAMHIKT! It's a self teaching lesson but if anyone can benefit from my mistake, they're welcome to it.

Posted: Mon Feb 18, 2013 8:05 pm
by charlese
saminmn wrote:Thanks for preaching. I am still getting used to the idea that ShopSmith's recommendations on how much oil to use is probably best ignored.:D

No - not ignored! just exceeded!!! A little extra won't hurt a thing, unless like terrydowning you get excess oil thrown where you don't want it.

I finally learned to put the belt cover back on before running the speed up and down. Then sliding the cover back and wiping the inside down.