Newly acquired 510 - Control Sheave not moving

[sssteve]

Ok, have a problem. I cleaned all the components in the headstock, and was able to get the control sheave loosened. After getting it back together, I started the motor and was able to change the speed from slow to high and then back to slow several times. Then going from slow speed back to high I heard a pop. Turned off the motor and looked in the nameplate access hold. Here is what I saw.



During the cleaning and oiling of the idler shaft and control sheave, I had noticed that the vanes of the control sheave seemed to bind/rub against the vanes of the idler sheave. Being that this machine is 20 years old and these parts were original, and had worked fine according to the previous owner, I put it back together. I now believe that the control sheave got stuck again due to the vanes rubbing/binding to the idler sheave vanes, and then the bearing pulled out of the control sheave unit when trying to increase the speed.

Do I now need to get a new Control Sheave, or is there a way to get the bearing back into the control sheave? I have also included photos of the speed changer dial teeth and the gears on the speed control assembly. Looking for some guidance on my next move.

[JPG]

Ok, have a problem. I cleaned all the components in the headstock, and was able to get the control sheave loosened. After getting it back together, I started the motor and was able to change the speed from slow to high and then back to slow several times. Then going from slow speed back to high I heard a pop. Turned off the motor and looked in the nameplate access hold. Here is what I saw.

http://www.shopsmith.net/forums/attachment.htm?attachmentid=11212&stc=1&d=1292456924

During the cleaning and oiling of the idler shaft and control sheave, I had noticed that the vanes of the control sheave seemed to bind/rub against the vanes of the idler sheave. Being that this machine is 20 years old and these parts were original, and had worked fine according to the previous owner, I put it back together. I now believe that the control sheave got stuck again due to the vanes rubbing/binding to the idler sheave vanes, and then the bearing pulled out of the control sheave unit when trying to increase the speed.

Do I now need to get a new Control Sheave, or is there a way to get the bearing back into the control sheave? I have also included photos of the speed changer dial teeth and the gears on the speed control assembly. Looking for some guidance on my next move.

http://www.shopsmith.net/forums/attachment.htm?attachmentid=11213&stc=1&d=1292457330
http://www.shopsmith.net/forums/attachment.htm?attachmentid=11214&stc=1&d=1292457526

I am not hearing anything regarding the motor shaft pulley(floating sheave).


If the floating sheave is not 'responding' quickly enough, the porkchop(quadrant gear) will pull on the loop. It should not need to pull on it! The spring on the motor shaft should force the floating sheave in so as to incease the effective pulley diameter. That will in turn force the control sheave to open up(it follows the porkchop as it moves away from the end of the control sheave 'snout').

If the vanes on the control sheave and the other half of the idler pulley are rubbing/interfering, the keyway in the control sheave and or the key may be worn.

At this point I would recommend removal of the idler shaft and pulley in order to determine the condition of the key/keyway. This would allow you to determine what if anything can be done with/to the loop bearing.

If the keyway is worn, the loop bearing becomes moot! The control sheave(and key) need to be replaced. A new snout bearing will come with it!

Regardless, the floating sheave/motor shaft must be operating properly.

[billmayo]

[quote="sssteve"]During the cleaning and oiling of the idler shaft and control sheave, I had noticed that the vanes of the control sheave seemed to bind/rub against the vanes of the idler sheave. Being that this machine is 20 years old and these parts were original, and had worked fine according to the previous owner, I put it back together. I now believe that the control sheave got stuck again due to the vanes rubbing/binding to the idler sheave vanes, and then the bearing pulled out of the control sheave unit when trying to increase the speed.

Do I now need to get a new Control Sheave, or is there a way to get the bearing back into the control sheave? I have also included photos of the speed changer dial teeth and the gears on the speed control assembly. Looking for some guidance on my next move.[quote="sssteve"]

You will need to disassemble your headstock to check where any binding is occurring. I find that the Control and Idler Sheaves vanes tips will flatten out if the speed is operated at the same speed over time (like set up for table sawing) to where the vanes tips will stick when the sheaves are in the closed position (together). Also manufacturing tollerances when machining the keyway will allow new sheave vanes to be closer on one side of the opposite vanes so the vanes will stick when the vane tips start to flatten. The ID of the Control and Floating Sheave varies so a new and/or replacement sheave may stick on the idler or motor shaft.

I find I have to do a mix and match on both the Control and Idler Sheaves along with the motor Fan and Floating Sheaves to insure the sheave vanes are located in the center of the opposite sheave for either set of sheaves along with not sticking on the idler/motor shaft. I try to only used matched sets of sheaves when replacing any sheave. I recondition the sheaves to remove any vane tip flattening these days.
[ATTACH]11215[/ATTACH]

There are several Forum members who can install the Control Sheave bearing including myself. I ask for the Speed Control Assembly, Control Sheave with bearing, button and retaining loop and the complete Idler shaft assembly to be shipped to me so I can insure all the parts will fit and work smoothly when installed again.

[ddvann79]

Steve,

Very sorry to hear about your plight. I'm sure you weren't expecting this kind of maintenance right off the bat but don't get discouraged. It seems too many ShopSmith owners neglect regular lubrication that causes this kind of thing . From what I've read on this forum, the bearing in the control sheave is one of the few things in a SS you want a pro to repair (unless you have the right equipment).

At least you got such a good deal on the rig you still have some room in the deal!

[rp2485]

I have just inherited a Mark 5. The previous owner passed away before he could have put more than a dozen hours on it. To bring it home, the unit sat outside for a couple of hours, an hour in the back of my truck and a day in my garage. With the tight tolerances of the two shafts with the movable clutches, the motor would not turn the shaft because of minute traces of rust on the shafts. Blown fuses etc. I took off the back cover, put the machine in the drilling position, opened up the SS label cover and used a LOT of silicone and WD40 on the shafts. I would have to put it at low speed or open the clutch on the motor in order to get it started. After a couple of days, it now starts at the "Saw" speed without hesitation. Life goes on without having to do any major teardown. Good luck.
Arnprior, Ontario, Canada

[JPG]

I have just inherited a Mark 5. The previous owner passed away before he could have put more than a dozen hours on it. To bring it home, the unit sat outside for a couple of hours, an hour in the back of my truck and a day in my garage. With the tight tolerances of the two shafts with the movable clutches, the motor would not turn the shaft because of minute traces of rust on the shafts. Blown fuses etc. I took off the back cover, put the machine in the drilling position, opened up the SS label cover and used a LOT of silicone and WD40 on the shafts. I would have to put it at low speed or open the clutch on the motor in order to get it started. After a couple of days, it now starts at the "Saw" speed without hesitation. Life goes on without having to do any major teardown. Good luck.
Arnprior, Ontario, Canada

I would now suggest flushing the wd-40 and silicone out and replace it with 10w machine oil. If not now, very soon!

[sssteve]

I pulled the idler shaft out and fiddled with the Control Sheave again. The Control Sheave slides freely on the idler shaft, but as mentioned before, the Control Sheave is binding against the Idler Sheave as can be seen in the photo.



It takes a little effort to get the sheaves apart after they have made contact with each other. Ordering a new Control Sheave does not mean that this would not happen with a new one. Someone has provided an option of sending them the sheaves and they would provide a good match. Another option with some cost would be ordering a new idler shaft assembly (including a new control sheave). Just checking to see if there are anything that I could do yet to get around this before proceeding with one of the options mentioned above.

[dusty]

I pulled the idler shaft out and fiddled with the Control Sheave again. The Control Sheave slides freely on the idler shaft, but as mentioned before, the Control Sheave is binding against the Idler Sheave as can be seen in the photo.

http://www.shopsmith.net/forums/attachment.htm?attachmentid=11220&stc=1&d=1292686644

It takes a little effort to get the sheaves apart after they have made contact with each other. Ordering a new Control Sheave does not mean that this would not happen with a new one. Someone has provided an option of sending them the sheaves and they would provide a good match. Another option with some cost would be ordering a new idler shaft assembly (including a new control sheave). Just checking to see if there are anything that I could do yet to get around this before proceeding with one of the options mentioned above.

Reading between the lines I conclude that you can, with some effort, get the two sheaves apart and that you can get the control sheave off the shaft.

I also conclude that so long as the vanes do not mesh, the control sheave can be moved back and worth on the shaft with almost no effort. This is as it should be.

An inspection of the long key should indicate NO rough surfaces.

All of this being true, it seems that only the friction between the vanes is causing your problem. Doing a visual inspection of the vanes, do you see any excessive wear marks.

If you have visual wearing, have you tried cleaning and polishing the vanes where the wear marks are.

The vanes on mine do not contact one another until the control sheave is almost all the way on the shaft.

[ATTACH]11221[/ATTACH]

[ATTACH]11222[/ATTACH]

How much rotational movement of the control sheave do you get? There should be very, very little because of the keeper (long key).

[JPG]

. . .
How much rotational movement of the control sheave do you get? There should be very, very little because of the keeper (long key).

That bears repeating!!!

There should be no variation of the width of the keyway slot in the control sheave bore(or the width of the key). This can be determined by attempting to rotate the sheave halves retative to each other at different positions of the control sheave along its shaft.

I would alter what Dusty said above to read NO (perceptible)movement.

The purpose of the key/keyway is to maintain alignment of the vanes of the two pulley sheave so as to prevent this 'problem'.

I never had the 'sticking' problem, but I did wear the keyway in the control sheave soo much that it finally started to 'skip to the next vane' at high speed. Now that really caused 'jamming' when returning to slower speeds. Kinda noisey too!:rolleyes:

The control sheave keyway was almost twice as wide on the flange end!

As a temporary 'fix' try judicious filing down the vanes where they are sticking.

If you do decide to replace the control sheave, also replace the key. Also take the idler sheave off the shaft and make sure it is not contributing to this 'issue'. You will need to remove it to replace the key anyway. There is a teeny tiny spring clip down in the center of the idler sheave that prevents it sliding along the shaft(and thus removal as well!).

Since the difficult part has been done(removal from the headstock) all the above is relative easy.

[billmayo]

As I noted in Post #13, I often find the sticking of the Control and Idler Sheaves can occur when either one is replaced. The same is true for the motor Fan and Floating Sheaves. This can be a result of the keyway machining done at different times. The machining of the shaft OD and sheave ID can cause sticking or loose problems. This is why I find matched sets as the only way to replace any of the sheaves.

I have matched sets of the sheaves available. Also I can accept your existing set of sheaves and replace one of the sheaves so they are a matched set. I have dozens of each sheave available. I recondition the sheave belt surface to remove any nicks and scratches as shown in Post #13. I accept trade-ins too. Contact me if interestd. Thanks