Control Sheave Bearing

An Ex Parrot · Post by **An Ex Parrot** » Sun Jul 13, 2014 1:47 pm

Just bought a 1989 Mark V, which needs some work. After pulling it apart a bit, the culprit appears to be that the bearing/button assembly was detached from the control sheave and had fallen down below the motor. (Pics attached of the control sheave and the bearing/button.)

From reading many posts on this forum (very helpful!), apparently the bearing is supposed to be attached to the end of the control sheave "tube" (for lack of a better term), so the ring on the bearing can go around the quadrant.

That all makes sense, but I can't figure out for the life of me how to attach the bearing onto--or insert it into--the end of the control sheave tube. See pic #3 attached, which shows the relative size of the bearing vs the tube: The bearing outside diameter (~.75") is significantly larger than the tube's inside diameter (~.612").

Would appreciate any thoughts on how to attach/insert the bearing/button assembly onto/into the control sheave tube!

Thanks,

AEP

algale · Post by **algale** » Sun Jul 13, 2014 2:35 pm

This is a press fit from the factory and it is not supposed to be user repairable. Shopsmith will sell you the entire assembly or you can buy a used assembly. I vaguely recall some users may have managed to reattach the button bearing, but I don't know how one does that.

JPG · Post by **JPG** » Sun Jul 13, 2014 4:38 pm

Methinks it was run with the bearing below the motor, and the snout(my choice of descriptive nomenclature:D) was 'formed' over by the harder steel strip on the quadrant. What was originally a step in the end has become mashed into the counterbore.

I think replacement (new or used) is the best thing at this point. Save it however, it can be used on the motor shaft in a pinch(assuming the vanes mesh properly).

billmayo · Post by **billmayo** » Sun Jul 13, 2014 5:56 pm

JPG40504 wrote:Methinks it was run with the bearing below the motor, and the snout(my choice of descriptive nomenclature:D) was 'formed' over by the harder steel strip on the quadrant. What was originally a step in the end has become mashed into the counterbore.

I think replacement (new or used) is the best thing at this point. Save it however, it can be used on the motor shaft in a pinch(assuming the vanes mesh properly).

I have machined a few motor floating sheaves to install the control sheave bearing. They were all cast and then machined on the same equipment at Shopsmith. I always check the vane spacing between any 2 sheaves as the keyway location does vary enough for the vanes to stick sometimes. I call it a mix and match when dealing with any of the sheaves. So the control sheave without a bearing could be used as a motor floating sheave as long as the opposite vanes do not touch for the motors fitted with the flat washer holding the spring. Early motor floating sheaves had a shorter cylinder so you would have to remove some off the end of the control sheave cylinder.

I have not had much success just installing a new bearing in the control sheave. Even using Loctite often failed over a period of time to hold the bearing. I quickly found if I machine the bearing depth an additional .060" - .070" deeper in the control sheave cylinder, I have room to stake (4 places) the bearing in the control sheave. I have been 100% successful after doing this machining.

An Ex Parrot · Post by **An Ex Parrot** » Mon Jul 14, 2014 10:10 am

billmayo wrote:I quickly found if I machine the bearing depth an additional .060" - .070" deeper in the control sheave cylinder, I have room to stake (4 places) the bearing in the control sheave. I have been 100% successful after doing this machining.

Thanks to all for the quick replies. If I'm understanding correctly, absent the ability to do the type of machining of the control sheave that Bill describes, I won't be able to re-attach the bearing to the sheave. Is that correct?

In which case, I'm curious about these bearing sold on Ebay:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=320637811300&ssPageName=ADME:X:RTQ:US:1123#viTabs_0

These are obviously intended for an owner to do the repair, but how would I attach it if I can't attach the one I already have?

Thanks,

AEP

beatnik · Post by **beatnik** » Mon Jul 14, 2014 11:42 am

http://jacobs-repairshop.com/my_web_site_023.htm

JPG · Post by **JPG** » Mon Jul 14, 2014 12:14 pm

beatnik wrote:http://jacobs-repairshop.com/my_web_site_023.htm

Second sentence, third paragraph matches your 'situation'.

If perusing e-bay for a used control sheave, be aware there are two different versions(Gilmer and Poly-v). They are not interchangeable. Only rely on the pix, since sellers are not known for their accuracy in descriptions.

billmayo · Post by **billmayo** » Mon Jul 14, 2014 1:52 pm

An Ex Parrot wrote:Thanks to all for the quick replies. If I'm understanding correctly, absent the ability to do the type of machining of the control sheave that Bill describes, I won't be able to re-attach the bearing to the sheave. Is that correct?

In which case, I'm curious about these bearing sold on Ebay:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=320637811300&ssPageName=ADME:X:RTQ:US:1123#viTabs_0

These are obviously intended for an owner to do the repair, but how would I attach it if I can't attach the one I already have?

Thanks,

AEP

Yes, Gary does offer this package for the control sheave. I was able to get him to make the button available for my use and has since offered it to other customers. Some control sheaves have the extra bearing depth needed for staking. It appears Shopsmith did not machine the depth as deep as before on the later Control Sheaves. The bearing is 6 mm (.235") wide and I find I need at least .010" or more clearance to stake the bearing.

If you do replace the Control Sheave, I recommend only buying a used set of Control/Idler Sheaves and Shaft combination due to the machining of the key way. I found all new Control Sheaves have fitted OK and can be returned if not. I recommend using Loctite along with staking to hold the new bearing. Check with me if unable to find anything. I offer increased bearing depth with the installation of the bearing and refacing of the sheave vanes as a service for a customer's Control Sheave.

billmayo · Post by **billmayo** » Mon Jul 14, 2014 3:39 pm

billmayo wrote:Yes, Gary does offer this package for the control sheave. I was able to get him to make the button available for my use and has since offered it to other customers. Some control sheaves have the extra bearing depth needed for staking. It appears Shopsmith did not machine the depth as deep as before on the later Control Sheaves. The bearing is 6 mm (.235") wide and I find I need at least .010" or more clearance to stake the bearing.

If you do replace the Control Sheave, I recommend only buying a used set of Control/Idler Sheaves and Shaft combination due to the machining of the key way. I found all new Control Sheaves have fitted OK and can be returned if not. I recommend using Loctite along with staking to hold the new bearing. Check with me if unable to find anything. I offer increased bearing depth with the installation of the bearing and refacing of the sheave vanes as a service for my local customer's Control Sheave.

This is staking on an original Shopsmith Control Sheave. I use a bunt nose chisel to make these 4 indentions to hold the bearing.
[ATTACH]25611[/ATTACH]