Control Sheave Bearing

timberframer · Post by **timberframer** » Tue Nov 19, 2013 9:48 am

Hi Guys!

I'm about 48 hours into Shopsmith ownership, and I've already got a problem. To complicate matters, I've got a rocking chair that has to be finished by Thanksgiving. So the clock is working against me.

I picked up a used Mark V 510 last Saturday. I inspected it as well as a newbie can before purchase, including powering up the machine and running the speed control up and down. Seemed fine, so I bought it. On Sunday, I started turning legs and spindles for the chair.

Let me stop there and make two confessions. 1) I didn't oil the sheaves. 2) I had some trouble seating the drive spindle into the blank. I ended up tapping the free end of the blank with a hammer. I didn't wail on it, but I hit it about as hard as I could using all wrist.

I was finishing my fifth turning when I noticed some squeaking coming from the headstock. I took the belt guard off and look around, but didn't notice anything wrong. Put the belt guard back on and started the sixth piece. I heard a very loud squeak and immediately powered the machine off.

I took the blank off of the lathe and rotated the quill by hand. It turned, but it seemed hard to turn (new to the machine, so wasn't sure how easy it should turn). It was late Sunday, and I was pushing to get work down (witness the recklessness confessed above), so I walked away to gather my thoughts before compounding my mistakes. I researched here to find out what i could, then went out to the shop again.

At present, here's what I know. The machine runs relatively smoothly under no load. I may or may not hear a faint squeak. However, my speed control no longer works. When I try to move the Control Sheave, the bearing that connects the quandrant arm to the control sheave moves/slides inside the sheave.

Question 1) Is that bearing pressed into the sheave, or is there a retaining ring or something that holds it there? I see a roll pin inthe exploaded diagram, but can see how that could hold a bearing in place.

Question 2) The squeak hints at a bearing failure. I know you can't know this, but it's the question I have to ask..... do I risk severe damage if I run the machine until a bearing seizes?

Question 3) Could I have done any damage when I drove those blanks onto the drive center?

Sorry for the long-winded message right out of the gate. I'm under the gun here and need to get this chair done.

Thanks for your time!!!

Jon

beeg · Post by **beeg** » Tue Nov 19, 2013 11:32 am

Welcome to the forum Timberframer. FIRST THING to do is OIL both sheaves. Next time drive the drive spur into the work OFF the spindle, that way ya won't harm the quill bearings.

timberframer · Post by **timberframer** » Tue Nov 19, 2013 12:19 pm

Thanks Beeg.

No arguing with either of those suggestions. I'm embarassed that I missed/ignored the obvious wisdom in those steps.

But, I still have the same problems.

The bearing at the quadrant arm is completely free from the sheave. I need to know if I can secure that bearing in some way, or if I need to order a new Control Sheave.

And I suspect I'll still have that squeal to deal with. I'm not going to have time to replace bearings and get this chair done.

terrydowning · Post by **terrydowning** » Tue Nov 19, 2013 12:31 pm

Was the squeal from the headstock side or the tailstock side? I've experienced squealing from the tailstock side. Live center bearing? or in some case using a dead center and not having enough lubrication on the spindle.

If it's the headstock side squealing, nevermind, continue on with diagnostics as you are.

As for using the drive spur, here is what I do.

Find and mark the center on the drive end, in the usual manner of drawing lines from corner to corner then use a tenon saw and cut kerfs corner to corner where you marked about 1/16" or so deep. Drill a 1/8 diameter hole in the center about 1/8" or so deep. Then tap the drive spur into place with the spindle off of the lathe. This gets the spur set without tapping on the quill shaft and risking damage to the bearing.

joshh · Post by **joshh** » Tue Nov 19, 2013 12:50 pm

To answer your question about the control sheave bearing:

The bearing is pressed into the control sheave. Shopsmith does not service just the bearing and instead replaces the assembly. Aftermarket bearings are available with the rollpin and clip on Feebay. Replacing the bearing has mixed results with folks here. The biggest concern is that it might not stay in place and wants to pull out again.

Bill Mayo said he machines a little extra depth so he can stake the new bearing in place. I don't remember if he said he used loctite also or not.

Here are the instructions for the bearing per Jacob Anderson:
http://jacobs-repairshop.com/my_web_site_023.htm

Where are you located? Someone near you may have something that can get you back in business.

timberframer · Post by **timberframer** » Tue Nov 19, 2013 12:56 pm

Squeal happened fast, so not certain where it came from. I just assumed it came from the headstock.

Great suggestion on the live center. I'll put some light grease on that shaft.

I intend to use this machine for many years. Plus, I'm weary of a bearing failure now. So I'll tear the headstock down and rebuild it when I get a chance. But, for now, I need to get this chair done. In order to do that, I'll have to lube that live center, oil the sheaves, and cross my fingers that I don't do any damage by running it.

As a side note......I'm surprised Lee Valley (or some place that sells all neat gadgets) doesn't sell a punch that prepares the blank to accept the drive center. I was using a center punch to make a hole, a phillips screwdriver (it was late!) to widen the base of the hole, and a chisel to make an "X" for the spurs. It was sorta working, but not well. The "X" wasn't deep enough.

Thanks for your help!

timberframer · Post by **timberframer** » Tue Nov 19, 2013 1:00 pm

joshh wrote:To answer your question about the control sheave bearing:

The bearing is pressed into the control sheave. Shopsmith does not service just the bearing and instead replaces the assembly. Aftermarket bearings are available with the rollpin and clip on Feebay. Replacing the bearing has mixed results with folks here. The biggest concern is that it might not stay in place and wants to pull out again.

Bill Mayo said he machines a little extra depth so he can stake the new bearing in place. I don't remember if he said he used loctite also or not.

Here are the instructions for the bearing per Jacob Anderson:
http://jacobs-repairshop.com/my_web_site_023.htm

Where are you located? Someone near you may have something that can get you back in business.

Thanks Joshh!! That's what I suspected. I'm in the Baltimore/DC area.

JPG · Post by **JPG** » Tue Nov 19, 2013 2:57 pm

timberframer wrote:Thanks Joshh!! That's what I suspected. I'm in the Baltimore/DC area.

Add that to yer profile - it will appear on all posts(past and future).

billmayo · Post by **billmayo** » Tue Nov 19, 2013 3:48 pm

joshh wrote:To answer your question about the control sheave bearing:

The bearing is pressed into the control sheave. Shopsmith does not service just the bearing and instead replaces the assembly. Aftermarket bearings are available with the rollpin and clip on Feebay. Replacing the bearing has mixed results with folks here. The biggest concern is that it might not stay in place and wants to pull out again.

Bill Mayo said he machines a little extra depth so he can stake the new bearing in place. I don't remember if he said he used loctite also or not.

Here are the instructions for the bearing per Jacob Anderson:
http://jacobs-repairshop.com/my_web_site_023.htm

Where are you located? Someone near you may have something that can get you back in business.

Yes, I use a lot of tubes of LocTite 271 (permanent) on almost every thing with threads or has a press fit. Just placing a new bearing in the Control Sheave may not solve your problem for long. I had a couple bearings pull out after a couple of years so I machine .08"-.09" deeper so I room to stake the end of the Control Sheave housing. Not had any failures since doing this. Also just replacing the control sheave may find that it does not fit on the idler shaft, is too loose and/or the vanes hit each other. I always replace the complete Control/Idler Sheave Assembly where I can mix and match the Control Sheave to the shaft and Idler Sheave. I do have the Gilmer and Poly-V assemblies available.

Soapbox Time: The lack of no or insufficent oil in the Control Sheave is the major reason for about 90% of the headstock failures. I find you need at least 12 to 20 drops of oil in the Control Sheave oil hole (Speed Control set to FAST), cycle slowly thruough the speed range and repeat oiling again. This is needed to flush out the aluminum sheave particles and belt dust and other crud that collected at this bearing. I do not believe you can over oil the control sheave bearing as long as the oil is put into the oil hole. In fact, I believe the oil flushed out the control sheave bearing helps lubricated the worm gear and quadrant of the speed control assembly.

charlese · Post by **charlese** » Tue Nov 19, 2013 3:57 pm

billmayo wrote: Soapbox Time: The lack of no or insufficent oil in the Control Sheave is the major reason for about 90% of the headstock failures. I find you need at least 12 to 20 drops of oil in the Control Sheave oil hole (Speed Control set to FAST), cycle slowly thruough the speed range and repeat oiling again. This is needed to flush out the aluminum sheave particles and belt dust and other crud that collected at this bearing. I do not believe you can over oil the control sheave bearing as long as the oil is put into the oil hole. In fact, I believe the oil flushed out the control sheave bearing helps lubricated the worm gear and quadrant of the speed control assembly.

A-MEN!!! If Bill's "soapbox paragraph" is repeated daily in the minds of Shopsmith users (and done every 10 hours of machine time) control sheave problems would be almost completely eliminated.