Shopsmith Forums

Another newbie question-- It turns out the speed control dial on my recently acquired 1989 Mark V is harder to turn than it should be. I didn't figure this out until I had the chance to try another Shopsmith some days later on which the speed adjusted noticeably more easily. Could somebody advise me if the amount of damage visible on the teeth of my quadrant assembly would explain the difficulty in adjusting the speed? The dial turns easily when the speed control is removed but presumably things are different under load.

Is this damage to the teeth likely to be the only issue or a symptom of a bigger problem?

And, to replace the quadrant (I have a spare) how do I remove the black pin that holds it to the speed controller body?

Thanks for any help. This forum has been great!

-Steve

There is a very good article on what causes that wear on the quadrant and the solutions that was written by the late Bill Mayo.

You can down load it from the post in this link. The file is "Bill Mayo - Mark V Headstock Improvement - Repair Kit for Speed Control and Eccentric Bushing v1.01 13 Jun 2016.pdf"
https://www.shopsmith.com/ss_forum/view ... 90#p185690

The pin that holds it together can be driven out. Just be sure to support the assembly so you don't break it.
One bit of advice. If you replace the quadrant gear, also replace the worm gear at the same time. When one wears, both wear and putting a new gear in with an old gear will most likely make it worse instead of better.

Keep in mind that there was a cause for the excessive wear on the quadrant gears. Generally poor lubrication is the problem. Check the motor and idler pulley sheeves to make sure they are properly lubricated and moving freely.

That wear(all too common) is I believe the result of too fast adjusting the speed towards slow. That is exacerbated by insufficient lubrication of the floating sheave on the motor shaft.

Needless to say, adjusting with the pulleys NOT turning is the worst case scenario.

The floating sheave MUST move outward and keep up with the control sheave moving closed to prevent that stress/wear to the teeth.

Thanks all. I think (hope) my Mark V just suffered from inadequate lubrication and maybe careless speed adjustment. The seller proudly showed me the unfinished original 1989 can of official Shopsmith oil to show me that it didn't take much to lubricate. (If I had it to do again I would have passed over this machine.) But, the motor runs smoothly disconnected from the rest, and the sheaves slide smoothly on their rods / axles, so hopefully with fixing up the speed control and keeping everything properly lubed going forward, all will be well.

Curious if many people use Bill Mayo's roll pin replacement / upgrade described in the article linked in the first reply. Seems reasonable but so far I haven't found the bolt he suggests. Also, I'm a bit confused where he talks about the worm gear needing to be centered on the quadrant assembly, because in Jacob Anderson's video on speed control restoration (https://www.youtube.com/watch?v=w4oaJCKKT3E) he says the worm gear should be offset a little to one side of the quadrant assembly gears. Any thoughts on this discrepancy?

Thanks again. Still collecting parts and tools. Will report back when I make some progress. Looking forward to doing some woodworking instead of metal working with the machine soon :--).

I think you are on your way.

When oiling many of my mentors through the years have offered a number of suggestions. Member JPG has the most relevant one for oiling the button bearing that is in the end of the control sheave half.

His recommendation is that once you oil the sheaves (and that does include the sheaves on the motor shaft) to place the headstock in drill press mode, allow it to run a bit to warm up that button bearing, and shut it down overnight in that position. This apparently allows the warm bearing to accept a portion of the oil (now resting on top of the face of the bearing) as it cools... even though it is a shielded bearing it will pull in some lubricant.

There are a number of folks here in the forums willing to help. I am tied up on some remodeling projects at my home and have not been as active in the last few months. That will change in a few weeks as my new office and studio will be completed.

There I will work to finish my new Shopsmith Book that I began researching last year.

Kindest Regards,

Everett

everettdavis wrote:I think you are on your way.

When oiling many of my mentors through the years have offered a number of suggestions. Member JPG has the most relevant one for oiling the button bearing that is in the end of the control sheave half.

His recommendation is that once you oil the sheaves (and that does include the sheaves on the motor shaft) to place the headstock in drill press mode, allow it to run a bit to warm up that button bearing, and shut it down overnight in that position. This apparently allows the warm bearing to accept a portion of the oil (now resting on top of the face of the bearing) as it cools... even though it is a shielded bearing it will pull in some lubricant.

There are a number of folks here in the forums willing to help. I am tied up on some remodeling projects at my home and have not been as active in the last few months. That will change in a few weeks as my new office and studio will be completed.

There I will work to finish my new Shopsmith Book that I began researching last year.

Kindest Regards,

Everett

JPG cannot accept credit for that process. Again BILL MAYO is de source.

The screw is a 'cap' screw that is not typically found in the common hardware bins. At HD and Lowe's they MAY be found in de drawers. A 10-32 OR a 10-24(3/16") will both work.

I have had to repair the speed control on a Greenie I was restoring and I recommend re-assembling as Bill suggested.

Update: So, I've achieved about a 50% improvement in smoothness / ease of speed adjustment by replacing the quadrant assembly, implementing much of Bill Mayo's advice, and additional generous oiling of the sheave shafts. Replaced the pin in the quadrant assembly with a plain old bolt temporarily while the search continues for one w/ solid shoulder as recommended. Will install that along with a replacement worm gear shaft when it arrives from Shopsmith central. I suspect my worm gear shaft is bent as I noticed a bit of a repetitive variation in force needed to turn the dial before reinstalling in the Shopsmith.

Question--Shopsmith instructions say 'Put a tiny dab of cup grease or "furnace bearing" grease (beeswax) on the worm control shaft and rack of the quadrant assembly'. What is the best thing to use here? Can I go to my local auto parts store and ask for cup grease? I don't have a bee hive but I do have a block of solid beeswax. Lithium grease?

Thanks, Steve