Headstock repair

[JPG]

To folks living in tornado alley you can believe tis definitely NOT a 'figure of speech', but a very real potential personal disaster!;)

[alisfair]

I am in Grand Rapids, Michigan and would like to find other owners of shopsmith equipment. I would appreciate anyone for the info. New to the forum and happy I found it.
Good woodworking,
Alisfair

[randythewoodchuck]

OK, folks, I followed your advice and have attacked the problem I am having with my speed changer all by my lonely, except I have you all to help. As I am unsure exactly where my problem came from, I will take this a step at a time.
(BTW, the links you all suggested, along with links that were found from those links has helped my confidence level greatly. Thank you all.)

Problem #1: The speed control handle set screw (3/32 allen screw) has wanted to back out and allow the speed control handle to slip on the post it is supposed to turn. Not sure why this is. (Is this a common problem?) Having removed the speed changer I am wondering if the seat for the set screw is corrupted. Picture below shows this. Can anyone comment on whether the seating might be the reason the set screw won't stay put? If not, how do I solve this problem?

[ATTACH]23025[/ATTACH]

[JPG]

Not sure about 'corruption', but double dimple for sure. It appears the outer 'dimple' is deeper than the inner one.

Is it possible you are tightening the set screw into the 'inner/shallower' dimple and the knob/screw are migrating to the deeper one?

What does the end of the set screw look like? Cup point I hope!;)

I would attempt to seat the set screw into the deeper dimple. Make sure the set screw is bottomed out in that dimple.

Yes they have a habit of coming loose if not tightened securely in the dimple.

[randythewoodchuck]

I have the assembly removed. When I pulled the speed control assembly I found that is was gunked up, so cleaned it as thoroughly as I could.
I've a couple of questions at this point.

1. Does the speed control assembly require any lubrication. Seems to me that even a light oil would only attract sawdust and other particulates that would regunk the mechanism.

2. As I wrote in my previous post, w/picture, the set screw will not stay tight. I am as sure as I can be that I have been tightening it into the deepest area of the dimple. I am contemplating three different solutions for this, and would celebrate any comment:
-Purchasing a new speed control assembly
-Replacing the control shaft only
-Using Loctite blue on the set screw.

The only issue with the speed control assembly that I can see is that the speed control dial won't stay put, as mentioned previously.

I'm leery of only replacing the control shaft, as my experience with replacing part of a whole on something old has not been good. I believe that the control assembly is the original. My Mark V was built in 1979. However, there is a significant price difference between a complete speed control assembly and a control shaft.

I appreciate all input. It has been helpful.

[joshh]

Use dry graphite for lube on the speed control


I had good luck just replacing the worm gear and the quadrant (aka porkchop on the rear). The teeth were chewed up and the gear was bent from lack of maintenance when I acquired it. If all the rest looks good, you can probably just do the worm gear and be ok.

I think I'd try blue loctite for now. If this gets it working well, I'd order a new worm gear and replace it next time I dug into the speed control...but I'm a cheap ass




Before doing that I would inspect the quadrant on the rear and make sure it's ok while you are at it. it's a common fail item. The teeth should look like the one on the right below. If it looks like the one on the left, you might consider doing more than just the worm gear.