T20 Input Shaft - what steel is it made of?

[Rusty-Gunn]

Rather unusual question, but what steel is the T20 input shaft made of?
I intend to buy another used shaft, cut the clutch-end off and have it welded to the shaft in our T20 to extend it's length by a few inches or so.
This isso the clutch won't wobble to death when it comes loose. (Yeah, I use threadlock and new lock washers, but it eventually rattles loose, and wobbles. This happens at the worst possible times, murphy's law.) I don't need a short shaft for easy removal of the clutch, so an extended shaft will work for me.
I think it would help my welder know what the steel is, so he can weld it properly. Thanks.

[onlyonce]

I think you should try and figure out what issue is causing the clutch to want to wobble loose. That doesn't seem to be a very common problem with these machines.. May double check the drive and driven alignment. Don't believe welding to that hardened shaft will work out. Needless to say runout would be awlful.

[Noel Woods]

I think the problem may be elsewhere. Most of the t20 shafts I have seen have all been secured via a 3/8" x 24 fine thread bolt 3.5-4" long and a keyway. I know of several folks that had the clutch wobble issue or even had the clutch fly off when running. In those situations the issue I saw was that either the key wasn't in the keyway or that the bolt was a course thread instead of the fine. Either way the clutch was not secured to the shaft. I would also use some locktite to make sure it stays in place.
I believe the shaft material is not high strength steel so it should weld if you have to go that route. That will have to be a precision weld and it might be tough to do as it will have to be balanced. I know that forum member Whipper has a machine shop in Arizona named "Apache Gear." If you need a longer shaft he would be the person to talk with.
Hope this helps.

[ARGOJIM]

I would check the driven bore.

[tbone9]

You can also check your slider buttons. If one breaks off as they tend to do it will wobble pretty bad. I’ve run into this a lot because the buttons weren’t held in with locktite retaining grade.

[Rusty-Gunn]

Thanks for the responces, much appreciated.
The secondary is/was new last summer, and mounted with the prroper bolt, with locktite, and a new lock washer.
Several times over the summer the bolt unscrewed itself. When the bold loosens, the clutch is free to slide left and right.
When it slides too far to the left the key can slip out. At this point the clutch wobbles due to it being mostly off the shaft (which is short to begin with) with barely any support.
I suppose I didn't use enough locktite.
Which one do you recommend, blue? Red? Another brand?

If the shaft must be balanced after precision welding, then its best not to cut/weld them. I have no way to do this.
Having a custom length made might be costly, so this path is a no-go.
I think I'll skip this idea and not weld an extension.

What is the recommended torque this bolt should be tightened to? (I now have a torque wrench.)
Locktite, which one?
Thanks fot the help guys.

[onlyonce]

I use blue and have never had a problem. My guess is somewhere in the neighborhood of around 40ftlbs, but you may want to look into that further.

[Rusty-Gunn]

Thsnk you.

[jerseybigfoot]

The washer on the bolt may be collapsing and the bolt start to loosen. to increase the rigidity of the assembly I've used a piece of 7/8" od heavy wall tubing as a spacer between the T20 shaft end and bolt washer. Make to the spacer slightly short of the clutch to get some compression on the bolt washer.

[msafi65]

I make a clutch washer on the lathe that is about 3/8 thick with 7/8 shoulder to center. If the shaft has had the clutch loose and is worn down below .874” at the extreme outer end the clutch won’t stay on. I’ve set several that owners didn’t want to replace the input shaft with gap filling lock tite and have had a couple run for several years. I don’t recommend it. A new shaft and clutch have about .001” clearance.