Speed Changer nut falls off

[bsherman]

Just purchased a used 500. This is my first experience with a ShopSmith. The speed changer was hard to turn and a little clickey. I took it apart and cleaned it. When I reassembled I found that the Hex Jam Nut (124818) kept falling off and was rolling around jamming things. After several tries I just left the nut off and it still works. Unfortunately some of the teeth on the Speed Control Handle are broken off. (Maybe because of the nut rolling around.)

[*]Teeth missing on speed control is going to cause slipping and the speed dial will not stay accurate right?
[*]I never saw anything resembling the Idler Bushing (504219). Maybe it was missing. Is that what keeps the hex nut on?
[*]Is the hex nut just supposed to be a "normal" nut. (Looks like any other nut from the hardware store.)

Thanks!
Brian

[algale]

You may want to watch this video which shows how to replace a speed control, it may give a few insights.

[youtube]https://www.youtube.com/watch?v=u4MW_c350sA[/youtube]

[bsherman]

You may want to watch this video which shows how to replace a speed control, it may give a few insights.

[youtube]https://www.youtube.com/watch?v=u4MW_c350sA[/youtube]

Thanks for the link. It's funny, his is loose too. (At 9:43 he says "I'm going to take off the jam nut which for some reason is loose")

I think what I'm missing is the idler bushing which keeps the jam nut from tightening against the gear. When I tighten my jam nut, the action of adjusting the speed unscrews it and it falls off inside the control.

Sound right?

[algale]

I assume if that bushing is missing, the gear will have a sloppy fit on the post/screw and that can't be good for anything, including keeping the nut on tight.

Incidentally,there's a guy on ebay who fixes the busted teeth on the back of speed control handle. You ship him yours, he sends a replacement that has a pressed in steel insert with machined steel teeth.

If you are new to Shopsmith you should check out the maintenance videos on the Shopsmith.com site under the Woodworking tab called "Sawdust Sesstions." The video I linked you to is just one of many.

I'd be concerned that the reason your speed control got out of whack to begin with is that it was not adequately maintained and lubricated. I'd want to take the headstock apart completely and lubricate and adjust everything. If you watch the Sawdust Session videos, it will be a snap.

And if I didn't say it before, welcome to the Forum.

[JPG]

[quote="bsherman"]Just purchased a used 500. This is my first experience with a ShopSmith. The speed changer was hard to turn and a little clickey. I took it apart and cleaned it. When I reassembled I found that the Hex Jam Nut (124818) kept falling off and was rolling around jamming things. After several tries I just left the nut off and it still works. Unfortunately some of the teeth on the Speed Control Handle are broken off. (Maybe because of the nut rolling around.)

[*]Teeth missing on speed control is going to cause slipping and the speed dial will not stay accurate right?
[*]I never saw anything resembling the Idler Bushing (504219). Maybe it was missing. Is that what keeps the hex nut on?
[*]Is the hex nut just supposed to be a "normal" nut. (Looks like any other nut from the hardware store.)

Thanks!
Brian

The nut is a jam nut(2/3 size of standard nut).

The bushing must be there to both provide the proper diameter for the gear to pivot on, and provide something for the nut to tighten against. It's length is such that the nut does not press against the gear so it can rotate freely, but the nut secures the gear.

You need the bushing. The od is 3/8", the id is 1/4", the length is about 7/64(0.106")

[bsherman]

That explains it then. Somebody must have gotten in there and lost the bushing and nut. Then just replaced it with a regular nut.