# How do I attach an Acme shaft to a handwheel?



## RichSimon (Aug 29, 2014)

Bought a great heavy handwheel on eBay, 8" diameter, planning to attach it to a 1" (2 start) Acme shaft for a leg vise. So far so good.

The wheel has only a hex hole in the center, fairly smooth, measuring 38mm across its flat edges. Been walking through some ideas, looking at McMaster Carr, etc., but really not sure what the right way is.

Considered a set screw through the wheel and the rod, but it looks like the angle might be tricky to drill into the wheel (and it's hard as heck). Thought about getting a 38mm hex nut, maybe with a flange, but then I'd need to get the Acme screw into it. Also, I don't weld, or at least haven't found a reason to (yet).

Mechanics, machinists - ideas?

Rich


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## distrbd (Sep 14, 2011)

pins and bushing comes to mind,
http://www.elkhartbrass.com/files/aa/downloads/manuals/98454000%20GWP-6%203%20Installation%20Instructions%20Rev%20A.pdf

http://lumberjocks.com/topics/54189


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## Dal300 (Aug 4, 2011)

38mm is a tight 1.5". Buy a 1 7/16" nut, insert and epoxy in. Epoxy the center of the nut, drill out and tap the center of the epoxy, thread into hole with a 1" nut and washer on each side.


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## RichSimon (Aug 29, 2014)

I like the epoxy idea. Looking quickly though it seems the acme taps are more expensive than the acme rods!


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## August (Apr 27, 2014)

The only other way is buy a brass hex on eBay and just file it to fit your hex,.
The. Drill the brass to fit the acme shaft.
Coming from a wannabe machinist there is really no easy way to do it with out a lathe and a mill.
Or one more 
Idea is have some one weld the acme over size and file it to fit the hex.
But getting it to line up straight is not that easy.
I made something like what your trying to do.
I have it posted on youtube


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## Dal300 (Aug 4, 2011)

I have a couple of friends who are master class machinists and fabricators. One even does old style forging to make parts for 'Pop and Stop' engines.

I have watched him make beautiful forgings of rods and bearing caps that cannot be distinguished from the original by eye.

I'm still wondering why you would actually need an 8" hand wheel, as a 4" would work nicely. 
You could probably sell that one and buy a couple of smaller ones that were more useable.


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## Dark_Lightning (Nov 20, 2009)

The wheel doesn't have to be centered exactly in order to spin it. Grind the threads off the shaft; it doesn't have to be perfect (though it would be nice to have the handle on the wheel not travel in and out while you turn it, so some care is in order). Then just get a piece of hex bar that fits the inside of the hex and has an ID around the OD of what you just ground off. Make sure that the hex bar is long enough (like 2") that you can put a set screw in it (or just drill through and pin it) to hold beyond where the hex part is inside the hand wheel. Epoxy the hex-to-hex interface. Done.


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## runswithscissors (Nov 8, 2012)

Well, now you've found a reason to learn welding. I taught myself, and I love the way I no longer have to rivet and bolt stuff together. I'm sure a real welder would cringe at some of my "technique," but it works for me. I make jigs and tool modifications that I wouldn't even consider otherwise. I use a wire welder, by the way, and almost always use flux-core wire to simplify the process.

The way I'd approach your task would be to grind down the threads on the acme all-thread (as suggested above), bore out a nut that's 38mm across the flats (or as close as possible), and tack weld it in place. To get the wheel to stay on, bore a hole endways, centering it right at the joint between the hex nut and the wheel. Tap it, and run in an allen screw. The wheel can't pull off because of the threads. To remove, just back out the allen screw. I haven't tried this, but I bet it would work. The same process would work to hold the bored out nut onto the shaft without having to weld.


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## unbob (Mar 10, 2013)

I would bore the hex out, make "on a lathe" and press in a steel bushing that fits the screw, then preferably drill and ream for a taper pin. Or, drill for a spring roll pin-there making the newly bushed handwheel a press fit on the screw also.
Having a bench with a leg vise and an end vise, I would be more inclined to use a 2lead screw on the end vise.
Since the leg vise has a shorter travel between having to set the leg pin, the 2lead screw travels very quickly.


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## longgone (May 5, 2009)

I would take it to a good machine shop, tell them what you want to accomplish and ask what they would suggest.


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