What material for acme nut

[Cadillac]

A friend of mine purchased a 5x7 Kalamazoo well saw from the auction for a steal. Bad part is it was missing the moveable jaw and only the acme nut for the jaw screw is there. I’ve already made the vise jaw and now I need to make the nut. What bronze would be the most durable. The nut is different in the way that once pressure is released on the vise it can be rapidly moved. I have the same saw so duplicating the nuts specs should be easy but I’m alittle confused on which material to use. The nut only has threads on half the hole and the hole is elongated with a spring to be able to disengage from the screw for rapid movement. Any advice on what bronze to use. I’ll try and post a picture of the nut arrangement later.

 

[C-Bag]

Maybe you bail on the whole bronze thing and go Delrin like Ulma Doc did on his crosslides. He seemed pretty impressed last I saw.

I'd love to see details of that acme nut and how it works.

 

[Ulma Doctor]

Aluminum bronze is nearly indestructible and would make a great nut that may outlive all of us.
It would be a cool experiment to make a delrin nut but the threads may deform a bit under extreme compression where the aluminum bronze won’t deform in the same manner

cool project!

 

[rgray]

I'll second the aluminum bronze idea. Probably C95500 Some info: https://www.dura-barms.com/bronze/nickel-aluminum-bronze/c95500.cfm

I was running just whatever bronze I could find a good price on on my cnc lathe. Once I had a big box of curls I decided to melt
some down and cast it into a cast iron muffin pan.
The resulting "muffin" of bronze was really tough. And interesting to machine.
Some of my chips were from C95500 and a few other aluminum bronze mixes.

 

[Cadillac]

I wouldn’t think delrin would be a good candidate in this application. The vise sees heavy forces to secure the material being cut. My original bronze nut is in okay shape which I will make two one for me to replace mine and one for the friends missing one. Im ok with making out of bronze just looking at McMaster they have 4or5 different bronzes with different characteristic so I wanna get the best one for the application. When I get home I’ll post some pics.

 

[benmychree]

Specification 954 bronze would be a good choice; McMaster Carr sells it. It is tough, but not so tough that it is difficult to machine. 660 bronze is too soft for the application.

 

[Cadillac]

Thanks for all the suggestions guys. I called Kalamazoo to see if part was available and I couldn’t believe the price for the whole carrier Assy. For just the nut they wanted 45.00 and for the whole carrier Assy they wanted 55.00. I couldn’t believe it because I can’t even get the bronze material for that cheap so that’s gimme. Ordered today they said 2days. Here’s some pics of the old one and carrier so you can see the design.

 

[middle.road]

Now there's a success after all the usual 'arm and a leg' that it usual turns out to be.

 

[Cadillac]

Well package came yesterday and we got a winner. I was happy it was what I was expecting. The cast iron carrier and bronze nut with all the little parts ready for assembly. Can’t beleive all the parts were cheaper than the raw material for the nut. Kalamazoo/clausing in Michigan great American company.