bronzes?

Maybe then Delrin but the UHMW is probably too soft and will deform under load. Gut feel says that free machining ( leaded ) bronze would be the way to go.

Tom Miller

occurred

jim rozen wrote: I put new adjustable nuts in my

Tell me more. Did you single point the threads?

Kevin Gallimore

Yep, it really wasn't that hard. The nuts on that machine are two-piece adjustable, there's a smaller diameter, long part that threads deep into the table, and is held solid with either a pin or a setscrew (forget which). Then the outer part of the hole in the table is threaded with a fine-pitch thread, for a shorter section of nut, which threads in until the acme threads in both sections line up and you can pass the leadscrew.

At this point the lash in the combination is set by turning the outer part in the fine thread. It gets locked in place by a lockring that jams against the outer surface of the table.

So the entire job consisted of making two of the inner, smaller nuts, and two of the larger, outer nuts. Both of course had to be ID threaded for the acme thread, and the inner ones had to have their OD turned to be a nice snug fit in the bore. The outer ones had to be OD threaded to fit the existing fine threads in the table.

I made them out of a chunk of bronze from mcmaster car. The old nuts were pretty thin, there was almost no meat left on them. The machine itself is so old there's a lot of wear on the screws themselves, so I can't adjust the nuts down real tight. Given the overall wear level in the machine, it works pretty well.

Jim

Let me just correct the record in this thread: both nut and screw are available from Clausing service center. I'm just off the phone with them. My mistake.

Adam