Making a 2 inch diameter, 2 TPI press screw:

I decided to create a separate page devoted to the new 2 inch screw for my cider press. Mostly pictures…
The screw I’m replacing…1.5 inch, 6 TPI:

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A sketch of the screw I want to make:

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First to make the tap. This will be used to cut threads in the big 2 inch nut. See Roy Underhill’s “The Woodwright’s Notebook” and Fine Woodworking’s “Techniques 1”.

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Then the guide for the tap:

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Now to tap the nut in 2 inch thick locust:

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Cider Press Screw (blah, blah, blah)
October 11, 2013
Bart Gardening, Smithin’, Woodworking Leave a comment

I know you guys are probably getting really BORED with my rants about the replacement screw for our cider press…too bad…this is my blog! (Ha-ha Hee-hee in my best egomaniacal laugh…) Anyway, thanks for stopping by. I have never done this before and thought it might interest my fellow nerds…
A couple days ago I turned a pretty fair cylinder from a chunk of beech a friend gave me. I say “pretty fair” because an expert turner I’m not. Most of my turning experience has been making tool handles and such. This morning I laid out the helix for the 2 TPI threads using 1/2 inch electrical tape. The tape was spaced just far enough apart for a saw kerf. And saw I did! Pretty tough going with the little backsaw in seasoned beech. The 1/4 inch depth for the kerf was marked out with tape as well.

Then, after unwrapping the tape, the real fun began! Chopping and paring the threads with chisels is slow going. I penciled in the center of the threads by eye then pared almost to the line. I only have 4 threads so far with 24 more to go! When I tried them in the nut I made last week the fit was good…a little tight, but good. I’d rather have it a little tight initially so I can trim to a better fit. By the way, the unthreaded portion in the left of the picture is waste that will be trimmed off later.

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2 Comments (+add yours?)

  1. Kelly
    Jan 20, 2014 @ 13:23:03

    Have you made the die to match this?

    Reply

    • Bart
      Jan 20, 2014 @ 14:17:46

      No die. The threads are laid out directly on a blank turned to the major diameter. A kerf is sawn to the root diameter. Then the threads are hand-carved with chisels and rasps. I’ve added some pictures to my screw page to help illustrate.

      Reply

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