Re: [CAD_CAM_EDM_DRO] screwless focuser was Re: re:Re: Re: Is this too nuts to consider ?

Yes, you file the thread!

And you can do it fairly accurately too.

The easy way to go about this is to first make a flat template of the thread
on a piece of paper or perhaps a thin sheet of aluminum such as an old
printing plate. To do this you layout a right triangle with the short side
equal to the desired pitch (one inch in this case) and the second side equal
to the circuference of the tube. Draw the hypotenuse and then draw a line
parallel to this that will intersect the short side of the triangle at a
distance equal to the pitch. Cut this section out (you should have a
parallelogram with one side equal to the pitch length). You can make this
parallelogram as long as necessary.

Tape this to the tube with the pitch lead side (the one inch long leg)
parallel to the tubes axis. Wrap it around the tube keeping the long sides
together and tape the opposite end. When you get done, it will look like a
long fast twist spiral tube...like those used in toilet paper rolls. The
joint along the paper is the actual lead.

Now you can mark the tube along this joint, remove the paper and use the
mark for a guide for filing. With care, a pretty good thread can be
obtained this way by hand.

Smoke

>Perhaps file a shallow thread? I would think that would work.
>
>Les
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