Re: [atlas_craftsman] half nut
- You have just described the half nuts on the Craftsman "109" lathe, made by
"AA products" back in the 1940's (and later).
I had a Craftsman badged 109.20630, and that is precisely how they worked.
Ther was a space of 3 or 4 inches between the two halves, and the lever
rotated them into and out of mesh with the screw.
----- Original Message -----
From: "Bruce Freeman" <freemab222@...>
Sent: Wednesday, June 30, 2010 3:47 PM
Subject: Re: [atlas_craftsman] half nut
Sorry to hijack this subject, but I just noticed the really clever
"half nut" in Gingery's plans for a metal lathe. For those of you who
don't have these plans, envision a coupling nut with a shaft welded on
at the center of one face, perpendicular to the threaded bore. Now
chop away the center to at least the OD of the threads . Next cut
down the axis of the threads from each end, in a plane parallel to the
shaft. Cut away the upper portion of the threads on one side of the
shaft, and the lower side on the other. Hence, what you have is a
half nut on each side of a rotational shaft, but the two half nuts are
not opposite each other. Rotate this assembly one way and it engages
the lead screw. Rotate it the other and it disengages. Simple and
neat. I don't know how well it works in practice.