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Basically what I started with (not the actual eBay image).
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US Pat No. 859,059 - all together.
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Here's what I was missing.
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The final result.
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The first step was to reproduce the thumb nut that holds the removable
piece down by the chuck. This wasn't easy, because I did not want
to remove the existing thumb nut from its place. I had to guess
at some of the dimensions, such as the pitch of the threads and the
best "tap drill" diameter. Then, that's a blind tapped hole in
the thumb nut. At least, the threads are right-handed. You
will note that I had to modify my estimates as I went along ... and make a plug gauge to check the progress of my threading.
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I do not have any means of knurling, so I used the lathe as a shaper
and chased the grooves one at a time, using the lathe's bull gear as a
divider.
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My
"new" removable piece was donated by an old, decrepit Stanley Rule
& Level corner brace, where the end was smaller than it should be,
and threaded 7/16-22 to boot.
Therefore, I had to make an adapter to fit the smooth interior of the
socket into which the removable piece had to fit, and it had to have a
key to prevent rotation of the universal-joint housing. The
adapter's internal thread is almost as large as its external diameter,
and it had to be a tight fit on the end of the removable piece.
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The original patent's latch was flimsy ...
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I had to design my own arrangement.
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Here the latch is in the locked position.
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There's a spring & ball to hold the latch.
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There are several sleeves and
packing pieces to take up the slack in the very sloppy fits of the
original brace's various pieces. They're bronze, salvaged from old
tensile specimens.
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US Patent 859,059, July 20, 1906
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The pieces go togther now quite nicely, and the brace is fully
operational in either configuration - as a straight brace or as a
corner brace. If there's one nagging flaw,
it's that the split screw over which one or the other of the two thumb
nuts fits is insecurely attached to the universal joint housing and
falls off relentlessly during any changeover. The patinas of the
two portions match pretty well, except for the freshly made pieces, of
course, and the wood handles are good matches for each other.
Maybe the original removable piece was also made by Stanley ...
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