OldTools Archive

Recent Bios FAQ

274662 Erik Levin 2021‑10‑08 Re: Do you trammel?
I will admit that one set I have is the Starrett purchased at fire sale pricing,
with the selection of ball radii. But the set I most use, I made, as having
matching size ball ends is very handy using soft(ish) 1" steel balls from
McMaster (the weldable grade). Carefully bore a hole into it- a lathe is nice,
but the first set I did on a job 20 some-odd years ago was with a drill press
and careful setup- and set a rod in. Braze is good, epoxy works too.

If not perfectly enough centered (1/64 is good enough for a lot of work, most of
mine are 0.005" or better), mark the fat side, hold the shaft in a vise a little
back from the ball, and tap with a hammer to bend the shaft. It is surprisingly
easy to got good enough. The first set wasn't well enough lined, and I didn't
think to adjust them at the time, so I marked for orientation to make it easy to
set to the middle rotation that matches the sharp points. This gives fine adjust
for the ball if I need it, like when striking concentric around a hole.

Non-concentric points can be similarly marked to make it easy to find close
enough to the neutral position while allowing you to twist for fine adjust.

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On Friday, October 8, 2021, 05:31:10 PM EDT, Bill Ghio  wrote: 

Oh my, I want one… and only $5.75.

Recent Bios FAQ