John L. Weatherly wrote:
My father-in-law has well broken in drill press that he wants me to repair.
He told me it was built in 1918. It says "CANEDY OTTO MFG CO" on the side
of the column. Flat belt driven. Has a counterweight inside the column
with a chain attached to the quill. Has all kinds of open gearing on it.
Has been retro-fitted for an electric motor.

The problem is the gear that engages the rack gear on the quill is stripped.
That means no feedy up or down. The shaft the gear is machined on is in
good shape. It looks looks like they machined the entire shaft and
shouldered up to the gear. Weird.

Two questions:

1) Should I build up the gear with weld and machine it down, or machine the
gear separately & silver solder it on? I have lathe capabilities as well
as a 25" Smith & Mills shaper with a dividing head on the way (generous
payment [gift] for the job.

2) How the hell do I reverse engineer the worn gear? I can count the teeth,
but that's about it. The rack gear on the quill is in decent shape. I'm
sure there is an equation three pages long for it, I'm just ignorant about
gears.

What do y'all think?

--
John L. Weatherly

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Dress a cutter tool to the root shape of a pair of teeth on an unworn
area on the rack. Now count the teeth on the gear and measure the
diameter. Layout a circle to that diameter and layout the teeth to match
the old gear.

As for how to attach it. I would machine the current gear down the a hub
in a standard size. Machine the new gear in that size minus a few
thousandths. Attach the new gear by heating it in an oven and pressing
it on the hub. Once it cools it will be solid, no key or solder involved.

--
Steve W.
Near Cooperstown, New York