The OEM gears on the lathe were in pretty rough shape after 90+ years of
service. The bores and keyways were OK but the teeth caused a lot
of cyclic rattle.
These are 14.5 degree PA, 12 DP, 30 and 60 tooth spur gears.
had replacements available right out of their catalog. One of their
local distributors was responsive so I ordered the three gears.
They came quickly, the fit & finish were quite good. The catalog gears
shiped with 1/2" diameter bores which I bored out to 1.5" and put in
3/16" keyways- the shaper head came in very handy, doing the job
The replacement gears are steel but the shaper did a nice job of cutting
out the little cheese-slices as seen below. This pics show the
tool bit from the backside where I have a 1/4" HSS blank soldered to the
3/16" cutting tool to stiffen the otherwise quite flexible tool that has
to reach 2" down through the bores. Since there is no clapper box I had
to feed when then tool was clear of the work, which became much easier
once my ear was attuned to the sounds of the machine. About .005" or a
bit less per stroke seemed about right, the head didn't sound as if it
was laboring and the cutter easily took out the material.
With the gears installed, the train is LOTS quieter. The gears
mesh better too, I'm very happy with them.
On this older style machine, the middle gear runs on the 1.5" stud, the
other two are keyed to their respective shafts. The middle and
right-hand gears use the quadrant arm as a thrust bearing, which I'm not
fond of but theres no sign of wear so I guess its not so bad.
The new gears are a tiny bit thicker than the old ones, which causes
friction when the the retaining washers are tightened. The old washers
didn't fit so well themselves, so I made new ones with additional
clearance so the gears run free. I didn't get much of a chance to
make chips over the summer so getting the machines running again is a