On Feb 18, 9:59*pm, wrote:
...It turns out that I
have a 30 tooth gear and a 32 tooth gear and that the ratio between
these gears, times 36 TPI, which my lathe does have, results in a
pitch only .0001 different than .75mm, calculated to 5 places. ...
Eric

Good idea.

My lathe's gearbox chart was missing so I made one up with a
spreadsheet. I changed a copy of it to show the metric modulus for
each pitch and experimented with gear ratio multipliers to get exact
values.

Jim Wilkins