Hobbing Worm Wheel - Need Help

[olderdan]

Need to know diameter of worm wheel for the following numbers of teeth: 30, 32, 36, 40
for worm dia 24 mm x metric trapezoidal thread TR3

Even have plenty round bars of phosphorus bronze in various diameters wouldn't like
to use hit and miss approach.

Many thanks in advance / Best regards
LMMasterMariner

Found this in Engineers Handbook which may help.

Not sure of your method of cutting these but if free hobbing you need to gash the teeth first.
I think I would try a test on plastic or alloy to prove, good luck.