The very current issue of Model Engineer's Workshop, the British mag, has an
article on gear hobbing which uses electronic synchronization.

GWE

Karl Townsend wrote:

...

- After determining the ideal ratio needed to fabricate a helical gear,
how do you determine the best combination of (A/B)*(C/D) in your
gearbox that closely approximates the ratio?

- how often do you need to change your gear setup?

- how long does it usually take for you to find the right values for A,
B, C, and D? (half an hour? an hour?)


This can indeed be a difficult problem for odd sizes. Here's a web site that
has a great discussion group on hobbing, and offers computer software to
solve the gear train setup:

http://www.meshingwithgears.com/index.html


FWIW, hobbing for the hobbyist pun has been a great interest of mine.
Electronic gearing is the solution for this problem. You slave the index
drive to the spindle. Everything can then be done on a knee mill and
indexing head. A fellow named Jon Stevenson has one up and running. Another
fellow, named Don Foreman, has designed and built a better brainbox. Just
for me. He'd be glad to share with anyone. I was all set to have it running
last winter until more urgent matters intervened.

Karl