I recently bought a dividing head and in an effort to understand
how to use it I went through an example to make a gear.
Machine shop practice covers it pretty well.
I picked a 96 tooth gear because a project I have in mind uses one.
40/96 = 5/12
Which means I need to rotate the handle 5/12 of a turn for each
tooth. Looking at the index plates (A,B,C) I have choices of 15-20
on plate A, 21-49 on plates B and C. There are no plates with
a multiple of 12. I am also puzzled why there are no even numbers
above 20. Plates B and C have only odd numbers. Why?
It seems to me that I need to make an index plate with 12 holes
in order to make this gear. Am I missing something???
18 years ago