Posted by BillS on May 30, 2009 at 15:50:17:
In Reply to: 3 start worm gear posted by David Hollinger on May 27, 2009 at 15:09:45:
Using 7NDP, worm OD, and 3 starts, I get the helix angle of the worm (and the gear) this way:
starts
Helix angle = Inverse Tangent (--------------------------)
(OD-2/NDP)x NDP
Helix angle = 16.157 Deg
The worm Lead angle is 90 - 16.157 = 73.84 Deg