Posted by BillS on May 01, 2006 at 12:46:07:
In Reply to: How to hob an enlarged pinion? posted by Kevin on April 28, 2006 at 14:45:02:
Ron is absolutely correct in his response - thanks Ron.
If you are using a non-differential hobber, the index and feed change gear sets must be determined for standard specifications of teeth, pitch diameter, and helix angle. In other words, a standard helical pinion setup is not affected by "holding out" the cutter for an enlarged OD.
I mention teeth because there was a common approach to enlarging an OD by "adding one tooth" when calculating an OD. I'm not sure how this got started, but you don't actually add a tooth except in the calculation of OD. Today, There are more modern calculation methods to determine an optimum amount to enlarge the OD.
I think there are mentions of enlarging pinion OD further down in the forum. If someone would like to elaborate on practical design methods of enlarging pinions, please do!