Posted by Dimebag on April 19, 2022 at 16:54:20:
In Reply to: Re: question on cutting 12 degree helix angle posted by jon on April 19, 2022 at 13:41:13:
Your evaluation is correct, it's 5.0771 vs. 5.08 NDP. It seems close, but it will also produce something like 0.0016" tooth thickness error over the tooth's whole depth. It will also cause a slight helical error over the face width in order of 0.0005" over 4" face width. The helical error could be compensated for, but the profile error is a much greater problem. It could maybe work for a coarse gear, but I recommend getting a proper 5MOD hob to get the work done well. There are tool rental programs available that might be interesting.