Posted by BillS on March 07, 2008 at 13:09:28:
In Reply to: Re: Hobing Helical Gears on a Wolf GH32-11 posted by MSB on March 02, 2008 at 05:59:20:
There is a good section under "speeds and Feeds" in the "Machinery's Handbook" from Industrial Press. I have the older 21st edition, but it is widely available in later editions if you don't already have one.
It has formulas for converting spindle RPM to Feet/Minute, and a lot of good information about tooling and work materials. There is so much involved with "optimizing" production versus tool life that you usually start with a basic speed and feed based on material and tooling and then make changes from there. That's why I suggest the Machinery Handbook as a good place to get familiar with the trade-offs.
I've found that there is usually a feed rate that optimizes tool life between sharpenings. Too slow or too fast is worse, but usually fast feed is limited by finish and machine power rather than tool life. Too slow exposes the cutter to excessive friction and bad chip formation. But that's just a rule of thumb I used to use.
For those using CPC-HOB, there is a very simple table to suggest a basic starting point.
If anyone is interested, maybe I can put up something in the FAQ to add more detail regarding speeds and feeds. But I would really like to see a conversation on feeds and speeds before tackling such a project.
Post a Followup