I stand corrected and it makes a lot of sense. I apologize for having assumed wrong.
Perhaps the size of the chip and therefore how much it would stay in?
That IJK sounds worth doing but I don't see it in the NIST document I have.Also, I don't know about NIST, but Haas recommends partial peck, that tends to cut drilling time drastically:
https://www.youtube.com/watch?v=AM6nVgK ... 7&index=36
I believe in most cases Haas machines are in a somewhat different class than GRBL machines. That extension could be quite useful for machines that drill thousands of holes all day, every day. How many GRBL users would see a significant increase in productivity for the same sort of extension? Especially when GRBL does not yet support any type of drilling canned cycles?
Actually there is some thought that this is a bad idea. The drill flutes do a pretty good job of evacuating chips if pulled close to the surface, and pulling the drill bit all the way out of the hole allows some of the junk on the surface to fall back into the hole. It then gets recut when the drill goes back to the working front.