On 2010-09-02, Pete C. wrote:
No dwell is required to break the chips. The chips will break the
instant you stop cutting, i.e. when you reverse the feed to retract. The
bit is still spinning and no new metal is being cut to grow the chips,
so they break off from where the cut ended. Any dwell only add time for
the chips to rub more, generate more friction heat, gall the inside of
the hole and potentially jam. The whole idea of a peck drill cycle is to
get down to where you are cutting fast, make a short cut and get the
heck out of the hole fast to evacuate the chips.

Pete, I thought that a dwell would not be accompanied by withdrawing
of the drill. Just dwell, break chips and keep drilling.

Anyway, it is really fun to watch the mill use a peck and drill
cycle. I will try to up the speed.

I crashed yesterday and went to bed early as I was very tired. Had no
time to try anything. I will take pictures of my manual Bridgeport
tonight.

i