peck drilling cycle
The G73 code word calls the peck drilling cycle. This is a method of drilling that takes small cuts into the work piece, rapid retracts a small amount to break the chips, rapids back to the last Z depth, makes another small cut, retracts again, and so on until the full Z depth has been reached. This is used to keep the flutes unclogged, avoid stringers , and to keep the drill cooler.
G73 X0Y0 R.06 Z-1 Q.03 F20 G98
R is the code word for the rapid plane, Z is the depth, Q is the amount of each peck, F is the feed rate, and G98 is included in the block to retract to the initial plane. Note: the amount that the drill retraction is a parameter set in the controller and is not programmable. It is usually about .005 on most machines.