G73 Chip break Drilling cycle

                                             The gcode G73 chip breaking cycle works same as deep hole drilling cycle G83and is also known as peck drilling cycle. But In this cycle the drill will not be retracted to the clearance position of the hole, the drill will retract only to specified height after drilling the certain depth of cut keeping the drill inside the hole. This cycle retracts to the specified height after each peck of drill and repeated until the total depth of the hole is achieved.

                The cycle G73 is used for the long series of the drills where we can expect the vibration of the tool and it can damage the hole and the tool. G73 cycle keeps the tool inside the hole until the drilling operation is completed and saving the time on the cycle.

Code line for G73 Chip break drilling cycle:

N100 G98 (G99) G73 X… Y… R… Z… Q… F…

Diagram for G73 Chip break drilling cycle:

Steps for the G73 Chip break drilling cycle:

 1.       Rapid motion to XY position of the hole position.

       2.       Rapid motion to the R level, i.e., to the top of the hole position.

       3.       Feedrate motion to the depth by the amount of Q value in Z.

       4.       Rapid retract to Clearance value Specified.

       5.       Feedrate motion in Z axis by the Q amount plus the clearance value.

       6.       Point number 4 and 5 repeated until the z depth of the hole is reached.

       7.       Rapid retract to the initial level (with G98) or Rapid retract to R level (with G99).