Pocketing Example

For another example, assume that you want to generate a pocket milling cycle from the geometric information on a line.  Since lines are set up to generate a G01 or LINEAR move, a second motion block definition is needed.

The $PP file would need the following entries:

SEQNO#PB#LINEAR#RAPID#X#Y#Z#PA=$LINE1.1

SEQNO#POCKET#XI#YI#PDEPTH=$LINE2.1

G00;D#LINEAR;E#RAPID=RAPID

G01;D#RAPID;E#LINEAR=LINEAR

X#3.4=X

Y#3.4=XI

Y#3.4=YI

G72;G#2#1=POCKET

Z#3.4=PDEPTH

The 'G' switch on the G72 code causes the postprocessor to switch to group number 2 for NC code output.  Additionally the code also causes the group number to change back to 1 when the code is output to the NC file.  This provides the ability to output a pocket cycle from a line and then switch back to the normal G00, G01 interpretation of a .DXF line.  If you want to output a pocket cycle for each line, define the switch as "G#2#2", which causes the postprocessor to use group 2 definitions until switched back.  You can build a code to switch back to group 1 by adding the entry:

;G#1#1=GROUP1

to the $PP file.  Whenever the text statement "GROUP1" is processed, no output will be generated, but the 'G' switch will still be implemented changing the group number to 1.

Example:

 

Note that even though G01 line output is in absolute mode, the group 2 definition for a line uses the incremental geometric entries "XI" and "YI" in order to form the correct values for the X,Y pocket milling cycle.