- Example of a granular pyramid form, aka 'square vector orbit' CCW path

As each motion is completed, an inverse of that motion is placed on a 'reverse path stack'.

break out your quadrule paper and pencil and ture it...

the original program's N numbers are used for reference

Original Pgm Retract Pgm (abort was in N190) Return Pgm ( all clear in N120 ) Continued Pgm N010 G90 N999 G90 N998 G90 N010 G90 N020 G00 X 0.000 Y 0.000 Z 0.000 N180 G01 X 0.020 Y 0.000 Z-0.020 N130 G01 X-0.010 Y-0.020 Z-0.020 N190 G01 X 0.020 Y 0.010 Z-0.020 N030 G01 X 0.010 Y 0.010 Z-0.010 N170 G01 X 0.020 Y-0.010 Z-0.020 N140 G01 X 0.000 Y-0.020 Z-0.020 N200 G01 X 0.020 Y 0.020 Z-0.020 N040 G01 X 0.020 Y 0.020 Z-0.020 N160 G01 X 0.020 Y-0.020 Z-0.020 N150 G01 X 0.010 Y-0.020 Z-0.020 N210 G01 X 0.010 Y 0.010 Z-0.010 N050 G01 X 0.010 Y 0.020 Z-0.020 N150 G01 X 0.010 Y-0.020 Z-0.020 N160 G01 X 0.020 Y-0.020 Z-0.020 N220 G01 X 0.000 Y 0.000 Z 0.000 N060 G01 X 0.000 Y 0.020 Z-0.020 N140 G01 X 0.000 Y-0.020 Z-0.020 N170 G01 X 0.020 Y-0.010 Z-0.020 N230 M02 N070 G01 X-0.010 Y 0.020 Z-0.020 N130 G01 X-0.010 Y-0.020 Z-0.020 N180 G01 X 0.020 Y 0.000 Z-0.020 N080 G01 X-0.020 Y 0.020 Z-0.020 N120 G01 X-0.020 Y-0.020 Z-0.020 N190 M02 process becomes ok in N120 N090 G01 X-0.020 Y 0.010 Z-0.020 N110 G01 X-0.020 Y-0.010 Z-0.020 we're back at N190, N100 G01 X-0.020 Y 0.000 Z-0.020 N100 G01 X-0.020 Y 0.000 Z-0.020 The 'run mark is set to N190 N110 G01 X-0.020 Y-0.010 Z-0.020 N090 G01 X-0.020 Y 0.010 Z-0.020 in original program and N120 G01 X-0.020 Y-0.020 Z-0.020 N080 G01 X-0.020 Y 0.020 Z-0.020 we run the original next. N130 G01 X-0.010 Y-0.020 Z-0.020 N070 G01 X-0.010 Y 0.020 Z-0.020 N140 G01 X 0.000 Y-0.020 Z-0.020 N060 G01 X 0.000 Y 0.020 Z-0.020 N150 G01 X 0.010 Y-0.020 Z-0.020 N050 G01 X 0.010 Y 0.020 Z-0.020 N160 G01 X 0.020 Y-0.020 Z-0.020 N040 G01 X 0.020 Y 0.020 Z-0.020 N170 G01 X 0.020 Y-0.010 Z-0.020 N030 G01 X 0.010 Y 0.010 Z-0.010 N180 G01 X 0.020 Y 0.000 Z-0.020 N020 G01 X 0.000 Y 0.000 Z 0.000 N190 G01 X 0.020 Y 0.010 Z-0.020 N010 M02 a bad process causes ABORT in N190 N200 G01 X 0.020 Y 0.020 Z-0.020 N210 G01 X 0.010 Y 0.010 Z-0.010 N220 G01 X 0.000 Y 0.000 Z 0.000 N230 M02

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_Original__Pgm_ | _Retract____Pgm_ | _Return____Pgm_ | _Continue__Orig_ |

so, if the program was aborted in the midst of line 190, the 'trick' is to run the reverse program that was auto built.

the example shows an 'all clear ( ok to proceed ) occur in N120 this cause the return program to end, and we'll want to continue, with the original program, but beginning at N190 (need to automate seeting the 'run mark' and knowing where to set it )

the above idea retraces the path, and is suitable for wire edm in wire edm even arcs could be automaticly translated to lots of linear moves (as seg q would)</pre>

- Sink and Hold drill dont require path reversal

they 'run-way' to a safe place. It may be on the path, but it's a static position. It's like sky-blue in hopscotch. No matter where you are in the program, its where you run away to. Original Pgm Reverse Pgm (abort was in any line) Return Pgm ( all clear in N120 ) N010 G90 N999 G90 N998 G90 N020 G00 X0.000 Y0.000 Z0.000 N180 G00 X0.000 Y0.000 Z0.000 N130 goto line WhereverTheAbortOccured N030 G01 X0.010 Y0.010 Z-0.010 N010 M02 N040 G01 X0.020 Y0.020 Z-0.020 just run away to top of pyramid just return to the line that was aborted or wherever 'sky blue' is at the postion of abort N050 G01 X0.010 Y0.020 Z-0.020 (sky blue is a safe place) use the probe routines to capture the position N060 G01 X0.000 Y0.020 Z-0.020 also record the point where expand this for jump flushing N070 G01 X-0.010 Y0.020 Z-0.020 the abort occurred ...as before... N230 M02

- Marking Safe Places

we might use a code to mark a pose as a safe place ( a waypoint ) allow differnt safe places during different parts of the program N010 G90 N012 G00 Z 2.000 ; get high over clamps N014 G00 X 0.000 Y 0.000 ; get over the start position N016 G00 Z 0.04 M101 ; get close and mark this as a safe place to retract to N018 M36 ; turn on EDM power and change to new feedrate mode N020 G00 Z-0.990 M101 ; mark this as the 1st position to run towards when things get bad, old 1st is 2nd N030 G01 X 0.010 Y 0.010 Z-1.000 N040 G01 X 0.020 Y 0.020 N050 G01 X 0.010 N060 G01 X 0.000 ; if things get bad here, run to posN020, N070 G01 X-0.010 ; if we arrive at posN020 and it's still bad, go towards posN016 ; if posN016 is arrived and things are still bad, give up! no place to run to! ...as before... N230 M02