Script pygcode crop

Cropping Script

This script cuts out a portion of a gcode file so it may be executed independently of the rest of the file.

usage: pygcode-crop [-h] infile range

Remove gcode before and after given 'from' and 'to' conditions.

positional arguments:
  infile      gcode file to crop
  range       file range to crop, format [from]:[to] (details below)

optional arguments:
  -h, --help  show this help message and exit

Range Format:
    range must be of the format:
        [condition[,condition...]]:[condition[,condition...]]
    the first condition(s) are true for the first line included in the cropped area
    the second set are true for the first line excluded after the cropped area

    Conditions:
    each condition is of the format:
        {variable}{operation}{number}
    or, more specifically:
        [[{a,b,c,n,x,y,z}]{=,!=,<,<=,>,>=}]{number}

    Condition Variables:
        n     - file's line number
        a|b|c - machine's angular axis
        x|y|z - machine's absolute coordinate

    Example Ranges:
        "100:200" will crop lines 100-199 (inclusive)
        "z<=-2:" will isolate everything after the machine crosses z=-2
        "x>10,y>10:n>=123" starts cropped area where both x and y exceed 10,
            but only before line 123

    Limitations:
        Only takes points from start and finish of a gcode operation, so a line
        through a condition region, or an arc that crosses a barrier will NOT
        trigger the start or stop of cropping.
        Probe alignment operations will not change virtual machine's position.

Example Uses

Cut specific lines

cut out from line 100 to line 199 (inclusive) of the part.gcode file (yielding 100 lines)

$ pygcode-crop part.gcode 100:200

note: 200 is the first line excluded from the cropped region

also: the above line is equivalent to:

$ pygcode-crop part.gcode =100:=200
$ pygcode-crop part.gcode n=100:n=200

where n is the file's line number

Resume from depth

Let's say you have a pocket operation, but you had to stop it half way through (at a depth of 3.2mm). you can resume it by cropping out everything before Z reached -3.2mm

$ pygcode-crop pocket.gcode "z<=-3.2:"

note: as soon as < or > characters are used in the conditions, the range parameter must be expressed inside " quotes.

Only middle part

Or you're engraving 3 words stacked on top of each other, but you only want to engrave the middle word. The space between the top 2 words centres at y=3mm, and between the bottom 2 words is at y=6mm.

$ pygcode-crop engraving.gcode "y>3:y>6"

Multiple Conditions

You can also separate multiple conditions with ,s, they're all anded together. So in the engraving example, if you have 2 sets of 3 words:

Jane              foo
loves              bar
 John               roo

engraved in the order Jane, loves, John, foo, bar, and lastly roo. And the blank region in between engravings centres around x~=10

to just engrave bar you can crop it out with:

$ pygcode-crop engraving.gcode "x>10,y>3:y>6"