cae-tools/drl2gp

Drill file (Excellon) to gnuplot conversion
===========================================

drl2gp converts drill instructions in KiCad-generated Excellon files
to tool paths in gnuplot notation.

drl2gp should be integrated into "cameo" (../cameo) at some point in
time.

This work is distributed under the terms of the GNU GENERAL PUBLIC
LICENSE, Version 2:

  This program is free software; you can redistribute it and/or modify
  it under the terms of the GNU General Public License as published by
  the Free Software Foundation; either version 2 of the License, or
  (at your option) any later version.

For your convenience, a copy of the complete license has been included
in the file COPYING.GPLv2.


Usage
-----

drl2gp reads a drill file and generates toolpaths for a specific tool.
Instructions that cannot be executed with the specified tool, e.g.,
holes smaller than the tool's diameter, are ignored. 

To facilitate iterative generation of toolpaths, drl2gp can generate a
copy of its input file from which the instructions it has turned into
toolpaths are removed. A typical workflow would then consist of a
series drl2gp runs with drill, followed of a run with an endmill.

drl2gp adjusts toolpath for the tool diameter. It is therefore not
necessary to run "cameo" on the toolpaths.

Usage:

  drl2gp depth drill_d_min drill_d_max <file.drl >toolpaths.gp
  drl2gp depth mill_d <file.drl >toolpaths.gp

"depth" is the depth to which to drill. The tool can either be a drill
or an endmill. A drill makes holes efficiently but cannot be moved
sideways. An endmill can be used to cut holes wider than the tool
diameter and it can cut slots.

For a drill, the minimum and the maximum diameter of holes it should be
used for is specified. For an endmill, the tool diameter is specified.

All dimensions are in millimeters by default. The unit can be set to mil
with the option -i and set back to millimeters with -m. -i and -m can be
repeated any number of times and affect the parameters following them.

If the option  -f out.drl  is given, drl2gp writes a copy of the
Excellon file from which the drill instructions that have been accepted
in this run have been stripped.

Example:

  drl2gp 1 -i 10 15 <file.drl -f tmp.drl >drill-135.gp
  drl2gp 1 0.8 <tmp.drl >mill-08.gp

Here, first generate toolpaths for a 13.5 mil drill. We use this drill
for all holes with a diameter from 10 to 15 mil. Second, we use a 0.8
mm endmill for the remaining drill instructions.


Known bugs
----------

- most of the elements in an Excellon file are just ignored, without
  examining if some may have an effect

- when encountering a slotting operation with a compatible tool diameter,
  drl2gp tries to process it even if the tool is a drill. This gets
  detected when trying to generate the toolpath and results in an
  assertion failure.

  As work-around, choose the endmill in a set of tools such that it is
  suitable for all slots, and only use drills smaller than the smallest
  slot. (drl2gp will then use the endmill for everything that's left
  after the drills.)

- drl2gp should warn if any drill instructions are left for which no
  toolpath could be generated (if not using -f)