[Pcb2gcode-devel] pcb2gcode oddities

[John B. <joh...@gm...>]

I'm not calling these bugs because the program works, but they might help
other people who are running into the same problems I ran into and they
might be things the developers might want to change.  I'm running pcb2gcode
1.1.2 on ubuntu 11.04

1.  If there's a millproject in the directory, pcb2gcode seems to use it,
even if it's not asked to.  If I run pcb2gcode --front="front.gbr" [lots of
options] and I have a millproject around that contains an
"outline=outline.gbr" line, I get an outline.ngc as well as front.ngc -- and
in that case it's obvious what's happening, but if the only difference is
something like offset=0.003 when millproject has an offset=0.010, that's
more difficult to track down.

2.  When I run, let's say, "pcb2gcode --front "driver.front.gbr"
--cutter-diameter 0.004 --zcut 0.007 --cut-feed 10 --cut-speed 20000
--cut-infeed 0.007 --zsafe 0.025 --mill-speed 20000 --mill-feed 10 --offset
0.004 --zchange 2.00 --zwork 0.004" I get a good front.ngc output, with a
good toolpath.
If I then run " "pcb2gcode --front "driver.front.gbr" --cutter-diameter
0.004 --zcut 0.007 --cut-feed 10 --cut-speed 20000 --cut-infeed 0.007
--zsafe 0.025 --mill-speed 20000 --mill-feed 10 --offset 0.004 --zchange
2.00 --zwork 0.004 --outline "driver.outline.gbr" -- just adding the one
extra parameter that has it process a second file -- the front.ngc is
essentially blank.  It has a 5-item preamble, issues a G64, a G04 P0, a G00
Z2.0000, an M9, and an M2, and that's it.  The same thing happens when I add
all the relevant parameters for the outline cutter, or if I have a
driver.back.gbr that I try to isolate along with the front.
So if I want to get good front and back isolation files I need to run each
of them separately, and then run the drill and outline files.
It works just fine when I do that... but since it can process multiple
files, and produce outputs, it took me a while to figure out why I was
getting blank front and back isolation layers, which might be confusing to
other beginners.

I've had exactly the same thing happen with any millproject file I've used,
but I haven't actually tried a millproject that just works on one layer at a
time.

Anyway.  When I crank out one layer at a time it works great and the output
is lovely, and it's awesome to be able to mill my own PCB's, so thank you
very much for making this piece of software.