Options%3A Drilling - pcb2gcode/pcb2gcode GitHub Wiki
pcb2gcode can convert an Excellon File Format drill file to gcode instructions for your CNC.
These are the options are are useful for drilling:
Drilling options, for making holes in the PCB:
--drill arg Excellon drill file
--milldrill [=arg(=1)] (=0) [DEPRECATED] Use min-milldrill-hole-dia
meter=0 instead
--milldrill-diameter arg diameter of the end mill used for
drilling with --milldrill
--min-milldrill-hole-diameter arg (=inf)
minimum hole width or milldrilling.
Holes smaller than this are drilled.
This implies milldrill
--zdrill arg drilling depth
--zmilldrill arg milldrilling depth
--drill-feed arg drill feed in [i/m] or [mm/m]
--drill-speed arg spindle rpm when drilling
--drill-front [=arg(=1)] [DEPRECATED, use drill-side instead]
drill through the front side of board
--drill-side arg (=auto) drill side; valid choices are front,
back or auto (default)
--drills-available arg list of drills available
--onedrill [=arg(=1)] (=0) use only one drill bit size
--drill-output arg (=drill.ngc) output file for drilling
--nog91-1 [=arg(=1)] (=0) do not explicitly set G91.1 in drill
headers
--nog81 [=arg(=1)] (=0) replace G81 with G0+G1
--milldrill-output arg (=milldrill.ngc)
output file for milldrilling
There are two ways to make holes in your board:
- Use drill bits and drill straight through. This is called "drilling".
- Use milling bits and carve out the holes. This is called "milldrilling".
Drilling is the usual way and important for small holes which can otherwise not be milled because they are smaller than a milling bit diameter.
Milldrilling is more useful for large holes that are larger than the milling bit. Also, a single milling bit can do any size that is at least as big as the milling bit.
G85 slots (specification)
pcb2gcode supports G85 Excellon slots. To use this, you'll need a version of gerbv that supports it, at least 2.6a. If you don't have a version of gerbv that supports slots and try to use slots, warnings will appear when running pcb2gcode.
Drilled slots are made by drilling many successive holes. The number of holes is sufficient to meet that spec requirements of protrusions less than 0.0005 inches. Milldrilled holes are made by milling oval shapes deeper and deeper into the PCB.
It's possible that your input has many drill sizes, some very similar. For example, you might have:
- 0.498mm holes
- 0.501mm holes
- 1.000mm holes
- 1.020mm holes
pcb2gcode will ask you to change drill bits after each tool change, even if the drill bit that you would use for 0.498 and 0.501 are probably the same drill bit! To solve this, you can specify available drills. For example, if you have a 0.5mm drill bit and a 1.0mm drill bit, you could write:
--drills-available=0.5mm,1mm
And holes near those sizes would get rounded to those specified sizes.
If you want, you can limit the rounding, too. For example:
--drills-available=0.5mm:0.1mm,1mm:0.01inches
Now only holes within 0.1mm of 0.5mm will be rounded to 0.5mm. And only holes within 0.01inches of 1mm will be rounded to 1mm. If you want to specify both the upper and lower bounds:
--drills-available=60thou:-7thou:+5thou
Holes between 53 thou and 65 thou will be drilled with the 60 thou bit.
These are snippets that you might put in your milldrill file.
drill=my_project.drl
milldrill=false # Turned off to use drilling (default)
#milldrill-diameter=2mm # Unused
#min-milldrill-hole-diameter # Unused
zdrill=-1.6mm # PCB is 1.4mm but drill an extra 0.2 mm to make sure to go clean through
drill-feed=500mm/minute # How fast to plunge the drill bit
drill-speed=10000rpm # How fast to spin the drill bit
drill-side=auto # Let pcb2gcode choose which side to drill and report the results in the output
#drills-available # Unused
onedrill=false # Use many different drill sizes (default)
#drill-output=drill.ngc # Drilling output filename (default)
#milldrill-output=milldrill.ngc # Milldrilling output filename (default)
Same as drilling but change these:
milldrill=true # Turned on to use milldrilling
milldrill-diameter=2mm # Milling bit is 2mm wide
#min-milldrill-hole-diameter # Unused
zcut=-0.13inches # Mill away 0.13 inches each pass
Same as drilling or milldrilling but use a much smaller depth to make a small indentation.
zdrill=-0.2mm # Just leave a mark for the drill press later
onedrill=true # All the pilot holes can use the same drill
Combine the milldrill and drilling configurations from above and add this:
min-milldrill-hole-diameter=2mm # Holes 2mm or above are milldrilled, the rest are drilled
The default milldrill depth is the same as zdrill but you can override it with zmilldrill.
zdrill=-0.2mm # Just leave a mark for the drill press later
zmilldrill=-1.6mm # milldrilling all the way through the PCB