| modified: | 2018-11-26 |
|---|---|
| Date: | 2018-01-23 |
| Author: | Roland Smith |
Note
As of November 2018, the Gerber cloth cutter for which I wrote these programs is being retired. As a consequence, I will not spend a lot of time improving the programs anymore, and the github repo will be archived.
These programs and modules were created because the existing software to generate NC code for our gerber cloth cutter has some deficiencies.
Note that this software was _not_ written for Gerber PCB milling machines! The generated code was tested on a Gerber Garment Technology S-3000 cutter, with the C-200MT controller software.
Most programs use the nctools modules. The dxfreader submodule can extract LINE,
ARC, CIRCLE and POLYLINE entities from a DXF file. Note that it does not
handle other entities like BLOCK. The module _assumes_ that the units in the
file are millimeters. It also only writes nc code in centi-inches.
At this time these programs are going through a rewrite, done on the ‘develop’ branch.
- Python 3. (Developed with Python 3.4 and 3.5)
- the
cairolibrary and its python bindings fordxf2pdfandnx2pdf
Run ./setup.py install.
These programs are command-line utilities. There are no GUI front-ends planned at the moment.
All these programs can read files in other directories. They will however only write files in the current working directory. The output filename will be generated from the input filename by removing any directories and the extension. Where necessary, new extensions and/or modifiers are added. So an input file '..foobar.dxf' will generally result in an output file named 'bar' with the appropriate extension.
To try the programs without installing them, run:
python3 -m nctools.<program> <arguments>
from the root directory of the repository. Every program supports the -h
or --help options for an overiew of the arguments and usage.
The cutworks software that comes with a gerber cutter doesn't automatically optimize the cutting paths it reads from dxf files. It essentially cuts lines in the order it finds them in the dxf file.
This program reads a dxf file. The name of the file must end in .dxf or .DXF otherwise the program will report an error and quit. It extracts all the LINE, ARC and POLYLINE entities from it. It then searches through all these entities and assembles connected entities into lists called contours. If necessary, the direction of entities in a contour is changed so that all entities can be cut in one continuous movement.
These contours and any remaining lines and arcs are then sorted as given by the options. The default is to sort first in ascending x and then in ascending y.
The machine that these programs were originally written for is an older machine, whose controllen doesn't even understand arcs, only straight lines. So it also converts arcs into line segments. By default the length of these segments is such that the deviation from the curve is not more than 0.5 mm. It ignores the $MEASUREMENT variable in the dxf file because that is often not set correctly and assumes that the units in the dxf file are millimeters.
Gerber numeric code files are basically text files but do not contain line
breaks, which makes them hard to read. The readnc utility can be used to
display the file in a more human-readable format.
The software for our machine doesn't use extensions for nc files, so this program just strips the dxf extension from the filename.
This program reads a DXF file and generates a PDF file from it. This comes in handy to view a PDF file. The lines, arcs and polylines from the DXF file are shown on top of a 100x100 mm grid. Optionally the beginning and ending of lines are marked.
In this case, the output filename for the input file 'foo.dxf' will be 'foo_dxf.pdf'
The cutworks software that comes with a gerber cutter doesn't automatically optimize the cutting paths it reads from dxf files. It essentially cuts lines in the order it finds them in the dxf file. This was the original program to optimize DXF files for use with the Gerber software. It assembles connected lines/arcs into contours so that the cutter won't jump all over the part. The dxf2nc program is intended as its replacement.
Since the output of this command is also a DXF file, the output filename has '_mod' appended. So the input file 'baz.dxf' has the associated output file 'baz_mod.dxf'.
This program reads a Gerber NC file and plots the cuts as a PDF. It assumes units of 1/100 inch and only reads knife up/down and movements. It colors the cuts to indicate their sequence in the nc file.
In this case, the output filename for the input file 'foo.nc' will be 'foo_nc.pdf'
Gerber numeric code files are basically text files but do not contain line breaks, which makes them hard to read. This utility can be used to display the file in a more human-readable format.
Example output:
/Reading file 'test/gerber-busgang-csm.nc'./ /This file contains 1549 blocks./ H1 /file #1/ M20 /message/ Bus-CSM2/L=62.992/W=37.795 N1 /piece #1/ M15 /knife up/ X0Y0 /move to x = 0 mm, y = 0 mm/ M14 /knife down/ X3150Y0 /move to x = 800 mm, y = 0 mm/ M15 /knife up/ M14 /knife down/ X6299Y0 /move to x = 1600 mm, y = 0 mm/ M15 /knife up/ M14 /knife down/ X6299Y3780 /move to x = 1600 mm, y = 960 mm/ M15 /knife up/ ...
Reads a DXF file and outputs the entities that it finds. This is more of a debugging tool for the nctools module than a really useful program. It gathers entities into contours for testing purposes of that functionality. A visual alternative would be to use dxf2pdf.
Example output:
Filename: testfiles/snijden-CSM1.dxf
Contains: 425 entities
Layer: "deel 1"
LINE from (0.00, 0.00) to (1198.75, 0.00)
LINE from (962.37, 311.26) to (1222.77, 311.26)
LINE from (1198.75, 0.00) to (1175.54, 311.26)
LINE from (599.38, 1249.19) to (1222.77, 1249.19)
LINE from (599.38, 1249.19) to (217.77, 1249.19)
LINE from (1222.77, 1249.19) to (1222.77, 311.26)
LINE from (59.57, 1249.19) to (0.00, 0.00)
LINE from (217.77, 1249.19) to (59.57, 1249.19)
LINE from (480.69, 806.18) to (722.56, 806.18)
LINE from (688.18, 1017.93) to (462.11, 1018.39)
LINE from (462.11, 1018.39) to (480.69, 806.18)
LINE from (712.90, 990.25) to (722.56, 806.18)
POLYLINE
VERTEX at (712.90, 990.25)
VERTEX at (712.89, 990.49)
VERTEX at (712.87, 990.74)
VERTEX at (712.85, 990.99)
...
VERTEX at (688.42, 1017.89)
VERTEX at (688.18, 1017.93)
ENDSEQ
LINE from (811.74, 1141.23) to (387.01, 1141.23)
LINE from (387.01, 641.28) to (811.74, 641.28)
LINE from (256.88, 1011.10) to (256.88, 771.40)
LINE from (941.88, 771.40) to (941.88, 1011.10)
ARC from (387.01, 1141.22) to (256.88, 1011.10)
centered at (387.01, 1011.09), radius 130.13, from 90.0° to 180.0°
ARC from (256.88, 771.40) to (387.01, 641.28)
centered at (387.01, 771.41), radius 130.13, from 180.0° to 270.0°
...
You will need py.test to run the provided tests. Code checks are done using pylama. Both should be invoked from the root directory of the repository.