Compatibility with Lantek and other high-end software

Hello
I've posted in general linux cnc about modifying lantek post processor to support qtplasmac or other linuxcnc interfaces.

I've came across two lantek versions which export a gcode in different ways, like the files posted in attachment.
The price will, probably be very expensive to create a dedicated post-processor, but the already exported gcode could be modified.

The idea by user rodw, would be to modify qtplasmac filter, in order to automatically modify these files to add the material number, and the qtplasmac supported commands.
these machines used to be made with dc motors on Z axis, but now use stepper motors.
M3 on qtplasmac handles all pierce operations so it should be fairly simple to modify these files, even with a python script, to be usable in linuxcnc, right?


 

Actually, what I was proposing was some kind of plugin interface to the QTplasmac filter that allowed an input file to be converted on the fly to support qtplasmac's requirements.

This could be quite cool as it would let QTplasmac to be driven by high end nesting systems that do not have postprocessor support or an affordable way to obtain a customised post processor.

I have done some experimental work on the filter and it is relatively easy to call in a python script from the config directory and enable custom filtering by either additional procedures or overriding existing procedures.There are some issues with the posted ngc files though:

• 100x100rectangle.txt - has quite a few codes unknown to LinuxCNC, you would need to resolve what they did on the particular machine they were written for.
• gcodeLantekJM.txt - has issues with the arcs, the first two give the error "Radius to end of arc differs from radius to start", I didn't try any others.

They both seem to use cutter compensation which means you cannot use g-code thc, velocity based thc or over cut.

The attached file is gcodeLantekJM.txt roughly converted with a custom filter, with the above noted arc issues.

I am happy to push a test branch if you want to experiment.

 

hey phillc,

I'm writing a python script that will remove all G41 M21, G40 M20 entries and replace them with typical arc start and arc end... also remove all N(xx) number of line entries, and imprint the initial conditions on the file.

What do you need to do to correct the arcs? I'm not sure i understand.

Also, do you put this to get the kerf width right after every M3 command automatically? G41.1 D#<_hal[plasmac.kerf-width]>

Could you share the script you used to get that code? I'm going to test it on the qtplasmac next monday

The arcs possibly have incorrect I or K values. I maxed out CENTER_ARC_RADIUS_TOLERANCE_MM in the RS274 section of the ini file and it didn’t help.

The G41.1 line replaces the G41 lines, if you remove them then the cut size will be incorrect as there will not be any cutter compensation.

The script I used can only be used in association with the existing filter that has been modified to call the script.

Could Lantek be configured to do kerf compensation in the post processor? Sheetcam and Fusion 360 support this sso you would expect high end software would also.