Custom Post Processor for GRBL

[Strooom]

The 'Generic GRBL' Post Processor in Autodesk Fusion360 isn't really well optimized or adapted to GRBL, so I decided to modify it and try to make a more user-friendly and robust PostProcessor for GRBL based machines. I tested on an Openbuilds OX with Makita RT0700 but I think it should work well on ShapeOko's and XCarve as well..

A few of the immediate advantages :

• doesn't write a M6 T1 toolchange (which GRBL doesn't handle)
• at the end of the job, moves spindle up, shuts down spindle then moves to machine origin
• a comment block at the beginning gives an overview of operations, tools, and spindle speeds
• translates spindle RPM to a 1-6 dial setting for those who use a Makita RT0700 or similar spindle (Dewalt 611, Bosch Colt)

Get it from https://github.com/Strooom/GRBL-Post-Processor

[HughesTooling]

I tried to help someone out a while ago with a GRBL post, he was having a lot of trouble with G53 but a quick look at your post looks like the control should handle it fine. He infomed me that GRBL doesn't allow tool changes so I put a check in the post so it errors if someone tries to post 2 or more tools, don't know if that's correct but if it is you might want to add something similar to your post.

Here's a link to the other thread.

http://forums.autodesk.com/t5/post-processors/mach3-post-am-i-doing-something-wrong/td-p/6413742/hig...

Mark

[Strooom]

Thanks Mark, I'll take a look and merge the best of both!

[Strooom]

Hi Mark,

could you take a look on my further questions here : https://forums.autodesk.com/t5/hsm-post-processor-forum/cam-g-code-issue-with-mach3-post-processor/m...

The Openbuilds postProcessor is quite succesful, but it has an issue with very small arcs. I'm trying to solve that, but I need more info on some of the builtIn functions...

thanks.

Pascal

[metalnorte.ba]

My machine is Atmega 2560 arduino with GRBL.
I have a problem with my spindle as it doesn´t turn on when I execute the job. Everything works but not the spindle.
Can anyone help me? 

[Strooom]

Hi,

if you see an M3 or M4 in the gCode output, then the post-processor is generating the correct gCode.

Also check that the spindle speed is not 0 (zero), turning on a spindle at 0 rpm does not turn it on. So check your gCode for the S-word, ideally it should occur before the M3 or M4

If the gcode is correct, then there may be some electrical problem in your machine, for this you should ask support on eg the openbuilds forum.

succes !

[marc5KGCS]

NexGenCAM... Those guys do an awesome job with Post Processors    https://nexgencam.com/