LinuxCNC vs GRBL on a microcontroller - Page 1
Forum section: electronics / general

author: Infraviolet
author_rank: Super Contributor
timestamp: October 26, 2022, 07:00:57 pm
content: I'm in the early stages of planning out a small CNC mill build idea. I've been looking in to software options, with the requirement that they be open source products which aren't dependent on cloud or any other non-local infrastructure. It seems to my understanding that two of the common options meeting these requirements are GRBL and LinuxCNC, the former running on an arduino board of some type or other microcontroller, the latter needing a PC or raspberry Pi dedicated to running the CNC machine. But I've also found that neither of these does gcode generation to convert your stl file to toolpaths (the way a slicer does for 3d printing), they just do the gcode interpretation, and you have to look for other software options to produce toolpaths. So, as neither of these "firmware" type programs does the gcode generation, what level of difference can they actually provide? My understanding is GRBL is quicker and simpler to set up, but less "feature rich", but what features can you really have in smething which just reads gcode and moves a tool according to it, don't fancy features all happen at the model-to-gcode conversion stage?Thanks

author: thm_w
author_rank: Super Contributor
timestamp: October 27, 2022, 10:08:36 pm
content: Maybe you can find some tutorial videos or explanations that will help you understand.The CNC controller software (GRBL board or linuxCNC), takes gcode and converts it into various inputs and outputs (motor commands, etc.).If you have something fairly simple like a laser cutter, that just cuts in a 2D path, at x speed, y brightness, you may not need any sort of user interface and a basic GRBL board is fine.If you have an advanced CNC machine, where you want to calibrate tool bits, probe points, toggle flood coolant, etc. and see this info on a large screen, GRBL might not be enough.https://howtomechatronics.com/tutorials/how-to-setup-grbl-control-cnc-machine-with-arduino/https://all3dp.com/2/grbl-software-guide/https://www.eevblog.com/forum/beginners/cnc-grbl-for-pcb-millinghttps://www.eevblog.com/forum/mechanical-engineering/gbrl-why-the-mysteryThe CAM software is what you use to generate toolpaths like as slicer as you say. But its more of a manual process than a slicer.Fusion360 should have a free CAM option:https://www.instructables.com/Fusion-360-CAM-Tutorial-for-CNC-Beginners/

author: tatel
author_rank: Frequent Contributor
timestamp: October 27, 2022, 11:13:45 pm
content: https://forum.linuxcnc.org/31-cad-camhttp://wiki.linuxcnc.org/cgi-bin/wiki.pl?Cam

author: langwadt
author_rank: Super Contributor
timestamp: October 27, 2022, 11:54:56 pm
content: Quote from: thm_w on October 27, 2022, 10:08:36 pmthose are a function of the UI used, and you can do all that with grblbut no doubt that linuxcnc have many more and more advanced features than grbl

author: Infraviolet
author_rank: Super Contributor
timestamp: October 28, 2022, 12:19:41 am
content: Thanks for that. For CAM I'm considering PyCAM( open source, locally run and linux PC compatible), or FreeCAD IF it can do CAM on imported stls not only on models built in FreeCAD. Definitely won't be placing any reliance on cloud-dependent Fusion360 though.Links are useful, but some of the eevblog links about GRBL go to 404s though.

author: langwadt
author_rank: Super Contributor
timestamp: October 28, 2022, 12:27:07 am
content: Quote from: Infraviolet on October 28, 2022, 12:19:41 amthe CAM i F360 is awesome though and you are not going to find anything anywhere near it for lessSTL is not very common for CNC milling, you have any experience with CAM other than stl to 3 printer? CAM for a cnc mill is nothing like that

author: thm_w
author_rank: Super Contributor
timestamp: October 28, 2022, 01:15:52 am
content: Quote from: langwadt on October 27, 2022, 11:54:56 pmYeah looks like it is available with this android UI for example:https://zeevy.github.io/grblcontroller/probing-and-tool-length-offset.htmlhttps://winder.github.io/ugs_website/Might be enough for most machines.

author: IconicPCB
author_rank: Super Contributor
timestamp: January 09, 2023, 10:49:30 pm
content: Check whether GRBL understands all or some G codes. Same for LinuxCNC.

author: langwadt
author_rank: Super Contributor
timestamp: January 09, 2023, 10:53:54 pm
content: Quote from: IconicPCB on January 09, 2023, 10:49:30 pmlinuxcnc should do just about everything and more, grbl is a subsetbut you are using e.g. the grbl postprocessor in F360 you only need that subset