Can we feed any .nc file to Carbide Motion? + Q's about GCode

I’m starting to get a feel for the different CAD and CAM programs out there, and was wondering - if I export a GCode file from these programs, will it be compatible with Carbide Motion?

And if so (and also, in general) - can someone give me an idea as to how I can interpret the GCode itself? For example, if I want the spindal to turn at 5000rpm - where would I locate this in the GCode to ensure that it’s correct? Likewise, what am I looking for in terms of identifying potential problem areas?


We have some basic information about G-code over on the Shapeoko wiki: w/ specific notes on which commands are supported by Grbl (which is the G-code interpreter which the Carbide Motion Microcontroller board runs).

You may find some of the programs and references at: of interest as well.

Here’s another question - I am playing around with Easel and exporting the GCode.

When I run the code through a simulator (I’m using OpenScam - thanks for the reference!) the Z axis is reversed. So the tool plunges to the bottom of the material and then starts to machine upwards to the top.

Any idea why this happens and how to adjust it in the GCode?

EDIT: Just found out from Jim Rodovich that OpenSCAM (weird name) sometimes runs the simulation files in reverse, which seems odd. I changed the direction of the cut (which I didn’t realize I had to do) and everything looks good.

I’m hoping that this GCode runs the Nomad without any problems. Easel is super easy to use!

Easel was designed to work w/ Grbl, so should work w/ the Nomad which also runs Grbl — might need to tweak some settings somewhere, but it should “just work.”

I hope it works okay - I want to do some 2d work and it’s so easy to use

Hi Darren,

You can import G-code into Carbide Motion from a number of different packages pretty easily, the important thing is having the Post Processor set correctly because Carbide Motion is NOT just a plain vanilla GRBL implementation, so there may be some things that are different, since Carbide is doing some leg-work in the middle before sending your code over to the GRBL board in the Nomad/Shapeoko.

Rob’s recommendation (and what I’ve been successfully using) is a Mach3 post, which you can get fairly easily for most CAM packages. I’ve been using it out of Fusion360’s integrated CAM tools, which are from HSMworks. The only option I change on the Mach3 settings at this point is to turn “use radius” OFF to force it to send all arc movements as arcs and not use the radius notation.

As far as resources for understanding what various g-codes mean, I’ve posted previously on a few details, and would recommend this g-code reference from Tormach. The Nomad and Shapeoko don’t support all of the functionality offered there (drilling cycles, tapping, etc…) but pretty much all the stuff that is used is there.

I’d suggest checking out Fusion360 if you want some really powerful options since it’s free for hobbyists/educational use, and the 2D options in it are really good, once you get through the learning-curve!