LinuxCNC and Crossfire Controller

Has anyone had success or made any progress in controlling the crossfire plasma table using LinuxCNC?

1 Like

Interested too - subscribing to this thread

FWIW, I did play with using LinuxCNC to drive the Mach3 USB controller board and it’s pretty straightforward. It wouldn’t work for the FireControl board as it’s interface isn’t ‘open’ (as far as I know although there was a post implying that FireControl is built on GRBL), and there are some proprietary commands that would need to be placed in the appropriate LinuxCNC post processor.

My conclusion is that this wouldn’t take a big effort, but it does beg the question as to why do it? If you have a system, then you already have some controller software for it. Why create a new one, UNLESS, you are also replacing the controller board. This was the track I was on.

My thought was to replace the CrossFire Org controller board with a BeagleBone Black with MachineKit. This is the platform I have on my CNC router and I like it. It runs Debian Linux, I can run the console remotely using VNC, and, most importantly, the Motion Control software runs on the PRU, which is an independent core running in real-time without the Linux OS preempting it. So motion is smoother, more accurate, and faster stepping (although this doesn’t really matter with the Plasma Cutter table).

Is it still on my ‘to do’ list? Not really. My CF works and I’m doing useful stuff with it - why fix something that isn’t broken? I can buy a replacement Mach 3 USB board for $30 or less if need be. It’s an ‘academic’ interest, but I’ve got a bunch of more compelling time sinks ahead of it.

I’ll add, if Mach 3 ever took the Autodesk (or Sketchup, etc, etc, etc) route and tried to go to a Subscription model, then this decision would be easy! That’s not likely to happen, but worth mentioning only to send ‘annoyance’ karma out into the ether…

1 Like

The FireControl compatible controller (used on the PRO and now on the CrossFire) is a GRBL controller, slightly modified to accommodate a plasma cutter. You can confirm this by simply connecting to it with a terminal program and typing a GRBL command like “$$” (the baud rate is 115200). Or type CTRL+X which will restart GRBL and print the ID string. For this reason, it does not really make sense to use LinuxCNC with it. If you want to use something other than FireControl, there a number of Gcode streaming programs that should work. The plasma table is not a particularly demanding CNC application and I doubt you’d see any real difference between GRBLs performance and that of MachineKit on the BBB with it.
For those interested, the control board is effectively an Arduino UNO constructed with connectors that make sense for a CNC machine. In addition it contains a Cypress 2-port USB hub, which allows for the single USB connection to the PC to talk both to the Arduino and the THC if it is installed.

1 Like

Agree re performance. The advantage of the MachineKit implementation is that it replaces not only the control board but the PC as well making it totally self contained. You SSH your design files to it and run.

Thanks for confirming the GRBL implementation.

1 Like

Thanks @TomWS and @rlkeck for your insights. I run a community makerspace, and my primary reason for wanting this is for a consistent user interface across all CNC machines. All machines using the same interface means less training and easier maintenance. And similar to Tom, I find it preferable.

But maybe I asked the wrong thing originally. I don’t care to replace the hardware, I really just want to use the Axis GUI instead of Mach3. Does anyone know if this is possible with a GRBL controller or would a hardware replacement be necessary?

I doubt Axis will run a GRBL controller. For one if it could, the developers would probably mention it. The other reason is LinuxCNC does have more features than GRBL. GRBL is clearly aimed at machines that are mainly 2 or 2.5 axis like 3D printers, 2D plasma cutters, lasers and routers and does not support all the LinuxCNC gcodes.