Small/single-board computers capable of running LinuxCNC?

Hello, I'm new to this forum, so I'm sorry if this has already been asked, or if I'm asking it in the wrong place.

I am looking to convert a very small, portable desktop mill to LinuxCNC. I would like to use a small computer that is built into the machine.

I was thinking of the Raspberry Pi, but I hear it's not powerful enough. Are there any very small (preferably single board) computers that are capable of running LinuxCNC smoothly? I'm looking for something similar in size to the Raspberry Pi (or slightly larger), and under $200.

MachineKit running on a BeagleBone is probably the most minimal hardware way of running ( something very close to ) LinuxCNC with step/dir drives, since MachineKit supports the PRU for step generation and LinuxCNC currently does not.

You can run LinuxCNC on a RPI but typically need additional hardware to support step/dir drives. There are some projects that use the RPI3s DMA to generate faster steps but I'm not sure of the status of these currently.

One basic issue with both the RPI and the Beaglebone and LinuxCNC/Machinekit is that they are quite slow and resource constrained relative to most X86 hosts so don't expect complex graphics to be smooth (or not run out of memory). I think MachineKit is further along on running only the realtime part of the machine control on the SBC and user interface on a more capable machine, but that architecture doesn't really save money or complexity on a minimal system.

For a tiny mill and minimal hardware (and no special features like rigid tapping), you might be better off with GRBL or some other microcontroller based CNC software.

Hi Peter,

since MachineKit supports the PRU for step generation and LinuxCNC currently does not.

If i read this. I think. Can i make a linuxcnc version with PRU possible?

I will have a look how to merge this Machinekit code reverse to Linuxcnc.
In other fact's i see that linuxcnc is behind scedule. This is not a good sign.

Thanks for the response. Are there any small computers that are powerful enough? I'm not very concerned about price, mostly just size. If I can spend 2-3x the price of a beaglebone or RPI, is there anything with good enough specs in a similar form factor?

I think one of the main 'gotchas' with using random SBCs and LinuxCNC is lack of hardware OpenGL support (if the backplot is important to you) and lack of real time I/O These are in addition to the difficulty of building a real time kernel on hardware that has SOC specific patches that have not been mainlined into the Linux kernel.

The advantage of using the Beagle Bone or RPI is that MachineKit and LinuxCNC are known to work on these platforms, slow though they are. Getting LinuxCNC and one of its GUIs to run well on one of the many newer more powerful SBCs is likely more of a project than you may want to undertake.

I suspect the easiest/cheapest current path for using a small SBC and LinuxCNC (or linuxCNC like software) is to use MachineKit on a Beaglebone since it does not require external stepgenerator hardware.

What type of drives are you planning on using?

Grotius wrote:

Hi Peter,

since MachineKit supports the PRU for step generation and LinuxCNC currently does not.

If i read this. I think. Can i make a linuxcnc version with PRU possible?

I will have a look how to merge this Machinekit code reverse to Linuxcnc.
In other fact's i see that linuxcnc is behind scedule. This is not a good sign.

Well LinuxCNC is ahead and behind of MachineKit (MachineKit has not incorporated the Joints Axis branch for example so its gantry support is kludgey but its support of SBCs and remote displays is better) That's what happens when you fork a project...

IMHO forking the project was harmful to both LinuxCNC and MachineKit

I am not sure what hardware I will be using. I'm new to CNC machining, but am fairly familiar with Linux.

My goal is to convert a friends small CNC mill to something that can be controlled with Linux, so other programs/computers can control/monitor (for example, a cell phone).

I don't know which drives he's using, but I can change them out. Perhaps I will try to find a non-single-board mini pc that is small enough, yet still powerful enough.