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If you have access to a PC with a parallel port, it's a cheap and easy way to get started in CNC using knockoff breakout boards from Amazon and some cheap stepper/driver kits. That's what I did. However, this is not a robust solution. I had many problems with port pins getting fried, for example. Getting any one of the Mesa cards (I used the 7i76E) is a bit more of an investment but the electronics are much more robust, and you get to enter the worlds of "industrial lego". At that point, you'd need LinuxCNC anyway, so might as well start there.

Also, it looks like GRBL is designed to run on an embedded board, not a PC, so if you want the lowest cost-of-entry, go LinuxCNC.

This is actually pretty easy, the 7i76e comes with 2 mpg inputs and you can have them on the 7i96 as well but you have to give up a couple of pins or a Stepgen.I can't quite remember what. If you ask PCW nicely, I'm sure he will sort out the correct solution.

Once you have that sorted, there is a good example of a MPG using parallel port pins in the docs. linuxcnc.org/docs/stable/html/examples/mpg.html

But in your case, you can ditch the axis select knob because you will use a dedicated MPG for each axis. Just implement the scale select knob... I have not thought about it but you may be able to use the one scale select for both MPGs. Using digital knobs lets you minimize the number of pins you need for the scale hence the mux4 components.

The Pi4b was marginal, sometimes requiring a slower servo thread but one guy I know says the Pi5 is flawless on real machines
I'd probably pair it with a mesa ethernet card. A Mesa 7i76eU has 5 axes, 16 outputs and 32 inputs but is extensible beyond that.
Linuxcnc supports 9 axes and 32 motors
Arduino is not useful for linuxcnc
There are several GUIs that support lathes but its always best to start with axis until you get everything functional.
Of course we are friendly!
You can mess with everything!
Check the docs as they list the GUI's available but you can write your own. Some support portrait mode.
I checked the other day, there's is over 1800 pages of docs but I always refer to the online docs.
There are no limits to motor size and it will control Ethercat and analog servo motors not just step and direction.
Linuxcnc is far more flexible than Centroid and is complete as opposed to Centroid where additional upgrades are required.
But it may require more effort from you  because there are probably more decisions you need to make becsause of LinuxCNC's flexibility

Re Youtube not sure on Lathe specific videos but I have a channel which is trying to produce tutorial type material.
This one is designed to be a general introduction describing the various pathways through Linuxcnc 

I'm currently working through a series of videos building a control panel from scratch using a parallel port (3rd one to be released tonight) with a couple more planned. Once fully functional, my plan was to replace the parallel port with other controller options. Sounds like I need to include a lathe walkthrough too!



 

mesaus has one:

mesaus.com/product/7i76eu/

 and our EU dealers have more

We should have the next build lot done in about 4 weeks

Thank you I will give that a look
 

There is one on ebay right now for $200.
www.ebay.com/itm/227441166265

   I have a new build project coming up and I need a 7i76EU for the build. But as my luck
usually runs Mesa Electronics is sold out of them. Does anyone know when more 
are expected to be in stock?

There is also a good MPG example in the docs except in Mesa land, you don't use the encoder component
linuxcnc.org/docs/stable/html/examples/mpg.html
Not sure on the 7i97 but there are some dedicated MPG pins on the Mesa 7i76e (and for the 7i96 if you use the right bit file and give up some pins.

I should note that I have a HP EliteDesk 800 G1 that could never run Ethernet cards reliably
 for more than an hour or so UNTIL I upgraded the kernel to 7.x

It also requires:

disabling irq coalescing
isolcpus=3
and pinning the Ethernet IRQ to CPU 3

With these changes, I never get dropped packets even after months of uptime
with a PC used for compiling, youtube etc etc

So does that mean you are in business and have a PC for spare parts? Hope so!
If not, I might be able to work in another site visit but it would cost you some footage for a YouTube video... 
There is an email that gets me on my @MrRodW YouTube channel

I connected a second PC to test wether the PC or the mesa board is dropping the connection. The result is the second PC works well for well over 20 minutes without interruptions or errors. it seems as the disconnected link was caused by the original PC. 

Just completed a successful installation of LinuxCNC version 2.9.8 on a Pi 4 with 4 gig of RAM.

Thanks to forum user "NWE" for recommending the version to download, named below:
2026-01-21-raspios-lcnc-2.9.8-trixie-arm64.zip

After downloading and using balenaEtcher to flash a 256Gig micro SD card, it booted to a Debian 13 Trixie style desktop and opened a "boot wizard".  After creating an account, the wizard recommended loading updates.  There was trouble after that, the login dialog box wouldn't accept any userids/passwords.

After rebooting and choosing NOT to load s/w updates, everything worked fine.  

I'm using LinuxCNC to retrofit a 1990's vintage Intelitek ProLight 3000 CNC lathe.  The original lathe was controlled using proprietary h/w and PC-based s/w.  I acquired a Mesa 7i76EU board as recommended by Mesa Technical Support so the journey is underway.

I see that LinuxCNC has a Mesa board config tool so I'll use that.

Any advice or coaching for me as an absolute LinuxCNC newbie is much appreciated.

 

Rykagon wrote:

Hello All,

- which Linux distro to load on the Pi 4.

 

Sounds like a fun project. 
Download the SD card  image at this page .
That should be a good start Pi4 + Mesa 7i76EU + TB6600. I've played a bit with the Pi, never used it in a retrofit, but I read people doing it regularly on this forum.

Hello All,

  I'm attempting to retrofit a 90's vintage Intelitek Prolight 3000 lathe.  This is a small slant bed CNC lathe marketed to high school and technical college programs, and originally controlled by proprietary electronics and a desktop PC.

The plan is to use LinuxCNC on a Raspberry Pi 4, mated with a Mesa 7i76EU board, along with TB6600 stepper drivers to control and X- and Z-axes as well as a stepper driven 8 position tool changer.  The spindle motor speed is analog controlled 0 - 10 volt signal input.

I have zero experience with most of this and would appreciate any coaching on:

- which Linux distro to load on the Pi 4.
- any resources for configurations, etc.
- any other stuff I don't even know that I don't know.

Thanks in advance!
 

Hi everyone,
I'm working on a KEGEMA-branded CNC router (1300x2500mm working area) that currently runs on a RichAuto DSP A11 handheld controller. I'd like to bypass the handle and control the machine directly from a PC (jog, home, run G-code, start/pause) — similar to what was done in this thread:
forum.linuxcnc.org/30-cnc-machines/35371...troller-richauto-a11
I've read that thread carefully and it's been very helpful, but my setup differs in one important way: my machine uses AC servo motors, not steppers.
Machine specs
Working size: 1300x2500x200mm
Spindle: 6kw HQD air-cooled
Spindle inverter/VFD: 7.5kw Fuling (brand: Folinn on the unit itself)
Axis motors: Leadshine 750W AC servo motors + matching Leadshine AC servo drivers (model marking "L7", 750W, one per axis: X, Y1, Y2, Z — Y1/Y2 appear to be a dual-motor gantry setup)
Reducer: Shimpo (Japan)
Control: RichAuto DSP A11 handheld controller
What I've already confirmed
Inside the control cabinet, the A11's interface board has clearly labeled screw terminals (not just a blind 50-pin harness like in the thread above):
INPUT SIGNAL row: X1 (XH/X-home), X2 (YH/Y-home), X3 (ZH/Z-home), X4 (TS/tool setter), X5-X8 spare, 24V/GND/SHIELD
OUTPUT row: Y5-Y8 + GND (relay outputs — dust collector, water pump, etc.)
Separate 4-pin terminal blocks per axis labeled X_AXIS, Y_AXIS, Z_AXIS, C_AXIS, each with 5V / PULSE / DIR / SHIELD
Each axis terminal block has its own cable running directly to its Leadshine servo driver's CN1 connector
Since these are screw terminals (not a sealed connector), my plan is to add a second wire in parallel at each terminal (tap-off) rather than disturb the existing A11 wiring, so the A11 handle stays functional as a fallback.
What I'm unsure about / looking for help on
Pulse/Dir signal type from Leadshine 750W AC servo drivers (L7 series) — are these standard 5V single-ended step/dir inputs, or differential (like the RS422 signals in the referenced thread)? Trying to confirm from the datasheet before wiring anything.
Recommended motion controller for a 4-axis (X, Y1, Y2 as dual Y, Z) AC servo setup — Mesa 7i96 vs 7i76e vs something else? Do I need differential drivers (like the AM26L31CN used in the referenced thread) between the A11 board and the controller card?
Dual Y-axis (gantry) handling — should Y1 and Y2 be wired as one LinuxCNC axis with a single driver output, or does anyone have experience keeping them as two synced axes?
Spindle speed control — my board also has S0-S3 speed-select terminals (7-speed selection, not analog 0-10V). Anyone dealt with converting this to continuous VFD speed control from LinuxCNC/Mach, or is it easier to just leave spindle speed control on the VFD's own panel?
Any gotchas specific to RichAuto A11 + AC servo (vs. stepper) retrofits that I should know before starting?
Happy to share more photos of the interface board and servo drivers if useful. Any pointers, schematics, or "here's what worked/didn't work for me" experiences would be hugely appreciated.
Thanks in advance!