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I'm not sure yet. I installed Debian Trixie on an i7 the other day. It uses 6.12.6. I installed Linuxcnc on it from the Debian repositories (which also installs linux-image-rt-arm64 as a dependency) and everything worked correctly.It might just be an ARM problem,

Hey, everyone.I'm doing a linuxcnc conversion on a ShopSabre 23 machine. Just got a 7i96 board in the mail and have been setting it up on my desk. It's been good so far, got the relays and endstops working. Unfortunately the spindle is giving me some trouble. We have an 18k rpm spindle driven by Mitsubishi A800 VFD which accepts 5-10 analog speed control.

I was under the impression that I would be able to convert PWM into analog voltage with this card and that's how I set it up in the Pncconf 18000 rpm at 5v, but the rpm readout in qtdragon only goes up to 500 for some reason. The spindle setup looks like another stepper config and I'm confused about the scale. I've read pretty much every spindle related post here which lead me to more confusion since everybody has different hardware.I haven't flashed any firmware on the card, just working with the stock one that it came with.I have a PWM to analog converter board

Here is the VFD manual   you can find the speed control on page 115

Can somebody please steer me into the right direction?I will include my ini an hal files just in case.

Later versions of Debian (we use debian 12 bookworm) requires careful optimisation on 2 core machines. I would suggest a 4 core Celeron, 4gb RAM, any sized SSD

Thanks Rod,

I gave this a try because I was excited to read that "This release includes realtime support (PREEMPT_RT), a feature that has been in the works for 20 years." So is there a bug in the PREEMPT_RT support in the 6.12 kernel, or is it simply not implemented the way LinuxCNC has come to expect? Obviously LinuxCNC needs to support a working standard.

Yes. you could try sudo apt install linux-image-rt-arm64

Yes the kernel needs to be specifically built to support preempt_rt even in kernel 6.12
It seems that on the Pi a default 6.12 RT kernel build is not recognised by linuxcnc unless the kernel has additional settings that are provided in the patch. This may end up being fixed by the kernel developers in later versions

This may not be relevant to you but building a custom image that includes Linuxcnc is not trivial and requires building a kernel from source so it needs to be a RT kernel.


 

I'm trying to do this with an Rpi 4 and I'm seeing the same thing. I can find the PID of latency-histogr. Then run chrt -p PID which reports that current scheduling policy as SCHED_OTHER. Then run chrt -f -p PID which does change the scheduling policy to SCHED_FIFO.

But all I did (hoped was necessary) was to update the kernel. sudo rpi-update next, thne reboot. Must one actually build the kernel with a patch? That seems odd if the kernel offers full RT support.

Oh, it's part of the Kernel files isn't it. Ugh.

Roy,

I've updated the kernel to 6.12.8 on an Rpi 4, and I'm seeing pretty much the same behavior. However, I'm not finding the file you patched anywhere on the system? sudo find / -print | grep ksysfs finds nothing.

Thanks,

Gene

What I am trying to do: in a 1" x 1" square workpiece, cut a .68" ID hole starting at (.16",.16").  The mill is .125" nminal diameter.  It is actually .122".

The gCode I tried, producing a hole that is too small:

g1 x.16 y.16 f25
g1 z0 f25
g2 i.-34

Update

Motherboard won’t even post to bios.

Cf card was empty.

I just ordered a 7i96s

If I have to build a new system I’m gonna get a better computer.

Lcvette,

Thanks for the help.

I'm unsure why the file names on the forms now have the 2025-01-09 attached. It must have been added when I uploaded them. They match what I have in the ini file except for the postgui file name error. I thought I had changed that one. I have made the suggested changes and still can't launch Probe Basic. getting the error "Can't execute DISPLAY program probe_basic  "





 

Anything above Core2Duo should do, 8GB of RAM (works OK with 4GB) and 32GB of disk space (HDD or SSD or NVME).
See here for some more info:
forum.linuxcnc.org/18-computer/38838-har...ency-tests-used-pc-s
And see here for some laptops that work, just do not bet on it as you might find the same model that does not work, i know i did
forum.linuxcnc.org/18-computer/54369-use...ernet-boards?start=0

Is there any requirement for building a Linuxcnc computer.

hd size
ram size

thanks john
 

I/O 34 and 38 are  still available  as GPIO
(1 differential input and one differential output on the 7I74)
There might be room for some simple feature on those pins
(say PWM for output  or encoder 'A' pin for input)