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Hello, I have been doing some research and I want to understand better the difference on these systems, for instance these setups in the videos use Raspberry pi 4 and Ethercat so he can directly talk to the servos and no mesa card is needed, I understand Ethercat makes wiring much more simple and the cabinet has less parts,also on some servos is possible to do homing directly, some cons seem that is  harder to implement because there is less info out there and hardware is possibly more expensive usually, but my question is to know if it is as powerful as a mesa card setup on the max step rate side of things? any other toughts I may be missing?

 


Thanks!
 

royka wrote:

The SPI driver has nothing to do with Armbian, it's in the kernel, it seems to be a known issue with the default (example) driver. Unless their is a proper SPI driver for the rk3399 it won't be different on that sbc. AFAIK there's only made a realtime driver for the RPI.
Unfortunately I don't have a spi board to test with, perhaps it helps to pin the irq of spi to an isolated core?

I've seen that there has been a rt patch for one board for a quite old kernel, I can try to find that one and if I'm able to apply that on the newer kernel.
 

Is there really a real-time kernel version for the rk3399, like the one for Raspberry Pi? Because I haven't been able to find anything about it.Also, if you manage to find something useful with the older kernel, I’d really appreciate it if you could let me know. Thanks

Thank guys, I'm starting to get a few of the blanks filled in. I now have a few more questions:

I read this (quickly)... linuxcnc.org/docs/html/lathe/lathe-user.html
I also watched this video on G76 thread cutting...

Links to other applicable documentation or instructional videos (specific to LinuxCNC lathe operation are welcome.

Now the follow-up questions:
1)  I don't see a problem using the G76 method in the video above except, I'm a hobby guy so it can be months between thread cutting sessions so with my present memory I would pretty much have to watch that video to refamiliarize myself with the various parameters before I could setup for a thread cut. Is there any sort of thread cutting wizard like GUI thing associated with Axis that simply lets you select the thread type for example 3/8-16, starting here, and ending there that then figures out the arguments required for G76?

2) Presently I have a derivative of the Clough42 ELS on my lathe and it uses a Omron 600 pulse/rev quadrature encoder. Assuming I use a MESA 7i96s to get that quadrature encoder signal into LinuxCNC, will the 600 pulse/rev encoder be fine (ie. not overwhelm Linux with too many pulses if operating at say 2000RPM)?

3) Looks like I will need a one pulse per rev sensor on the spindle correct? The Omron encoder I'm using has a Z output, so I will use that I guess.

4) Regarding the 7i96S, eventually I would like to use one or possibly two MPG style encoders to replicate the hand wheels for X and Z, it seems like I will have enough unused pins on the 7i96S, not sure if those inputs can be used for the MPG inputs and what would be involved in decoding the MPG inputs, possibly some logic in the HAL file? 

5) Not sure if I should get a 7i73 for the MPG(s), prefer to keep the hardware to a minimum if I can get away without the 7i73, comments?

6) Regarding X-axis servo. I measured with a peak torque sensor the required torque to do an aggressive cut with a dull HSS tool and peak torque was only 0.5Nm so I'm leaning towards a fairly small servo in the 1Nm range. Do you think this is too small?

7) Last question where can I find appropriate install LinuxCNC install file? I want to see if I can get it running on my RaspberryPi

Much appreciated

 

Ich komm leider auch damit nicht weiter, bei usr/bin/env kommt Verzeichnis nicht gefunden, wenn ich das env wegmache kommt permission denied. 

Ich hab zwei System, richtig arbeiten tut LinuxCNC 2.81, auf einem Raspberry Pi zum Testen hab ich auch 2.93 auf einem zweiten RPI installiert, die Fehler oben kommen vom dem 2.93 System, auf 2.81 passiert garnichts, vermutlich wegen alter Python Version.

Kann es auch ein grundsätzliches Problem an der RPI Installation sein?

Danke
Grüsse
Steffen

Hi thanks,

I am trying to get a quote on the EL-8, which is a more expensive/new version but I have seen them work on LinuxCNC through a Raspberry Pi.



I am a little scared to set these up though as there is not much info on doing this from what I've seen. As I also don't have much experience here especially when it comes to the setting up the drives addresses and communication.

slowpoke wrote:

Bunch of questions, Hopefully someone can fill in a few blanks as I formulate a plan for the lathe.

I'm using Axis for my mill and I'm completely happy with it. I'm now considering using LinuxCNC for my lathe. I definitely want to maintain manual operation capability.

Presently I have a derivative of the Clough42 ELS with feedback from the spindle and a stepper driving the leadscrew for threading. I like the simplicity of selecting various thread pitches metric and SAE electronically.
1) I don't suppose LinuxCNC has this "ELS" capability?

2) I also have DRO scales. Assuming I will use a MESA board, is it possible to connect the scales to the MESA board and use LinuxCNC as a glorified DRO without actually driving any steppers/servos?

3) Assuming for the moment I can use LinuxCNC simply as a DRO, what MESA board(s) would be a good fit for say max 3 encoder inputs and possibly up to 3 steppers later?

 I have a RaspberryPi of some sort and I might try using it for the LinuxCNC for both space and $.

4) What RaspberryPI's are likely to have acceptable latency and what versions should I avoid?

 I find the Axis GUI a good fit for my needs on the mill, what GUI is a good fit for lathe control?

Much appreciated.

 

I won't comment on GUI choice(s) here - those are personal preferences.  Regarding your other questions:

• Yes, LCNC has "ELS" capability.  Not in a turn-key configuration, but there's no reason you can't set LCNC up to act like your ELS.  All the elements are present: spindle encoder + Z-axis positioning motor + configurable logic.
• Yes.  And LCNC already has a "DRO" mode.  See  linuxcnc.org/docs/devel/html/gui/mdro.html
• You can read my long-winded post here:  forum.linuxcnc.org/27-driver-boards/5160...i-buy?start=0#292576
  • I'm not an expert, but I think the absolute cheapest Mesa combination to get an FPGA card (required) and 3 axis/spindle encoder inputs & step/dir outputs is a 7i92 (any variant) and a 7i85s.  You'd still need something else for IO, but that depends on your particular setup.
  • If your IO needs are moderate, a 7i96s and 7i85s would get you the IO and keep packaging to two (vs three) boards.
• Based on very little personal experience, Rpi's usually have decent to very good latency and potentially not-so-good user-interface response.  i.e. 'laggy' if using a power-hungry GUI.  If you are using Mesa hardware you don't have to worry about latency with an Rpi. 
  • I've got an Rpi5 and while I'm not using it (right now), it was just fine when I tested it with LCNC and Probe Basic (no interface lag).
• Lathe GUI - any GUI is fine except Axis.
  

Bunch of questions, Hopefully someone can fill in a few blanks as I formulate a plan for the lathe.

I'm using Axis for my mill and I'm completely happy with it. I'm now considering using LinuxCNC for my lathe. I definitely want to maintain manual operation capability.

Presently I have a derivative of the Clough42 ELS with feedback from the spindle and a stepper driving the leadscrew for threading. I like the simplicity of selecting various thread pitches metric and SAE electronically.
1) I don't suppose LinuxCNC has this "ELS" capability?

2) I also have DRO scales. Assuming I will use a MESA board, is it possible to connect the scales to the MESA board and use LinuxCNC as a glorified DRO without actually driving any steppers/servos?

3) Assuming for the moment I can use LinuxCNC simply as a DRO, what MESA board(s) would be a good fit for say max 3 encoder inputs and possibly up to 3 steppers later?

 I have a RaspberryPi of some sort and I might try using it for the LinuxCNC for both space and $.

4) What RaspberryPI's are likely to have acceptable latency and what versions should I avoid?

 I find the Axis GUI a good fit for my needs on the mill, what GUI is a good fit for lathe control?

Much appreciated.
 

Hello!!
I have implemented mesa 7c81 on spartan 6. Raspberry pi is connected with my board (spartan 6) and we implement linuxcnc on that board, everything works good here but while we run some big files after some time it shows error Unrecognized error -1 and my python scripts stop suddenly, even estop didn't work, file will run but my scripts, estop functionality stop working. Please Suggest any solution.

  Well first off welcome to the wonderful world of CNC. Firstly I recommend you read through the Linuxcnc manual, that will get you
going in the right direction. I don't have direct experience with using Raspberry Pi and Linuxcnc. I usually use the Dell Optiplex 9020
and MESA boards
however I recommend using 8 micro steps for most installs. That said you can run the full gamut from full step to 200 micro step
if your driver is rated to handle it.
  Next NO you don't have to run the exact same step setting on all drivers. You could use a belt
drive for one axis, for example a Y axis at say 100 micro steps and a ball screw axis, again for example X axis at say 8 micro step.
At that point you change your step counts in you ini. file accordingly or in your software wizard either Pncconf or Stepconf.
That way you should have accurate calibrated movements on your axis.
  You will have a lot of questions along the way everyone does, so don't get discouraged by it. I would recommend you run a few
simulated setups and play with the system to see how things work before you do your build.
  Lastly keep your build as simple as possible an gradually add in more complexity later if you so desire. It helps keep the
overwhelm from getting to you. I hope this helps and good luck with your CNC endeavors.

Hi,

I am trying to understand the Nema 23 closed loop CL57T driver. I have zero knowledge of CNC and stepper motors. I am learning with the objective of building my own CNC.

The manual for the driver: www.omc-stepperonline.com/download/CL57T_V4.0.pdf

The factory setting for the Microstep Switches are:

SW1 = ON, SW2 = OFF, SW3 = ON, SW4 = ON

This "Microstep 8" factory setting requires 1600 pulses per revolution. In my Python program, if I send in 1600 pulses the motor makes one revolution: I just observed that by eyes only.

When I set the switches to "Microstep 1": SW1 = ON, SW2 = ON, SW3 = ON, SW4 = ON

Then I send in 200 pulses and the motor makes one revolution: but it runs very fast compared to "Microstep 8".

I understand the relationship between switches and pulses. PLEASE HELP WITH THE QUESTIONS:

- When we use this motor and this driver with LinuxCNC, how do we set the Microstep Switches?

- Must all drivers' Microstep Switches be set the same?

Please pardon me if the questions are ignorant, all I have currently is LinuxCNC installed for Raspberry Pi 4B. I don't have any other relevant hardware, so I can't try anything yet. I am just trying to understand the basics.

I've attempted some settings, I have a video showing the speed at different pulses:



Thank you and best regards,

...behai.

Yes I had forgotten, its the RPI3 that uses USB --> Ethernet
I should know since I have run a Mesa Ethernet card from a RPI4.

 (I think some RPI4 --> Ethernet motion card users needed to increase
the servo thread period to 2 ms to get it to run reliably)

cornholio wrote:

I was always under the impression that up to version 3 the ethernet was on the USB bus and 4 and after were on the PCIe bus.

Me too !

I was always under the impression that up to version 3 the ethernet was on the USB bus and 4 and after were on the PCIe bus.

Hello to all.
I'm trying to build a custom GUI with pyqt5 for raspberryPi 5.
My linuxCNC version is 2.9.3, python version is 3.11.2.

I wanted to watch a input pin status whenever it changes.
I create a net in my hal file.
After I created this net, I can see the pin and its changing logic from hal show with axis GUI.
I examined the qtplasmac_sim_handler.py and tried to make connections as on it.

Here is my custom GUI's handler file
with this setup I cant see any changes. It only fires one time "Changed", and after that there is no information...

My guide qtplasmac_sim_handler.py did like I was...

What is my fault?

Basically the issue is that the RPI4 Ethernet interface is connected via USB
and USB is not suited for real time.

For a RPI4 I would use a SPI interfaced device, The RPI5 (or most PCs) are fine with Ethernet
LinuxCNC motion controllers because their Ethernet hardware are not USB devices.