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Hi everyone,

I’ve read through a lot of forum threads and would like a sanity-check before I start converting a large manual lathe (≈ 7 m between centres, three controlled axes: X, Z and spindle) to CNC.

Outline: IPC running LinuxCNC  →  Beckhoff EK1100 EtherCAT coupler.

1) Spindle (big induction motor that must stay)
   • Ideal: EtherCAT-ready VFD.  
   • Fallback: keep the old VFD and drive it with ±10 V from an EL413x analogue-out.  
   • Right now I only need the spindle to reach the commanded RPM.  
     Do I really need extra feedback (index pulse or full encoder), or is open-loop ±10 V enough for a first-cut retrofit?
     I can add an EL5101 / EL5042 later if it saves headaches.

2) Linear axes (X, Z)
   • Replace the old drives with EtherCAT servo drives; current & velocity stay inside the drives, LinuxCNC closes the position loop.  
   • New linear scales will be fitted. Where should their signals go?
       – straight into the servo drives, or  
       – through a Beckhoff encoder terminal (EL50xx) so LinuxCNC sees raw position, or maybe both.  
   • I’m after whatever gives the most reliable closed loop without over-complicating wiring.

3) Limit switches
   • Where do people usually land these in an EtherCAT setup?  
       – dedicated digital-input terminal (EL1004 / EL1008),  
       – directly into the drive I/O and pass the state via PDOs,  
       – or something else?

4) Still unsure about
   • Pitfalls when driving an older VFD from a Beckhoff analogue-out terminal.  
   • Best practice for scale feedback on a long machine: drive only, EL50xx only, or split to both.  
   • EtherCAT servo brands that work well for retrofits (good low-speed torque, reasonable cost, easy integration).  
   • Cleanest way to wire limit switches in an EtherCAT chain.

Thanks a lot for reading. I’m grateful for any advice, success stories or warnings you can share!

Kind regards,
vformi

Hello, we have a machine with a rotary axis, in some corners the cutter does not reach the corner completely and makes a rapid movement on the rotary axis. I tried to reduce the error with G64 but lowering the P value makes it worse.

Machine is running analog servos, old yellow cap fanuc.

The error is consistent int the same place.
Attached a pic.

Thanks
 

Things I noticed in stable version .


Would it be possible to add a confirmation dialog box prompting the user before initiating another homing cycle .

When I run the program and want to pause it midway through the G-code execution to clean the machine from chips, it doesn't allow me to manually move the axis.
I believe the program should allow pausing, during which I should be able to manually move or return the axis. When I choose to resume the program, the machine should automatically return to the position it was in before the pause and continue execution from that point.
Also, if I stop the spindle and start it again, the speed is much lower than before.

When you're in the G-code editor, it's possible to start the program execution, but if you exit the editor, the program stops .

1. download Ubuntu 10.04 with LinuxCNC from here
www.linuxcnc.org/iso/ubuntu-10.04-linuxcnc3-i386.iso
2. write it to USB drive, google howto with Rufus
3. boot the PC from that USB
4. click on "try Ubuntu"
5. open a file folder, on the left find the internal HDD and click on it, on the right find /home/whatever_user_name_was_on_it/EMC2/configs
6. copy that config folder to another USB drive or a phone or external HDD
7. open that configs folder on the internal HDD, open the config inside, right click on the file with .ini extension, choose "open with" and type emc2, press enter
8. does the machine run?
If all is OK, remove the other USB or phone or external HDD, and proceed to install Ubuntu.
After restarting use the other USB or phone or external HDD and copy the configs folder where it was, start it as in point 7, or use the CNC menu and click on "create desktop shortcut" after you choose your config in the config picker.

Alright, it seems to running ok now and the tuning worked exactly how you described.
FF1 is just right at 1 and the p ended up about 5x what it was before.
Thank you

Try another network cable, kinked or nicked or stepped on cables can cause issues. Also some cheap cables will cause a lot of headaches, sometimes even not so cheap ones as i had a brand new never used cable that would absolutely not connect to Mesa. I did cut it into many tiny pieces Over 30 of the same brand worked fine.

Pinned for easy finding.
Thank you.