Which Mesa cards for CNC lathe

I would be grateful if someone could help me with the choice of Mesa cards for my CNC lathe. I have experience with LinuxCNC but have never used any Mesa cards.

I have an slant bed 2 axis lathe (X 220mm * Z 220mm) and wish to make retrofit , to add AC servo motors (1500W) step/dir and YASKAWA A1000 inverter for main spindle.

I wish to add linear optical scale resolution 0.001mm only to X axis to have good accuracy and use Index signal for referencing / homing, this scale will be closed to LinuxCNC feedback, not to servo drive (dual feedback).

I need some I/O cards with enough inputs for front panel to use for MPG, feedrate, spindle override, chuck control and others.

Also a suggestion which type of PC for LinuxCNC to choose.

Thanks in advance!

tommylight wrote:

Nice machine.
I would try to use the existing motors and drives if at all possible, and those would most probably be +-10V analogue ones, in such case a mesa 5i25 or 6i25 or 7i92 coupled with a 7i77 would work nicely. Used that on a lot of retros.
For step/dir and scales maybe someone else has a better solution.

Thank you for your recommendation!

On that machine are the Fanuc AC servo motors A06B-0128-B077 with incremental encoder with serial output but I have no experience with Fanuc and want to install other AC servo motor & drive for ease of maintenance.

This lathe will be used only for ball-screw end machining and nothing others but need to be accurate for bearing mount with tight tolerance.

These are VERY FINE servo motors. I (Pico Systems) have a converter board that will create industry-compatible quadrature encoder plus index and commutation signals. So, you could use any modern servo amp with them, such as Servo Dynamics, AMC, Elmo, etc. These encoders give 65536 counts/revolution, but are of the incremental type. So, for our converter to produce commutation immediately after system startup, you need to provide a backup battery for the encoders.
Once the battery is connected, you will need to turn the motors by hand one turn so the encoder can sense its index position. I can advise on how to hook up the battery and charge circuit.

I also have a complete system for this type of motor - A PWM controller and PWM brushless servo amps, plus the Fanuc
converter. For a 2-axis lathe, that would be $250 for the 4-axis controller, $150 ea for servo amps and $150 each for
the Fanuc converters. So, a total of $850. The controller also has 16 digital inputs and place for 8 solid state relays for
digital output. We also have an option for analog speed control of a VFD for the spindle.

With enough free digital inputs you can also set up a jog pendant, which we have found really useful.

Jon

Mr. Jon I understand your recommendation but it seems too complex to me, i want to simplify it. The fewer components in a row the more stable the system is and lower latency time...

I think it would be a better solution to use the original Fanuc drivers that are already on the machine and connected to this motors.

This is type of Fanuc driver A06B-6079-H208 it is a two axis driver, do you have any solution on how to drive these drivers using LinuxCNC?

If there was no way to use a Fanuc driver + Fanuc motor that is already on machine now then I would simply put a new AC servo motors and drivers with a step dir signal.