Hardinge Lathe CNC Retrofit/Conversion

[m_c]

There will need to be some form of encoder signal to the controller from the spindle.

[glbreil]

Yes that is what I thought, I believe the Fanuc drive must put out the signal through the Speed arrival output, but I don't see anywhere on the Hickory controller to accept it. Fanuc Spindle IO.pdf I may need to contact Centroid.

Thanks Gary

[m_c]

There is most likely an independent spindle encoder, which will connect directly to the controller.

If you look at the Hickory wiring diagram, it makes mention of a spindle encoder cable (DB9 connector at lower left of the hickory board)

[glbreil]

The Fanuc spindle encoder connects directly back to the drive through the CN2 cable mentioned on the Centroid/Fanuc Spindle I/O. If it requires a separate encoder to get feedback to the controller, it might be easier to just use a simple VFD rather than the Fanuc drive.

[Muzzer]

If you don't plan to use ethercat, it looks to me as if the Acornsix would do the closed loop control of both the axes and the spindle. It's less expensive than the Hickory and that also applies to the associated software.upgrades.

If you prefer to use the motor encoders for axis position feedback, rather than use linear encoders, you can usually take an "encoder output" from the servo driver back to the system controller. This encoder signal can be a different resolution to the actual motor encoder itself - you can set the resolution in the driver setup

Most spindle VFDs are intended for speed control, rather than position control (which would be a servo's job) and they tend to be sensorless. This means you need to provide your own position encoder unless you have a fairly exotic VFD with position sensing. Furthermore, for cnc control, the spindle encoder needs to be directly geared to the spindle 1:1, which isn't usually the case if the encoder is mounted in spindle motor - unless the motor is part of the spindle itself.

[glbreil]

Hello I got all of the control wiring figured out on the Fanuc A06B-6055-H106 window drive, but as soon as I apply voyage to the 0-10 volt input it gives an alarm 02 without ever making a sound or trying to start the motor. I also noticed that when just rolling the motor by hand the load meter would go all the way to the top and if you stop it in the right place will stay there.

I read something that sounds like that can be caused by a bad motor feed back sensor.

I guess any thoughts, and I guess my real question is there any reason I can’t just drive the Fanuc 7.5HP AC spindle drive motor with a cheap VFD?

It does have a separate spindle encoder as Muzzer mentioned earlier.

Thanks Gary