how to connect a servo for spindle

[rk9268vc]

Hello,

I am comparing a few different options for controllers.
I see that the acorn has a 0-10vdc control for spindle and an encoder input.
How would I control a servo spindle with this that can be stopped and reversed? Like if I wanted to do rigid tapping.
The servo drive is a yaskawa SGDH-50AE
The servo is a Yaskawa SGMGH-44ACA61 if that helps

Thanks

[cncsnw]

If you were to build a closed-loop servo control using either an Allin1DC unit or an Oak, then you could configure the analog output for bipolar (+/-10V) speed and direction control.

With an Acorn, you will need extra circuitry to selectively invert the analog signal. There was some discussion in another thread about a proposed (or current?) CNC4PC product to do that.

You could also review the Sigma II manual to see if there is any provision for using a sequence input to trigger motor reversal.

[rk9268vc]

I find it odd that the 'pro' version of the acorn software explicitly supports ridged tapping, yet the board doesnt have an obvious way to reverse the spindle.

I could use two relays to swap the polarity (swap the GND and 0-10vdc wires), but I dont see an obvious way to have it auto do that with CAM.
I will be using fusion for CAM btw.

[cncsnw]

The Acorn does have an obvious way to reverse the spindle: it turns off the run-forward relay and turns on the run-reverse relay. This works with 99% of the variable-frequency spindle drives you are likely to encounter in the field.

What you are proposing with relays will probably work. As I understand it, it requires that the analog input on your servo drive be "differential", with neither leg (CN1-5 or CN1-6) tied to chassis ground. That is because I am fairly sure that the analog common on the Acorn is tied to chassis ground.

Your relay would be controlled by the PLC, in response to normal spindle forward/reverse control. It would not require anything different or special from the CAM software or G codes.

[briuz]

About a week ago I configured an Acorn to run a spindle using a servo. (The servo was a TECO TSTA series.) This servo had to be configured in speed mode. There is a 0-10 vdc input, input for reverse, etc. So, with the servo in speed mode it works fine. (Even all speeds are within 10 RPM of the setting, too.) The servo also has a ouputs for the encoder so I wired them to the Acorn as well. I don't know if your servo has this capability but the TECO servo I have is from around 2013 or so....so maybe it does. You'll have to check your manual.

[cncsnw]

Quickly scanning through the Sigma II user manual, it looks likely that you can do what you need, by:

• Configuring inputs for "contact input speed control"

• Setting Pn000.1 = 4

• Leaving /SPD-A and /SPD-B inputs open/off/0

• Controlling direction with a /SPD-D input.