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Switch spindle to c axis 360 degre

Posted: Thu Oct 07, 2021 1:03 pm
by OptionSR
Hello,
i am new to the world of cnc in canada.
I am looking for the complete procedure to change the spindel to c axis?
should we put a brake on the vfd?
what else to change?
1 kw motor,
cnc lathe, acorn controler version cnc12 v4.64
thank you

Re: Switch spindle to c axis 360 degre

Posted: Thu Oct 07, 2021 4:12 pm
by suntravel
For making a spindle to a C-axis, you need to drive it with an servo and encoder on the spindel if its not slipless 1:1 driven with the servo.

A mechanical brake makes only sense to hold a position firmer than the servo could do for milling with driven tools ect.

But not sure if Acorn can do this.

Regards

Uwe

Re: Switch spindle to c axis 360 degre

Posted: Fri Oct 08, 2021 9:39 am
by centroidsupport
To run the spindle as a C axis, you'll need to drive it with one of the step and direction outputs on the Acorn. I am not aware of any VFD's that accept step and direction.

Re: Switch spindle to c axis 360 degre

Posted: Sat Oct 09, 2021 12:57 pm
by Bender_Is_Great
I've been wondering about this also. I was looking at getting one of Clearpaths SDHP Integral hp motors for use as a spindle motor and for C axis positioning. https://teknic.com/model-info/CPM-SDHP- ... =110VAC1ph

How would we configure CNC12/Acorns step and direction output to act as a spindle and a C axis? Is that possible? Would we need to run a VFD with an a/c motor for spindle speed, and a separate servo for positioning instead?

Re: Switch spindle to c axis 360 degre

Posted: Sat Oct 09, 2021 8:26 pm
by Gary Campbell
It won't work with a ClearPath motor. You have to choose between step and direction (position) with the "SD" series or rotation via speed control (velocity) with the MV series. This is the way it is with most any motor.

Some have had varying degrees of success using DYN servos, but was not impressed with the results.

That said, I have had good luck doing both with a soon to be listed for public sale Leadshine servo. At Keith's request, I will be doing a bench test showing the process and if we are nice, maybe Centroid will generate an approved schematic.

Should happen in the next couple weeks, as almost all the parts are here.

Re: Switch spindle to c axis 360 degre

Posted: Tue Oct 12, 2021 5:35 pm
by OptionSR
thanks everyone, Gary can you update this post when you get new info ?
have a great day.
Alain