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Compact 8 lathe servo spindle with acorn?

Posted: Wed Sep 13, 2017 1:53 pm
by frijoli
Two basic questions.
Is it feasible to use a servo motor from the 0-10v signal and a voltage to pulse converter?
Is it possible to use one of the axis to control the spindle?
Thanks in advance.

Clay
Ps. I already Ave a spare servo, but do not have a 3 phase spindle motor or VFD available.

Re: Compact 8 lathe servo spindle with acorn?

Posted: Wed Sep 13, 2017 2:36 pm
by DICKEYBIRD
Perhaps a servo control will do what you want? There are many on the market of course, but AMC is one that comes to mind that's available reasonably priced on ebay if you're working to a budget. I have an AMC BE25A20AC which has a built-in power supply and will work with several motor types. Acorn's spindle output should control it. I'm not sure on reversing capabilities since I think Acorn is +0-10V and YOU may have to build a simple polarity reversal relay circuit for spindle reversing. All this is just a free suggestion; take it for what it's worth. :D

Re: Compact 8 lathe servo spindle with acorn?

Posted: Thu Sep 14, 2017 3:31 pm
by martyscncgarage
frijoli wrote: Wed Sep 13, 2017 1:53 pm Two basic questions.
Is it feasible to use a servo motor from the 0-10v signal and a voltage to pulse converter?
Is it possible to use one of the axis to control the spindle?
Thanks in advance.

Clay
Ps. I already Ave a spare servo, but do not have a 3 phase spindle motor or VFD available.
Can you explain what you are trying to do? Are you just wanting to drive a DC motor on your spindle?
Can you tell us the specs of the DC motor? Horsepower and Voltage? Is it like the Emco CNC Compact 5's DC motor?

Re: Compact 8 lathe servo spindle with acorn?

Posted: Thu Sep 14, 2017 7:18 pm
by frijoli
"Can you explain what you are trying to do? Are you just wanting to drive a DC motor on your spindle?
Can you tell us the specs of the DC motor? Horsepower and Voltage? Is it like the Emco CNC Compact 5's DC motor?"

Hi Marty,
The motor on the "8" is a single phase AC. About 1/2HP
I want a variable speed spindle motor controlled by the Acorn. I have an existing servo motor that I would like to use because I have it. I was wondering if it was possible to drive the servo using the 0-10v output using a analog to pulse converter and the encoder input back to the Acorn.

If that isn't reasonable, can you control the spindle via one of the 4 axis outputs?

Thanks for you assistance!

Re: Compact 8 lathe servo spindle with acorn?

Posted: Thu Sep 14, 2017 8:59 pm
by martyscncgarage
A servo motor is a DC brush motor. You could run it with a KB Electronics DC controller.
See my Dyna DM2400. It runs a DC brush motor and a KB Electronics motor control fitted with the SI-5 signal isolator. What you need to know is the terminal voltage of your motor and it's HP so you can size the KB Electronics DC control properly. It gets more complicated if you want to reverse the motor but doable. Different KB controller.

Re: Compact 8 lathe servo spindle with acorn?

Posted: Fri Sep 15, 2017 9:14 pm
by frijoli
Thanks Marty,
I hadn't considered running it a DC motor. Interesting.
I was trying to avoid buying a motor control, but that's not a bad idea.

I am assuming this means you cannot control the spindle via one of the axis in the Acorn.

Re: Compact 8 lathe servo spindle with acorn?

Posted: Fri Sep 15, 2017 9:40 pm
by martyscncgarage
frijoli wrote: Fri Sep 15, 2017 9:14 pm Thanks Marty,
I hadn't considered running it a DC motor. Interesting.
I was trying to avoid buying a motor control, but that's not a bad idea.

I am assuming this means you cannot control the spindle via one of the axis in the Acorn.
Technically, I suppose you could use an axis to control it, provided the servo amplifier too step and direction inputs....but not so sure you could use conventional M3/M5 and S words to control the spindle. Let's see what Centroid has to say about it....

Marty

Re: Compact 8 lathe servo spindle with acorn?

Posted: Fri Sep 15, 2017 10:06 pm
by martyscncgarage
Is there a reason why you don't install a 3 phase motor and VFD? Could you get a 1 or 2 hp 3 phase motor on it? That might be simpler than doing the DC motor. Certainly easier to reverse and control with Acorn

Re: Compact 8 lathe servo spindle with acorn?

Posted: Sat Sep 16, 2017 10:22 pm
by frijoli
martyscncgarage wrote: Fri Sep 15, 2017 10:06 pm Is there a reason why you don't install a 3 phase motor and VFD? Could you get a 1 or 2 hp 3 phase motor on it? That might be simpler than doing the DC motor. Certainly easier to reverse and control with Acorn
The main reason, and really the only good reason, was that I have the servo which has an encoder, and wanted to know if it was feasible before I bought anything I didn't need.
I don't have a 3 phase motor, nor a VFD, nor an encoder on hand.
I'm not worried about the money, but I didn't want to waste it unnecessarily. Why spend 400-500 dollars if you don't need to right?

Thanks Marty!

Respectfully,
Clay
PS. I probably should have mentioned my Servo will take step and direction.

Re: Compact 8 lathe servo spindle with acorn?

Posted: Sat Sep 23, 2017 6:51 pm
by martyscncgarage
Clay, what servo motor do you have that takes step and direction? Is it a Clearpath SDSK?
Or is it a motor and servo drive that takes step and direction?
Marty