Rebuilding Plasma CNC

Hello, Friends!

I am working on getting an old Plasma CNC machine rebuilt.
We have removed the old control box, and we are beginning to look into repurposing the old motors.
We are looking into building a computer for the LinuxCNC environment, but I have a hard time determining the best way to connect Linux CNC to the motors on the old Plasma machine.
All of the motors (for the X, Y, and Z-axis) connect and splice into one connection.





In addition, this is the connection to the actual plasma.



I'm looking for opinions on the best way to connect a LinuxCNC computer to these two connections.

Thanks!

The first connector looks like a 20 pin ATX connector used on computer power supplies.
www.ebay.com.au/itm/ATX-20-Pin-Male-to-2...3:g:1qQAAOSwqNxcrpLW

The second looks like an audio 6 pin DIN connector which should be easy to find too.
au.element14.com/pro-signal/psg01567/cha...ni-din-ns/dp/1280671

If you need further help we'd need more info about the motors but I am assuming most likely they are stepper motors in the absence of more info.

That sounds right.

Would I need any hardware to connect to those? Any special boards, or would being able to connect to the computer be enough?

I think we need a lot more info about your motors, motor controllers and plasma cutter, if it has a voltage divider before advising.

If it is stepper motors, you can start with one or two parallel port breakout boards (depending on inputs required) and a Mesa THCAD to read torch voltage. But you would get higher performance from a Mesa 7i96 or 7i76e ethernet board.

Some photos of motors and controllers would help. Do some of those wires go to home and limit switches?

You may like to read this linuxcnc.org/docs/devel/html/plasma/plasma-cnc-primer.html

We have currently removed all of the electronic components.
The controller we had would not respond to any form of input.

These are the pictures that I have for the motors and limits.
Each axis has limits, as I understand it.







I have looked at some boards that have been suggested in the forums.
Most of the drawings I have seen have ATX ports for each axis/motor.
With all of the wiring for these motors going to one 20-pin ATX connections, would we need to rewire them to work with boards with the motors' connections separated?

Tommy, aren't the wires coming out of the side of the motor for the encoders?

In the meantime, have a look at Bob's plasma build forum.linuxcnc.org/plasma-laser/36667-bob-s-plasmac-build
as it shows a servo system with the required hardware. Hopefully you can repurpose what you have.

As for wiring, nothing will be plug and play. You will need to rewire but you should be able to retain the connectors you have now you know what they are.

I'll leave it to others better qualified to help with the servo motors.

You might want to look at this thread,

forum.linuxcnc.org/plasma-laser/36299-pl...ntrol-panel?start=40

I posted my wiring diagram for my new controller I built and some pictures of the finished controller.

tommylight wrote:

Those machines were advertised as using servo motors when they started selling, but i can not see encoders on them, so they just might be steppers.
To check, turn them by hand and see if you can feel small steps while turning.
And you you will have to rewire that connector.

Tom, I would be will to bet that the motor is the black part of the frame and the silver part is the cap for the encoder. They will most likely be DC servos. My old DC servos look similar.