Plasma cutter.


Today the first test run

First pieces jpeg.
Start went well, then the x axis broke down, restart arduino, then the y axis broke down.
1 of 2 attempts no problem
Laptop and arduino stood three meters away from the plasma cutter.
Anyone have an idea what I can do about this?
Arduino in an iron box?
Shielded cables for motors? (Now used ordinary UTP cable)
Kind regards Marc A



You are my hero!!!

Are you sure the issue is the plasma? Just to be sure can you run a long file without the plasma on then it only messes up with the plasma on? Using an LCD controller or a laptop?

A few other things it could be but never know.

Someone else just grounded all his metal tubes in the forums, this might help. The wires are shielded, the connections on the solder less mount’s aren’t ideal in this case, maybe solder them up, a metal box for the arduino couldn’t hurt.

Wow! Speechless…


We use a laptop, no lcd at the moment.
We will ground the tubes, put the arduino in a metal box and get some shielded cables for the motors.
We have drawn your logo four times with a pencil connected to the cnc without any problems.
We have run each cut without the plasma cutter turned on and we never had any problems.
When we ran the cuts with the plasma cutter on however sometimes one of the axis stopped working, exept for the Z-axis, this one never failed.
Apparently, only the activated axis fails when the plasma ignites.
As soon as we rebooted the arduino everything worked again.

Before I forget, thanks for sharing your project!

That’s so cool! Wish I had a big fireproof place to build one of these. Not going to happen, but very neat to see it can be done!

Figuring out the grounding and shielded cables would be the best place to start if it works w/o the plasma cutter turned on.

Aside from that issue, your cuts look pretty good for initial testing. What are you using to trigger the torch on and off?

Very cool!!

I have some picture of how I grounded mine in this post. I did this more for static electricity.

The white cables are shielded and you would need to bond the shielding to the ground. Also for your setup, connect it to a electrical system ground, like through grounded power supply.


The wires I include are shielded you just need to ground them.

Looks like this thread is going to get very popular!


Setup > Laser etc >

Cut Start
M106 Close relais on D9 (can be switched with D10 on the firmware)
g4 s0.7 Wait 1 sec before moving

Cut Stop
M107 Open relais on D9 (can be switched with D10 on the firmware)

Use a 12V dc relais on D9 on the MEGA. to switch torch.

Kind regards.

Cool, definitely makes me want estlcam more now that I know it is easy to control the torch with a relay.

You win! Congrats are in order, you beat me to it.

I think you have all covered the possible noise generated by the plasma.
Plasma tends to draw a goodly amount of current, could it be causing some sort of brownout situation?

Cool. How do you ensure the D9 output isn’t PWMing? Is M106 enough, or do you need to specify “M106 S255”?

For the flaky electronics, you could try adding filters to your power supply – ideally monitor the 12V line with a scope and then select capacitors to filter out the frequencies you are seeing. Or just take a guess; put at least one nice big electrolytic cap across your 12V/ground rails in case you are getting brownouts.

What brand of plasma cutter are you using. I just finished building a cnc plasma table. I tried using a older Esab but the HF start jammed up my electronics. I know allot of the
Chinese plasmas put out some nasty frequency’s as well.

Photo in Attach

Do you have any more details on how to hook up the relay, and the wiring for swapping out the torch? I’m brand new to plasma torches, and haven’t really used relays very much.


Start here,

I used A solid state relais.

Kind regards Marc

So for you plasma guys out there… what would be the “ideal” plasma cutter for using for cnc? I cancelled my order on my unit I ordered since it was High Frequency start, and I’m trying to find a unit that is a pilot arc start, to be easier on the electrical trouble shooting. The problem I’m having now, is finding something affordable, that is pilot arc. The more and more I thought about it, the chinese plasma cutters scare me.

So really what I’m asking, is which torches has anyone found that is pilot arc? All the product descriptions around the internet are pretty vague on details… I’m trying to keep this semi affordable

Awesome video of the cutting by the way

Want one! I thought the pantographic plasma cutter setups were awesome, but CNC plasma cutting is a goal worth working for.