Confused about using the THC with Plasma Cutters that don't have a CNC Port

I’ve been trying to find information about Voltage Dividers, breakout boards, etc. that would be aftermarket components to allow using the ArcDroid under THC control.

I’m not really clear on what is needed to make this happen. I do see there are some folks that are offering their version of voltage dividers even for those Plasma Cutters that have a CNC port built in. Appears to be related to developing voltage dividers because the onboard ones are sub-par.

Anyway, just have a revamped Votage divider surely can’t be all that’s needed.
Anyone care to provide some insight?

Thanks in advance,
Steven M

You can wire a voltage divider right off the + and - lugs on your plasma cutter. The arc voltage gets divided so the THC input circuit on your CNC can read and adjust torch height up or down as the arc voltage changes. Simple as that. The Arcdroid already has everything needed, you just need to send it a reduced version of the arc voltage, 50:1 is the recommend. Even up to 100:1 will work.

I did build and sell a bunch of adjustable voltage dividers with some extra protection and smoothing added into the circuit. With the current firmware updates, a basic voltage divider ( 2 resistors) may work. That’s usually what’s in most plasma cutters with CNC ports that have divided voltage but results may vary.

Thanks for the response!

I attempted to reach out to you via your website using its email address for contact.

I had asked you in the email when you expect the next batch to be available as you are currently sold out.

hmmm…I don’t see any emails, nothing in my spam folder. Sorry about that Steve. Now, I’m curious as to what may have happened to it.

Anyway, I got extra boards made while filling a large order for a company. I just have to order more components and I can make some more. I’ll try and get on that this week.
I’ll message you my email address.

I read somewhere else that you stated the connections from the voltage divider go into the Aux2 connections on the back of the ArcDroid. Also read that you may or do need a code from ArcDroid to enable the THC functionality.

So I my mind’s eye there’s connections to the (+) & (-) lugs of the Plasma cutter which go to the Voltage Divider, then out to the Aux2 on the ArcDroid. And nothing more hardware wise is needed. Only adjustments to Gain settings, etc.

A simple schematic would be useful. Not details of your PCB, just Plasma → VD → ArcDroid.


Correct. Andrew will send instructions with your unlock code, if they are still doing that. Just email ArcDroid with your serial number.

I email an instruction PDF when I mail out voltage dividers.
Should have info for you by Friday as to when the next batch will be available.

Another run of voltage dividers is underway, just waiting on parts. I’ll likely open up pre-orders later this week. I will let you know.

1 Like

I’ll be on the lookout for the notice.

Another batch of dividers are up for sale again. Shipping should start next week.

Placed my order late yesterday evening.