How to convert a basic machine with Axis GUI to PlasmaC Gmoccapy GUI

Hi Phil,

I have the jumpers on the THCAD-10 on Unipolar and 1/32 as per documentation, we just checked the divider on our Hypertherm is set at 1:50 (factory default), the calibration sticker on the THCAD-10 gives 118.1KHz @ 0V and 961.2 KHz @ 10V. I have the Voltage Scale at 0.018900 and the Voltage offset at -3690, both variables obtained from the online calculator. The - sign on the Voltage offset made the Arc Voltage at idle 0V.

At your recommendations I have set the mode in the ini file to 1, to use the Arc OK signal from the plasma cutter. All pins seems to be working. We have done the probe test and set the parameters accordingly. What happens now is that when I do a single cut for testing, the torches probes, returns to the pierce height, and then the torch turns on for a split second, after which we get the following error : "valid arc lost program is paused". What is happening here ? It seems a bit strange, the arc didn't even have time to get going ?

Cheers, Peter

Hi Phil,

I got the plasma cutter cutting in mode 0, it turned out that both the Voltage Scale and Offset needed a - sign. I will have a play with different material thicknesses this afternoon. But there are a few happy faces around here !

This still leaves the question what happens when I use mode 1 and get the valid arc lost error. Now that I am cutting (in mode 0), I see the ARC OK LED on the GUI come on, and the led on the breakout board lights up as well, which indicates to me that it is working. I will open HAL show and check to be sure.

Cheers, Peter

CFE wrote:

Hi Phil,

This still leaves the question what happens when I use mode 1 and get the valid arc lost error. Now that I am cutting (in mode 0), I see the ARC OK LED on the GUI come on, and the led on the breakout board lights up as well, which indicates to me that it is working. I will open HAL show and check to be sure.

Cheers, Peter

This is not a question that needs answering because you should not be using mode 1 if your machine has an ArcOK signal available. I really get frustrated with people who think that the synthesised arcOK can be used to save them some work then wonder why they have problems getting their machine to work. Synthesised ArcOK should only be used if your plasma machine does not have its own arcOK signal.

Hi gents

I thought I made clear that we do have an ARC OK signal available from the plasma cutter, and I watched all the pins connected to it in HAL show and they all work. But when I use mode 1 then I get "valid arc error lost", don't know why. In mode 0 the machine works.

This is NOT about saving us work, we spend countless hours digging through documentation and the forum to piece together a working machine. And we do appreciate all the help, but some things are baffling, especially when following all the documentation and instructions and still the thing won't go. Anyway, we got it up and running and I hope we can fine tune it a bit, so far it's cutting nicely.

Cheers,

It would be good to know what machine you are using. That would be helpful.

Do you have cut charts for the machine?

There are two possible reasons that spring to mind.

1. The probe height is wrong so you are piercing too high and loosing the arc.

2. the par port may be a high impedance circuit so current flowing through the circuit is less than the minimum requirement of the AcOK dry contacts (eg. relay) inside the plasma cutter. This results in intermittent operation, much gnashing of teeth and countless wasted hours (ask me how I know this).

Item 2 can be fixed by using a pull up or pull down resistor at the input. Several cycles may be necessary to burn through built up oxide on the contacts before reliable operation is restored.

CFE wrote:

I thought I made clear that we do have an ARC OK signal available from the plasma cutter, and I watched all the pins connected to it in HAL show and they all work. But when I use mode 1 then I get "valid arc error lost", don't know why. In mode 0 the machine works.
,

Can you elaborate Exactly what the machine is doing when it looses the arc ok signal?

Even better if you could take a video on your phone and post it.