setup qtplasmac

fupeama wrote:

Hi, I'm building a plasma machine and I have some questions about how to set it up.
1. I would like to control the ARC override with an encoder so that. I don't want to use a mouse. When cutting, I look at the arc and the encoder would adjust the height as needed. Using a mouse is too complicated.


2.
when cutting thick material, I need the torch to go up after the arc is ignited so that the blasting material does not spray on the nozzle. I am attaching a picture describing this function. This is how original software handled it.
 

is it possible to setup qtplasmac for this features?
Thanks Martin



 

1:
I would guess that it could be made to be possible, but it is not currently. The better question would be is it necessary... Have you used QtPlasmaC at all? You mentioned "this is how the original software handled it", I am wondering what you were using. At any rate, QtPlasmaC has "Auto Volts" which might negate the need for what you're describing.

linuxcnc.org/docs/devel/html/plasma/qtplasmac.html#qt_thc


2:
That looks very much like a recreation of Hypertherm's diagram from their ARC GLIDE THC manual. QtPlasmaC follows that logic, with the exception of the "transfer arc" portion you describe. Again, it's probably possible, but I believe they do this so that they get a good transfer from pilot arc to cutting arc on High Definition plasma cutters.  It seems to be less about consumables and more about the ability to establish a valid arc.   

An excerpt from that manual "Transfer Height: When the arc transfers to the workpiece, it can be “stretched” to the pierce height. The transfer height is lower than the pierce height because initiating arc transfer at a high pierce height may result in the arc not transferring to the workpiece at all. Enter the Transfer Height as a percentage of the cut height or as an actual transfer height distance."

All that said, it doesn't mean there's not a use case out there for someone.  From a splashback standpoint, I would think it matters how thick of material you are cutting.   In the air plasma scene, I'm not sure it applies, most cut charts just go to "edge start" when that become a big deal.  

I'm curious what the use case is, IE, how thick of stuff are you piercing, what power source are you using, etc.

Puddle Jump is after piercing and before cut height.

You can control the sliders with the relevant halui pins.

What OP is asking is a Hypertherm HD feature for cutting thick material, so probe, go to lets call it "transfer" height usually 2 to 3mm, start the torch, as soon as it gets arcok it moves up another mm or two to awoid splashback to the nozzle, then slowly moves down during the pierce delay time to reach the cut height, then moves on to normal cutting.

I seem to recall quite some time back I asked whether it would be worthwhile adding this but from memory the consensus was that it wasn't really required.

Edit: found it forum.linuxcnc.org/plasma-laser/35449-an...nent?start=70#120725

Yup, me too, but cutting 20mm plates with plasma is the "industrial" domain requiring 5 and 6 figure price tags.
Had several instances of trying to cut that with say 120A used and cheap plasma source, it can be done, but the results are usually disapointing, and nozzles run out rather quickly.
On the other hand, adding an Oxy Acetylene torch to the plasma machine does that easily and with style!
Depending on the torch, up to 160mm thickness can be cut with good results.
Edit:
Here i can find Oxy torches that can do 100mm for 190 Euro new, gas tanks are a bit more pricy

I'd echo the sentiment of using QtPlasmaC for a bit, and see what you actually end up needing.  Likely much of the functionality already exists; there's been a lot of input from a wide range of users, ranging from hobbyists to industrial businesses over the last few years. 

That said, it is usually worth at least considering/discussing new ideas.