Beginner Plasmac Questions

My project is almost ready to start burning metal so I'm trying to study up on how PlasmaC actually works. And specifically I'm trying to figure out how the machine will responds to plasmac gcode .

I gather that the M3 $0 S1 command starts a whole cut sequence. This one line will do probing, go to pierce height, fire, wait for arcOk, delay, etc?

I know plasmac takes over the z. Does it only control z during cuts? Or is the z always controlled by plasmac even during jogs, rapids, etc? In other words, are literally ALL z motions within a gcode file ignored or just those in between M3 and M5? If z is ignored even outside of running gcode programs at what height does z travel? Is it the same as the Safe Height setting?

Are z limit switches strictly required? At the moment the only switch I've got installed is a float switch.

Finally, I am trying to digest all the information in the PlasmaC User Guide. In the mean time, is there something like a quick start guide out there? Just something really dumbed down and basic that walks you through getting a PP set up, processing a basic DXF, through to running your first cut on plasmac?

Are z limit switches strictly required? At the moment the only switch I've got installed is a float switch.

You don't really need limit switches but it is good to have a Z home switch set up as hoe is shared (this will act as a limit switch) at the top

then you can set up soft limits.

You can download Sheet Cam and use if for free, for small jobs. you need to import a DXF file into it. There is a post processor for it on the forum forum.linuxcnc.org/plasmac/38438-plasmac-post-processors

AgentWD40 wrote: My project is almost ready to start burning metal so I'm trying to study up on how PlasmaC actually works. And specifically I'm trying to figure out how the machine will responds to plasmac gcode .

I gather that the M3 $0 S1 command starts a whole cut sequence. This one line will do probing, go to pierce height, fire, wait for arcOk, delay, etc?

That's correct. Automagically; thank Phill.

I know plasmac takes over the z. Does it only control z during cuts? Or is the z always controlled by plasmac even during jogs, rapids, etc?

Plasmac controls Z from the time you press start until the job is finished. Every M3 $0 S1 will cause the cycle you described, probe, go to pierce height, fire, wait for arc-ok, delay, move, THC will engage based on the THC settings, etc. until the M5 is reached. Lather, Rinse, Repeat. You are free to control Z manually with the jog keys outside of running a program.

In other words, are literally ALL z motions within a gcode file ignored or just those in between M3 and M5?

If you use the Sheetcam PP, there wont be any Z movement in the G-Code. If you were to load a G-Code file with Z movements within the file, Plasmac will strip them out when you load the file (again, automagically).

If z is ignored even outside of running gcode programs at what height does z travel? Is it the same as the Safe Height setting?

I'm not sure I understand this question. But it is recommended that you always start a program with Z at the top of its travel. You are free to move Z around to say line up the torch before a cut, but it's best practice to jog it to the top before you start. The torch will probe, and do all of the height adjusting based on your settings in the config tab, and the material settings. Safe height will be what it uses when it is traveling around via non-cut movements while the program is running. At the end of the program, the torch will return to the top of travel.

That's actually not 100% accurate, at the end of the program, the torch will return to the height it was whenever you started the cut. But again, it's recommended that that be the top of the Z axis' travel.

Are z limit switches strictly required? At the moment the only switch I've got installed is a float switch.

No. You can set it up so that the axis will call wherever it is "home" when you home it. It will work off of soft limits from there. But, I've e-stopped the machine before parking the Z axis at the top of travel and then had to move it up manually enough times to tell you that it's worth the investment to put one on. And, it's recommended that you get all of this working before you run the Plasmac configurator.

Keep in mind that if you are using a 2 Joint Y axis Gantry setup, before homing each joint will be independent, and the normal Z jog keys may not jog Z like you expect. It was my experience that the Y jog keys jogged one Y Joint, and the Z keys jogged the other Y joint. Of course after it's homed and the two Y joints are married jogging goes back to normal. You can also set it up so that no jogging/movement can occur on any axis until the machine is homed (that's how I set mine to save me from myself). To do this, just put a - sign in front of the homing sequence value for all axes.

Finally, I am trying to digest all the information in the PlasmaC User Guide. In the mean time, is there something like a quick start guide out there? Just something really dumbed down and basic that walks you through getting a PP set up, processing a basic DXF, through to running your first cut on plasmac?

None that I'm aware of. I think we all sort of fumbled through it by either searching/asking here, and watching YouTube. There are a few great series for getting started with SheetCAM.

I also recently started with a plasma machine, but I always have to do with programming in my work.
I use the DXF2GCODE program to convert DXF to G code and have had good experiences with it.
The post processor can be easily adjusted here.
I have attached a simple sample program.

AgentWD40 wrote: In the mean time, is there something like a quick start guide out there? Just something really dumbed down and basic that walks you through getting a PP set up, processing a basic DXF, through to running your first cut on plasmac?

Post Processor and DXF are not parts of PlasmaC, they are CAD related and should be treated as such, so anything regarding them requires knowledge of the CAM software used to create the DXF and the underlying Post Processor. Editing the Post Processor to export gcode suitable for PlasmaC has been discussed on this forum more than once for SheetCAM and Fusion360:
www.google.com/search?source=hp&ei=3fA_X...wpCQYQ4dUDCAY&uact=5
www.google.com/search?ei=7fA_X6C1MNHxkwW...qfCEwQ4dUDCAs&uact=5

tommylight wrote: Post Processor and DXF are not parts of PlasmaC, they are CAD related and should be treated as such, so anything regarding them requires knowledge of the CAM software used to create the DXF and the underlying Post Processor. Editing the Post Processor to export gcode suitable for PlasmaC has been discussed on this forum more than once for SheetCAM and Fusion360:

I understand your point. But holistically these are certainly parts of the process from going from idea to physical part. A beginners basic tutorial/walkthrough through a whole tool chain with a very basic part aimed at plasmac could be helpful to beginners. I realize CAD/CAM are huge topics in of them selves and there are countless resources out there for those specific steps.

For example, here is a brain dead walkthrough written for people to get there feet wet with svg -> estlcam -> marlin (v1's cnc variant) that just works
docs.v1engineering.com/software/estlcam-basics/

I'm just wondering if this hand holding exists. A template to work off of could lessen the learning curve for folks. Don't get me wrong, I'm not complaining and I'll figure out eventually one way or the other!