Plamsac air scribe set up

Who out there is running plasmac that also utilizes an air scribe and sheetcam? I'm still having a hard time wrapping my mind around how to make a tool change in the middle of the program. I'm not new to sheetcam or plasma at all, I probably average 4 hours of machine time a week for the last few years if I had to guess (using Mach 3). With my new plasma table, I have a 7i96, a scribe, and I'm running plamsac. I just don't see how you make plamsac swap tools (apply offset, and fire the scribe) for the layer or contour that you assign the plate marker tool too in sheetcam. I got plamsac up and running mostly this week, and I'm already blown away by all of the amazing built in features. It's definitely next level, and I really appreciate all of the time and effort that you all have put in to making this happen! What I lack in understanding on the software side, I hopefully make up for on the fabrication side. I'm a 25 year old teacher who just does fab work (almost full time:)) on the side, and I've got a long way to go, but I'm more than willing (I really want) to learn!

- Cody

This is the relevant section in the manual:
linuxcnc.org/docs/2.8/html/plasma/plasma...er-guide.html#scribe

If you use the postprocessor from here:
forum.linuxcnc.org/plasmac/38438-plasmac-post-processors#158270
there is a small doc in the download explaining what tools are required.

By way of explanation, Linuxcnc supports multiple spindles and also a tool changer. So basically, we load the tool (plasma or scribe) which sets the tool offsets (distance from the master tool - the torch). Then the spindle codes control the appropriate spindle (torch or scribe).

Thanks, I am using that post, and I've read through the manual. I just have a hard time wrapping my brain around it. Also, my scribe is mounted to my z-axis. I see that in the documentation, the scribe offset is only done in the x and y. I need my z axis to sit at 3.125" (relative to the machine, material thickness doesn't matter for my set up) before it fires the scribe. I basically set it up so when the z axis is in its home position, it can fire the scribe. It's on a spring loaded scribe so the material thickness doesn't matter

CBEAR wrote:

Thanks, I am using that post, and I've read through the manual. I just have a hard time wrapping my brain around it. Also, my scribe is mounted to my z-axis. I see that in the documentation, the scribe offset is only done in the x and y. I need my z axis to sit at 3.125" (relative to the machine, material thickness doesn't matter for my set up) before it fires the scribe. I basically set it up so when the z axis is in its home position, it can fire the scribe. It's on a spring loaded scribe so the material thickness doesn't matter

Is 3.125" your normal home position?
thefabricator03 on the forum tested the initial scribe stuff out, his is mounted on a floating head activated with an air ram, hopefully he will chime in. The scribe-arm signal activates the air solenoid then after a delay the scribe-start signal activates the the scribe then X/Y motion begins.

I sent a long reply earlier, but just checked and my internet connection must have given out before it actually submitted. Yes, 3.125 is where my z axis homes. Mine is mounted to the floating head as well. As long as it goes to 3.125 before it starts the scribe, the material thickness won't matter. I've got the scribe on a spring loaded slide so that it can float up and down on the material to account for warping, etc. I know that after a program is done cutting, it automatically returns the z axis to wherever it was at the beginning of the program. If I always start z from home, when it changes tools, would it follow the same procedure? The scribe works great from the MDI command, I'm just not sure yet of how to make it recognize that it needs to change to the scribe.

CBEAR wrote:

I sent a long reply earlier, but just checked and my internet connection must have given out before it actually submitted. Yes, 3.125 is where my z axis homes. Mine is mounted to the floating head as well. As long as it goes to 3.125 before it starts the scribe, the material thickness won't matter. I've got the scribe on a spring loaded slide so that it can float up and down on the material to account for warping, etc. I know that after a program is done cutting, it automatically returns the z axis to wherever it was at the beginning of the program. If I always start z from home, when it changes tools, would it follow the same procedure?

Yes, in most cases Z would end up at the home position. There is no Z axis motion when scribing.

The scribe works great from the MDI command, I'm just not sure yet of how to make it recognize that it needs to change to the scribe.

The commands for this are:
T1 M6 - this selects tool #1 which is the scribe
G43 H0 - this applies the X/Y offsets for the scribe
M3 $1 S1 - this starts a scribe jobs

Tool #1 is the LinuxCNC tool number, not the PlasmaC material number.
You need to have the correct X/Y offsets in the LinuxCNC tool table.

I was able to make my offset changes in the tool file, but I'm now getting an error when I try to run a program utilizing the scribe.
The error says "requested tool 1 not found in the tool table"

Here is the first little bit of code from the program

;begin pre-amble
G20 (units: inches)
G40 (cutter compensation: off)
G90 (distance mode: absolute)
M52 P1 (adaptive feed: on)
M65 P2 (enable THC)
M65 P3 (enable torch)
M68 E3 Q0 (velocity 100%)
G64 P0.01 Q0.001 (tracking tolerances: 0.01")
F#<_hal[plasmac.cut-feed-rate]>
;end pre-amble
;
;begin material setup
T1 M6 (select scribing tool)
G43 H0 (apply tool offsets)
M190 P252 (air scribe material)
M66 P3 L3 Q2 (wait for valid change)
F#<_hal[plasmac.cut-feed-rate]>
;end material setup
;
;begin operation #1, scribing, 4.43"
G0 X1.68351 Y6.81831
M3 $1 S1 (scribe start)
G1 X1.79677 Y7.14268
M64P2 (THC Off)
G1 X1.82808 Y7.23237
G1 X1.84600 Y7.18037
M65P2 (THC On)
G1 X1.94028 Y6.90681
M64P2 (THC Off)
G1 X1.97123 Y6.81700