Hi,
Hopefully there's a simple solution that is just under my nose that I'm missing; here's my situation.  I'm trying to figure out how to keep my spindle from turning on with a drag knife on an ATC machine without having to use an intermediary program or separate drag knife file.

Background- We just got our second machine, which is a Mach3 system. Our first is a Syntec (Taiwanese) system.  With the material I'm cutting (PSA and paper backed foam) first we have a variety of router bits come by and cut the surface, then we follow with a Donek D2 drag knife.  I've set my drag knife in VCarve as an end mill with a .1mm diameter and spindle speed of 0.  Everything has radii so I have no problems with sharp corners.  On the Syntec system, it just doesn't turn the spindle on with the spindle speed of 0; with the Mach3 when I tried the same technique I had a surprise and got to dive for the E-stop as it started to spin up!

So my questions are-
1: Is this best handled on the Mach3 end (modify the code somewhere to say "ignore any commands to turn on the spindle with T7" or "If the spindle speed is 0, don't turn on the spindle") or with VCarve ("Remove any commands to turn on the spindle with T7")?
2: Where can I get a walkthrough on how to do this that my Neanderthal mind can grasp?

Thanks!
-James

Edit your v Carve post processor to remove the M3 that starts the spindle, and use that post for your drag knife code.

If you edit the post processor in Notepad, just remove this line:
"[N][S ]M03"
or any others with an M3 in it.

Edit your v Carve post processor to remove the M3 that starts the spindle, and use that post for your drag knife code.

If you edit the post processor in Notepad, just remove this line:
"[N][S ]M03"
or any others with an M3 in it.

Thanks for the quick response!
That would get me two separate files, so I'd run all the normal router tools, then run the second file that's just the drag knife- correct?
Ideally I'd like to keep it all as a single file per sheet to reduce downtime and operator headache.  Is there a way that it can not post an M3 with only one tool while turning on the spindle for all the others?

Edit your v Carve post processor to remove the M3 that starts the spindle, and use that post for your drag knife code.

If you edit the post processor in Notepad, just remove this line:
"[N][S ]M03"
or any others with an M3 in it.

To get the machine up and running, we're going to run two separate files for now (one for everything but the drag knife and one for the drag knife only.  As such, I've removed every M03 in the drag knife post processor file, and confirmed that there are no M03s in the processed file.  If there is no tool change (IE the drag knife is in the spindle before I start the drag knife file) then it runs successfully.  However, if I start the program with a different tool in the spindle, the tool changes to the drag knife, it G00s over to its start location, and then the spindle turns on when it starts a G01.  Ran the same exact file each time.  Could this be related to the tool change macro?

Fortunately I had my hand on an E-stop and so hit that before the spindle fully spooled up, but it's still rather perplexing as to why it would do this.  Picture is from immediately after hitting E-stop, before I moved anything. I've also attached the post processor (changed the extension to .txt from .pp so it would upload) and the file it erred on.

Thanks again!
-James

So like you may have an M3 in your tool change macro. That's a very bad idea, as you've seen.