There is an issue with the vcarve sop book, it says to save as a file type that isn’t in option in the current vcarve software. I think it has to do with changing bits in the software ? It doesn’t seem to want to save the file in a way that can change bits.
Are you referring to the GCode file? There’s no standard extension for those; sometimes you see .nc or .gcode. I may have added .txt as an option in VCarve so that you can double-click it on the CNC computer and Notepad will open it without complaint.
I’ll look at it.
The sop gives an extension that is needed so we can change bits between modes (such as the v bit in the sop). The software won’t let you run two different bits right now.
I think I figured out what’s going on. On the middle computer, the machine selection was set to the generic “large” machine rather than “PA-1000”.
The post processors for “large” have different capabilities than the one for our machine. After changing the machine to “PA-1000”, the post processor selection changed back to “Mach2/3 ATC Arcs (inch) (*.txt)” which will handle tool changes.
Off topic: I’m assuming the router doesn’t care about file extensions at all. Is the program on the windows machine what actually interprets the gcode and sends instructions to the router? What format are the insturctions the machine actually reads, and does the router have memory or does the computer have to communicate each step to the cnc router as it cuts?
Awesome! Thanks for figuring that out
The file you export from V-Carve and transfer to the CNC computer contains “G code”. It’s a readable text file, hence the .txt extension. That way if you want to look at it, you can just double-click it and Notepad will open it. I think I mis-remembered, and I configured Mach3 to use .txt as a default extension in addition to .nc. VCarve already offers the .txt extension by default.
G code contains very low-level instructions to the router, one per line, like G1X1.2Y2.4 F20, meaning “move in a straight line at feed rate 20 inches/minute to coordinates X=1,2 Y=2.4”
You might want to look at a file to see the comment lines at the top that VCarve put in about the tools used, or to scan the X/Y/Z coordinates to see if they’re positive or negative. If all your X and Y values are positive, the origin is the lower left corner of the workpiece. If the Z values are positive, then the Z zero reference is the machine bed, but if they’re negative, it’s the material top. Mostly it’s a sanity check to make sure the file is what you expect it to be.
Mach3 on the CNC computer talks to the red control box under the router bed over a dedicated network connection. At the other end of the cable is a Smooth Stepper board. Mach3 processes the G code one line at a time, and figures out how to get the router from its current position to the new position, and sends an instruction to the Smooth Stepper to generate pulses for the X, Y, and Z motors, each at the different rate, for the right amount of time. The pulses go to a Gecko G540 stepper motor driver for each axis, which energizes the coils in the motors, and then things move.
The Smooth Stepper reports the machine position back to Mach3 as it moves, so it can show that on the screen. When the current instruction is done, the Smooth Stepper says “next, please” to Mach3.
This is different than the laser cutter, where the computer can transfer the file to the machine and then you run it from there, without needing the computer anymore.
I don’t recall the numbers for the big CNC, but I was working on the little one recently, and that one has 10,000 steps per inch of motion in any axis.
This might be more than you wanted to know. 
Thanks! That’s pretty much exactly how much i wanted to know