[uyqah]

Although this part of the fourm seems pretty dead, i figured i would ask anyway.

Im planning on building a pen/sharpie plotter for drawing on foamboard. I have the structure and logistics of the machine all planned out and designed. The only thing thats stopping me is, i don't know what computer software and control system to use for the setup. The machine is going to be 2 axis with one stepper motor for each axis. The pen is going to be moved with a servo motor.

I have never seen nor used a cnc pen plotter, but i have operated 3d printers and CNC routers, so im not completely clueless.

Free software is best. I don't have thousands of dollars to drop on this machine, but if need be, i will pay for software.

Any input is helpful. I can change the design of the machine to fit the requirements for software. I haven't began gathering parts yet. Thanks in advance.

[aarggh]

If you don't want to pay for commercial software like Mach3, your pretty much limited to ones like Linux CNC which will do exactly as you need. What mechanism are you using for raising and lowering the pen itself? You mention a servo, so is this a 3 axis machine?

cheers, Ian

[SteveWill]

As aarggh said Mach 3 and Linux CNC are the main hobby machine control. You can get the older version of CamBam for free it is on their web site. For drawing. I would look at inkscape, DraftSight, both free Punch! ViaCAD 3D v8 if you look around for older version should be able to get for around $40 us. For lettering look at f-engrave, to look at your g-code use NC Corrector v4.0. All are free except Mach 3 and Punch! ViaCAD.

[uyqah]

Ill look into that software. And right now im planning on using a servo motor attached to an arm holding the pen. If using something else would be simpler, let me know. I guess the pen movement adds another axis. I didn't really consider that.

[uyqah]

So ive looked at Linuxcnc and it looks like it should be able to do what i need. Now i need to know, what driver board should i use? I was looking at this usb interface I could switch out my servo with a small stepper just to simplify settup.

[uyqah]

This breakout board might work even better. Since it has the relay connection, i could use that to control a servo using a microcontroler. Only issue is that im not sure if my computer has a parallel port on it or not. ill have to check when i get home from work. If not, i should be able to find one with a parallel port on it.

[aarggh]

If your planning on using Linux CNC and using three motors, why not just make all of them steppers and that way you have a 3 axis machine, instead of worrying about using relays to raise/lower a servo independently?

On commercial PCB routers they have a small engraver usually mounted via a solenoid, driven by a relay to raise or lower it as they only need less than a few mm clearance, but making it a 3 axis machine would be far better and versatile IMHO. It would be hard to cater for varying sizes of material without a 3 axis configuration.

cheers, Ian

[uyqah]

As i do more research, it will be better in the long term to go with 3 steppers rather than a servo. Eventually i want to convert the machine to a vinyl cutter, but not anytime soon after i build it. If i went with a 3 axis machine, what would you suggest for a control system? Would the break out board with the parallel connector work easily? (I did check, and the computer that im going to set linuxcnc up on does have a parallel port)