I don't have a 3D printer or a CNC. When I look at the cost of buying the whole kit for the mostly printed cnc ($450US) I can't justify the outlay for a separate printer. The mostly printed cnc is waaaaaay more versatile and can be easily adapted to 3D printing.
Like this example of it 3D printing: The skies the limit with this machine.
Ram,
You are entirely correct about the flexibility of the MPCNC... I've had a ball with it. I know I sound like a salesman but... again, I have no affiliation with Allted or MPCNC. I simply recognize some good engineering when I see it.
As you probably know by now, I've built 3 of them... all in a large-ish form factor suitable for cutting RC plane parts. All were a full 48" in one dimension, 32"/36"/48" for the other dimensions on the three machines, respectively. You can actually make them any size you want... only the belts, wire, and conduit lengths change. And while there are folks actually 3d-printing and/or milling wood, plastic, and aluminum with it, you'd need to keep a small-ish form factor for the sake of speed and rigidity. BUT, for foam cutting, the sky's the limit for this machine... as you've said.
The key to the MPCNC's unique-ness? It is a 3d printer at heart. It actually uses a very common board set (ArduinoMEGA/RAMPS1.4) used with 3d printers as well as the firmware (Marlin) to run it. So, the MPCNC itself, with an extruder mounted, is actually -- "natively" -- a very capable 3d printer; i.e. it's not an "add-on" capability as it would be with most CNC machines. By simply "faking out" the temperature controls and extruder drive in the Marlin config file allows the MPCNC to function as a CNC machine. To 3d print, change a couple of lines in the config file, upload the modified firmware to the Arduino, mount an extruder, and off you go, 3d printing again. So the line between CNC machine and 3d printer has been redrawn IMHO... actually ELIMINATED.
To be honest, the MPCNC is "different" from other CNC machines and not totally without its quirks. It takes some time getting used to. Using Marlin pretty much dictates using metric units (few 3d printers have sufficient print volume to warrant using "imperial" units) but that shouldn't be a problem for most of us; i.e. most RC aircraft can be readily "described" in millimeters. The gcode you generate also has to be Marlin-compatible... thankfully SketchUp/SketchUCAM and Estlcam have that post-processor already. Most other CAM programs probably have a "standard gcode" post-processor (or one close)... I have a friend who is using Aspire and VCarve and, last I heard, he had found something that seems to work for him. And Mach3, LinuxCNC, etc. don't know how to talk to the Arduino/RAMPS... so Pronterface and RepetierHost are the tools most often used. I'm still just learning about all this stuff myself... I'm sure I've missed something. You get the idea.
BUT running your CNC machine "headless" is great fun... no computer necessary! Just put your gcode file on a SD card, plug it into your LCD controller, select the plane you want to cut, and let 'er rip!
David
