I’ve had 3D printing on the brain for the past few weeks for some reason. I’ve been thinking about putting together a kit 3d printer to get started. I was thinking how I would like a relatively large work area (not the small limited 6″ or 8″ cubed that a lot of the cheaper printers provide.

Then last evening it came to me. The light bulb came on.
Use the milling machine as the printer! Just get a print head, and control it from the existing software (Mach3). The work area is huge, and the cost should be quite reasonable since I only need the extruding head. Between a good quality plastruder, and a temperature control board, it should be about $250 ($170 for the plastruder, stepper motor driver and $60 or so for the temp control board)

Feed speeds of a makerbot are around 40mm/s (2400mm/min). Currently I can do about 1000mm/min on my milling machine (which is 1/2 of the makerbot speeds) but with a ballscrew upgrade I should be able to do about 5000mm/min feed speeds (83mm/sec).
I have read about some kit 3D printers (like the Ultimaker) that can do 200-300 mm/sec feeds (12,000-18,000mm/min). I know my mill will never go that fast.

Resources:

Mach3 as 3dprinter software (here)

Good info on whats required in order to use Mach3 as the river software (here)