When I made the move to 3D printing a few years ago, I imagined that by now I would have sold my milling machine, drill press, and other 'subtractive' technologies. The reality is that 3D printing is simply another tool in my prototyping toolbox. This additive technology isn't really clean or waste free — I’m constantly vacuuming starter strands of PLA and ABS from my shop floor. Plus, the technology isn't completely safe. There's the hot extruder, hot bed, and — as I recently discovered — danger in machining a 3D printout.