Tuesday, May 20, 2014

Maker Faire 2014 Highlights: Manufacturing

I stopped by the Full Spectrum Laser booth again this year.  People often ask me for recommendations on 3D printers, and I usually steer them toward lasers instead.  They’re super easy to use and work on a wide range of materials much cheaper than PLA filament.

Full Spectrum’s entry-level laser is $3500, far cheaper than the fancy Epilog lasers, so I’ve always figured that’s what I’d buy if I needed a laser.  Recently, though, a friend told me about hassles with the control software on a Full Spectrum laser.

I asked them about this at their booth, and they said that their latest “fifth generation” entry level lasers use a fancy control board from their more expensive models, and work a lot better than previous models.  So I’m cautiously optimistic, and still a big fan of lasers in general.

Looking Glass Factory slices up a 3D model and prints each slice on transparent film, then laminates the film together and embeds it in a solid block of plastic.  Here’s a 3d model of lower Manhattan they managed to scrape from Google Earth:

Imagineer James Durand and his wife (who’s a Mechanical Engineer at SpaceX, naturally) showed off James’s built-from-scratch blow-molding machine.  It heats polyethylene wax to 110C, injects it into a cooled metal mold, which solidifies the plastic touching the mold.  Then it blasts compressed air in to force out the remaining molten plastic, leaving a shell.

They cut the molds on the CNC mill in their living room, and had entertaining stories about second degree burns from early prototypes which motivated them to build the clear plastic cover sooner rather than later.

I believe they used an Industrino for the controller.  The electronics were nicely mounted over bus bars near the bottom of the enclosure.

I can’t find any photos of the completed machine, but that’s partly because they finished it just in time for Maker Faire!

Just across the aisle was this $600 injection-molding machine that’s surprisingly simple.  A heated reservoir melts plastic pellets and attaches to the spindle of your drill press.  Clamp your mold underneath the nozzle at the bottom of the reservoir, then force the plastic into the mold by lowering the quill on the drill press.

I got to see an actual PocketNC and meet Matt and Michelle, the husband-and-wife team of Mechanical Engineers designing an ambitious and beautiful 5-axis CNC mill from scratch.  They both quit their jobs a few years back to pursue their dream, and I really wish them well.

Their biggest holdup at the moment is software.  They have a few options when it comes to software for translating G-code, the decades-old language universally used by CNC mills for describing where to go and when, into the pulses that advance the stepper motors.

LinuxCNC is the oldest and most mature option, but also the hardest to hack on -- even the build process was intimidating to me, and I’m a software guy.

GRBL is another option.  This package has to be small, since it compiles small enough to fit on ATMEGA arduino boards.  I recently hacked RaspberryPi support into GRBL, and I was impressed at the code and comment quality.  Unfortunately for PocketNC, GRBL is built around cartesian coordinates: linear X, Y and Z axes all at right angles.  PocketNC, a 5-axis mill, has normal X, Y and Z axes, but also has two rotary axes.

The third option is the Syntheos TinyG.  They had a booth with a pendulum demo like this one showing off their third-derivative motion controller:

It’s not obvious to me which of these is best for PocketNC, but it is clear that we software guys should get our acts together so that we don’t hold up awesome projects like PocketNC.

1 comment:

Damien Miller said...

Nice roundup - thanks