3D Printers and Self-Replicating Machines

April 2011
by Bryan Bergeron, Editor

When the Apple LaserWriter first appeared on the market in 1985, the $5,000 laser printer and Macintosh computer helped to create the self-publishing industry. The LaserWriter and other desktop laser printers enabled small business owners and well-heeled computer enthusiasts to produce professional documents on their desktop.

Today, 3D printers are at about the same price point, with commercial models available for less than $10K. Although supplies are still expensive, this new price point is a significant improvement over the $30K - $50K required to buy entry-level technology only a few years ago. Moreover, there are a number of do-it-yourself 3D printers available, including the open source Cupcake CNC. Take a look at the Wikipedia entry for 3D printers for sample 3D objects and links to affordable DIY printers. From a robotics perspective, the 3D printers are a blend of servos, controllers, electronic valves, and software drivers that resemble ink-jet printing technology on steroids. Instead of spraying ink, these printers spray layer upon layer of plastic material. By laying down hundreds of layers or slices — as defined by 3D software — these printers can create small plastic objects of just about anything that can be imagined. Some experimenters have even used 3D printers to create parts for other 3D printers. Not quite self-replicating, but it’s getting there.

While the robotics technology in the machines is worthy of study, what these 3D printers produce is also exciting. If you’re into small robots, you can print just about any structural components you need. The technology isn’t quite there if you need to create small gears with fine teeth, but for wheels, chassis, mounts, and other plastic components, if you can draw it in a 3D graphics program, you can print it.

Like the early laser printers, I expect that the first wave of serious robotics use will be with groups. As a shared resource, say purchased by a robotics club, even entry-level commercial 3D printers may be affordable. However, if your goal isn’t to build miniature carpet crawlers but to explore the robotics involved in 3D printing, then an open source DIY printer is an option even for a personal project. Although you may be able to build your own 3D printer from scratch, a big issue is the 3D software that drives the printers. Unless you’re a 3D graphics programming wiz, you’ll want to be compatible with the drivers and other software that’s been developed for DIY 3D printers.

For now, you’ll need conventional motors, printed circuit boards, and other non-plastic parts to finish off your robots. This may change soon, given the work in conductive plastics and with printable circuits based on standard ink-jet technology. Take a look at ‘printed electronics’ on Wikipedia for a good introduction to the technology.

I expect that in the future, the digital version of SERVO will include source files for printing complete robots. Until then, if you’re experimenting with 3D printing, please consider sharing your experiences with your fellow readers. SV