Editor's Note: This article, part two in a series by Eric Brown, includes a buying guide for open source and Linux-friendly 3D printers. For more background on open source printers see part one: Open Source Pushes 3D Printers to Success.
3D printers run on simple microcontrollers – many of them based on the open Arduino hacker platform -- and are controlled by desktop PCs like any other printer. Almost all the open source printers -- and almost none of the proprietary designs – support Linux desktops, in addition to Windows and Mac.
With MakerBot and RepRap printers, users can draft their own designs using any CAD software, including open source programs like TinkerCAD and 123D Design, or download a CAD-generated .stl file from an open repository like Thingiverse or GrabCAD. The designs are run through a slicing program, such as the open source Slic3r, which converts the designs into layer data. This data is processed by a printer program that translates the sliced CAD drawings into machine code. More and more printer programs like Printrun or Repeteir-Host bundle a slicing program.
3D Printers on the Make
There's considerable overlap between 3D printer hackers and open hardware developers using embedded Linux. For example, O'Reilly's Make Magazine, the leading 3D printer resource, also regularly covers open Linux projects like Raspberry Pi. At Make, and the related Maker Faire, 3D printing is just one part of the wider, FOSS-oriented "Maker" movement, which spans everything from Arduino- and Linux-based gadgets to digitally-designed crafts. Last week O'Reilly spun off the Maker division as a company called Make Media.
Ten of the 15 desktop models on Make's 3D printer review page are open source. In addition to the previously mentioned Printrbot, Solidoodle, Type A, and Ultimaker "original" systems, other open models listed include the low-cost RepRap Huxley derivative SeeMeCNC, as well as other RepRap-based printers that range from $1,300 to $1,700, including Trinity Labs' MendelMaxPro, Deezmaker's Bukobot 8, MakerGear's M2, and Aleph Object's Lulzbot AO-100.
Castle Island's The Worldwide Guide to Rapid Prototyping offers another recent 3D printing guide, which also lists open source models like PP3DP's Up! printers, Bits from Bytes' RapMan, and the Fab&Home project's printer kit design. The latter, which emerged from Cornell University, uses a different syringe-based additive fabrication technology that is less precise than thermoplastic extruders, but supports a a variety of liquid materials, including silicone, cement, stainless steel, and even chocolate and cheese. The craft market is literally eating it up.
Most of the open source desktop models support both biodegradable PLA and stronger, non-degradable ABS plastics, and some can extrude water-soluble PVA plastic to form plastic supports for the object during fabrication. Some offer dual extruders for making PVA supports and applying multiple colors.
Other feature criteria include speed, resolution, chassis type, axis extendability, heating platform temperature, accessories, and the presence of an SD slot, which enables printing without an attached PC. Print volume generally ranges from four- to 10-inch cubes.
Future Print: Metal, Resin, and Web Interfaces
According a survey conducted last year by Statistical Studies of Peer Production, wish-list items include lower printer and materials prices, as well as high-end features like faster speed, better quality, and metal printing. In particular, Jarkko Moilanen, founder of the P2P Foundation funded research group, expects metal to come to more desktop 3D printers, which would greatly expand the range of end products. Already, a RepRap spinoff called MetalicaRap is developing an electron beam 3D printer that supports metal and can also be used to fabricate solar cells.
At CES, Kickstarter darling Formlabs unveiled its Form 1 stereolithographic desktop printer, which is touted as printing high-precision 3D objects using lasers and plastic resin. It appears to be a proprietary product, however, and it's being contested by 3D Systems in a patent lawsuit.
Eventually, Moilanen expects even more exotic materials to be supported, including nano materials, which will open up applications such as custom medical devices and tissue engineering. Here, open source has an early champion with the openMaterials project.
As far as we know, there are no embedded Linux 3D printers, which would likely be overkill. Yet, some 2D printers run Linux, and the Raspberry Pi has already been hacked to control 3D printers. Moilanen says he has considered using the Pi in an integrated design.
The need for more powerful processors and embedded firmware may grow, says Moilanen, as the devices grow more complex and start requiring direct web access. "I'm expecting we'll see web connections arrive on 3D printers, so they can be used just like laser printers are used now," he says.
One key future direction is cloud-based 3D printing. Already, services like market leader Shapeways, as well as Ponoko and i.Materialise, have found success with designers and engineers who would rather upload CAD files than tinker with hardware. Since their more advanced fabrication devices support multiple plastics, as well as metal and ceramics, some 3D printer owners use the services when their designs outgrow their own machines. As easy-to-use, browser-based CAD programs like TinkerCAD and 3DTin mature, cloud-based 3D printing services could greatly expand their reach to consumers, says Moilanen.
Open source and Linux compatible 3D printers
Below are the 10 open source, Linux-compatible models of the 15 products listed on Make Magazine's reviewed 3D printer page. The other five are all proprietary and except for the newly-proprietary, best-selling Replicator 2, they lack Linux support. Models listed below all support Linux, Mac, and Windows PCs. Unless otherwise noted, all devices support both PLA and ABS plastics, and prices are for assembled models:
Bukobot 8 (Deezmaker)– RepRap-based design, extendable in any axis, supports PVA - $1,385
Lulzbot AO-100 (Aleph Object)- basic RepRap MendalMax design with good accessories - $1,735
M2 (MakerGear)– RepRap Mendel/Pruse design with steel frame, big print volume - $1,499
MendelMaxPro (Trinity Labs)– RepRap Mendel-based with fast-heating 200W glass platform, supports PVA - $1,295
Printrbot LC (Printrbot)– Kickstarter newcomer, extendable in any axis - $799
Printrbot Jr. (Printrbot)– Cheapest, smallest 3D printer around, limited to 4-inch cube, PLA only - $399
Replicator 2 (Makerbot)– Latest version of best seller, higher end, Linux but (newly) not open source, PLA only - $2,199
SeeMeCNC H1.1 (SeeMeCNC)– DIY oriented RepRap Huxley spinoff with injected molded parts, supports PVA - $189 to $594 kit only
Solidoodle 2 (Solidoodle)- Affordable, fully-enclosed original design - $499 - $699
Type A Series 1 (Type A Machines)– Big 9-cubic-inch volume, high accuracy, supports PVA - $1,400
Ultimaker (Ultimaker) – Fast, 150mm/sec. speed, 8.3-cubic-inch volume – ($1,661 kit, incl. controller)