History of 3D printing - 3D Printing: The Basics and Beyond - page 13

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money for the company . Another company based in the Netherlands: Ultimaker, also

originated from the RepRap project. Other low-cost FDM printers include already men-
tioned UP!, Leapfrog, Airwolf, da Vinci, Printrbot, Pharaoh, Bukobot, Beethefirst, Mark
Forged, Edison, ZYYX, Quant 3D etc. The big companies have also joined the trend, 3D
Systems launched its own low-cost 3D printer “Cube” in 2012. Stratasys acquired Maker-
bot in 2013.

The patent situation for stereolithography was more complicated, some patents expired
long ago while others expired in 2013 and 2014. When Formlabs launched their “Form 1”
low-cost stereolithography printer on Kickstarter in 2012 they were sued by 3D Systems
for patent infringement. It did not stop other companies from releasing their low-cost ste-
reolithography or DLP printers. In a short period of time the B9 Creator, Pegasus Touch,
Peachy Printer, OWL Nano and the XFAB hit the market. These were followed in a second
wave by names such as Solidator, Uncia, LumiFold, Nova, Titan 1, M-one, Stalactite etc.

The core patents for selective laser sintering (SLS), originally patented by Dr. Carl Deck-
ard, expired in 2014. It did not result in an immediate wave of low-cost SLS printers like
in the case with FDM and stereolithography. There were some obvious reason for this. SLS
uses a laser that is much more powerful than the one used in the stereolithography process.
While the laser used in stereolithography is comparable to the ones used in a projector or a
Blu-ray players, the SLS laser are tens of thousands of times more powerful than the pock-
et laser pointers that can hurt your eyes. [ix] The equipment used in the SLS process is more
complicated and costs more. The plastic powder used in the process is also more dangerous
to handle.

Despite these obstacles a few attempts to make low cost SLS printers still took off before
the expiration of the core patent for SLS. RepRap started an open source SLS project in
2013. Metalbot was a project that tried to make the first open source metal printer using
direct metal laser sintering. In a way it could be said that the SLS patent was circumven-
ted years ago by Danish 3D printer manufacturer BluePrinter, which is a low-cost alternat-
ive to SLS. Their Selective Heat Sintering technique uses plastic powder just like SLS but
thermal print heads are applied instead of laser.

In the end of 2014 the market for low cost SLS printers finally started moving when
UK company Norge, Swiss start-up Sintratec and Italian 3D printer maker Sharebot all
launched low-priced SLS printers for plastic printing.