Monthly Archives: December 2013

Everyone in the 3D printing community has been talkin’ about the oncoming expiration of patents that’ll revolutionize 3D printing in 2014. Up until very recently, I was just as excited as the rest of the folks, eagerly spreadin’ the good news. I even announced it at the World Maker Faire, where I was giving a 3D printing talk for MAKE.

However, about 2 months ago, it dawned on me that I didn’t actually know which patents will expire. Not only that, I didn’t know which technology these patents safeguarded. I became nervous when talking about the patents, and inquired specifics from other enthusiasts. Unfortunately, no one knew.

Thus I began my hunt for these patents, to understand exactly what will be released into public domain.

A lot of the sensationalistic news about the impending 3D printing revolution comes from a single article on Quartz, by Christopher Mims. It was titled “3D printing will explode in 2014, thanks to the expiration of key patents.”

It paraphrased Duann Scott, a 3D printing evangelist from Shapeways, and described a brief history of the rise of FDM 3D printers in today’s market, and the impact of expiring patents.

I learned from that article that the expiring patent will cover “laser sintering” technology, but nothing more specific than that. I assumed it meant SLS, but wasn’t quite sure because the article also described the Form1 printer as a “laser sintering” printer (Form1 is a SLA printer). There was an appended note correcting the mislabeled technology of the Form1 printer, and stated SLA was also covered by some of the critical patents mentioned in the article. I just got more confused.

I contacted Christopher Mims about the patent IDs of the patents he mentioned, and he admitted to not knowing them. He instead referred me to Duann Scott for more information. Unfortunately, Duann did not respond to my tweet.

Resuming the hunt on my own, I remembered 3D Systems, once upon a time, sued FormLabs for patent infringement. I started looking into related SLA patents, and discovered one that it will expire in April 2014:

Simultaneous Multiple Layer Curing in Stereolithiography
Filiing Date: April 25, 1994
Issue Date: January 28, 1997
Expiring: April 25, 2014
US Patent Number: US5597520

In MAKE’s Ultimate Guide to 3D Printing, I found an article listing a few soon-to-expire patents. Neither of the recently expiring patents they listed, US6007318 and US5554336, expire next year.

Method and Apparatus for Prototyping a Three-Dimensional Object
Filing Date: December 20, 1996
Issue Date: December 28, 1996
Expiring Date: December 20, 2016
US Patent Number: US6007318
Holder: ZCorp

Method and Apparatus for Producing a Three-Dimensional Object by Stereolithiography
Filing Date: June 5, 1995
Issue Date: September 10, 1996
Expiring Date: June 5, 2015
US Patent Number: US5554336
Holder: 3D Systems

None of these patents contain SLS processes, which is, I believe, what most 3D printing enthusiasts believe will become publicly available.  Things just got curious.

I used Google Patent search and searched for 3D printing related patents filed in 1994, which would expire next year.

There’s 3 from 3D Systems, and all are SLA methods.

There’s 6 from Stratasys and revolve around FDM, support removal, and other optimizations.

There’s none from Z Corp.

3D Systems, Stratasys, and Z Corporation are giant players in the 3D printing. None of their expiring patents are SLS-based.

Searching “selective laser sintering” yielded a handful of results from United Technologies Corporation.

Although I’ve never heard of them on the 3D printing circuit, their patents for apparatuses for multiple beam laser sintering and temperature controlled laser sintering seem relevant. Though, I am doubtful those are the ones preventing desktop SLS machines from appearing on the market today.

I took another approach in my search and looked at old SLS patents. To my surprise, some of them already expired!

Method for Selective Laser Sintering with Layerwise Cross-Scanning
Filing Date: November 9, 1990
Issue Date:  October 13, 1992
Expired Date: November 9, 2010
US Patent Number: US5155324

I began to think this “revolution” next year is a hoax. After all, if several patents on SLS had already expired, where’s my mini-ProX 500?

Remembering an article a long time ago on why SLS patent expiration will not revolutionize the industry, I resigned myself to believing that SLS technology is already on the market and no one has executed it in the consumer marketplace.

Just when all hope was lost, I found stumbled onto a Hack A Day article. It clued me to search for patents with Carl R Decker as the inventor (the inventor of SLS). There they were. I couldn’t believe my eyes.

Apparatus For Producing Parts by Selective Sintering
Filing date: May 31, 1994
Issue Date: January 28, 1997
Expiration Date: May 31, 2014
US Patent Number: US5597589

Multiple Material Systems for Selective Beam Sintering
Filing date: March 21, 1994
Issue Date: January 17, 1995
Expiration Date: March 21, 2014
US Patent Number: US5382308

Everyone was right!

I’m so excited!!!


I am never ordering online from American Apparel again.


Last night I bought a dress from them, and was checking using Paypal.

On the final order confirmation page, I noticed the shipping address was incorrect and corrected it.


Minutes later, I get a confirmation email with the olde, incorrect address.

Surprised, I immediately email customer service to fix this problem. (I couldn’t call ’cause calling service was closed for the night).

This morning, I wake up a shipping confirmation to the incorrect address.


I call up customer service, explain what happened, and was responded with, “we can’t do anything.”

American Apparel, go hire some engineers to fix this problem.


Now, I’m out $50, and not getting anything >=[