3dprinterAt the end of January, a series of patents filed by Carl Deckard in the 1990s for selective laser sintering (SLS) — a high-quality 3D-printing technology — expired. With this technology back in play, people started to see big things for 3D printing coming up fast on the horizon.

Current desktop 3D-printing makes for mostly cheaper, plastic products. It is a relative novelty. SLS takes in powdered material, rather than plastic filament and uses a laser to bind it and create a solid structure. SLS printers can work using metal, glass, and ceramic materials. They can make things that are ready for sale, of the sort that to make today you’d need a really expensive printer for.

And so in the latter part of 2013, a chorus of onlookers began predicting a coming explosion in 3D printing technologies. There was a near consensus about how great this was going to be. The Economist mused about the boom. Quartz intimated in July that it was good as a done deal. Techcrunch called the day the SLS patents expired “a great day for makers.”

A roadblock between the current day and the future was being removed. The rhetoric was euphoric: “3D printing technologies will be blown wide open…” “Let the revolution begin…”

There was good reason for us all to be hopeful. The last time a major patent expired in 2009, which controlled the technology that squirts the melted plastic out the head of the 3D printer (or fused deposition modeling (FDM), if you want to sound technical) we got the first wave of explosions in consumer 3D printing. The RepRap Mendel fit a printer onto a desk immediately, provided a reference for everyone else to use and the response to it proved that there was a market for these machines. MakerBot Industries built on that and bought out a line of affordable consumer printers. By 2013, MakerBot was worth enough that 3D-printing giant Stratasys scooped it up for $403 million.

“As soon as the patents expired, everything exploded and went open-source, and now there are hundreds of FDM machines on the market. An FDM machine was $14,000 five years ago and now it’s $300,” Shapeways’ Duann Scott said last year, talking about the run on the market begun with the FDM patent expiring in 2009.

It happened then, so it was clearly going to happen now. Except, it didn’t. Or it hasn’t and won’t for a while. These patents expired at the end of January and in the intervening months we’ve heard nothing more about this supposed boom.

Crickets.

The more accurate truth is, that while it is nice to have another piece of 3D-printing intellectual property available again to manufacturers, this is just one piece of the patent bank that the 3D-printing giants like Stratasys and 3D Systems have locked down, many of which were only filed recently. There’re so many 3D-printing patents keeping technology siloed inside the bigger companies that the Electronic Frontier Foundation has started its own effort to free the market.

“The open source 3D printing movement has only been going for a very short period of time,” say Andrew Rutter, the founder of San Francisco’s Type A Machines, which manufactures 3D printers.

“There was 30 years of patent action before this. There’s a huge IP incumbency.”

Rutter uses the example of Stratasys’ Objet printers, which have several different heads and can print in up to 18 different materials. They can be used for industrial quality rapid prototyping. The individual printheads are mass produced and available, but the machine’s design is patented and strictly enforced.

So there’s a lot more holding the 3D-printer market back then just SLS patents. Rutter says that there have been patents for newer SLS techniques filed after the earliest ones that have just expired. He says that an IP expert he was talking to recently wasn’t convinced that an entire SLS machine could be built without violating one of these newer patents.

Score none for the little guy.

Besides these still very real hurdles, the difference between 2009 with the MakerBot explosion and 2014, is that FDM was the “easiest type of 3D printing,” Rutter says. “It’s not the simplest. Just the easiest to do with off the shelf ingredients.”

Not every expiring patent brings with it its own explosion. SLS techniques are complicated and dangerous, Rutter says. They involve lasers, for a start. With a dedicated effort, he thinks within five years we might start see some new innovation come out of it.

Patents for stereolithographic (or SLA) 3D printing techniques — which put down a thin layer of resin that is cured with a UV laser — expired 10 years ago, Rutter adds. And we’re only seeing machines start to make real, viable use of this technique now.

Which isn’t to take anything away from 2009 and the ensuing RepRap/MakerBot revolution. Rutter acknowledges that his own company wouldn’t exist without that patent becoming available and the ensuing innovation that came from it.

But sadly for open source 3D printing enthusiasts — or happily for the big companies that control the technology — 2009 was the exception, not the rule. Not every expiring patent is going to explode the market open.

The 3D printing revolution remains for now in the hands of the few, not the many.