Brandon Fosdick: From Rocket Science to Developing an Affordable SLS 3D Printer

Selective Laser Sintering (SLS) is probably the most exciting form of 3D printing technology today. Unfortunately though, it is mostly reserved for large corporations with equally large bank accounts. SLS 3D printers can cost up to and over $1 million, with even the cheaper ones coming in at around $100,000. Recently though, several companies have promised to bring more affordable SLS 3D printers to market, some at prices as low as $4,000. With this said, nothing has yet to completely materialize and become available to the general public.

One Aerospace Engineer, by the name of Brandon Fosdick, wanted an SLS 3D printer, but didn’t have the money to afford such a machine. So, what he did, is something not many of us would have been able to accomplish. He set out to build his very own laser sintering 3D printer, called the Ester, using his knowledge of engineering and programming to help along the way.

“The machine is about the size of a MakerBot Replicator,” Fosdick tells 3DPrint.com. “I was going for something that’s “desktop compatible”, and the Replicators at the local TechShop seem to be about the right size. The build volume is 100mm x 100mm x 100mm, but I hope to increase it for later iterations. I’d love to get to a 1m cube, but that wouldn’t fit on my desk any more.”

A few months ago, Fosdick accomplished the laser sintering of a tiny two-layer square, which at the time excited him greatly. Little did he know that in a few months he would have a machine capable of so much more.

For those of you unfamiliar with SLS technology, it is a method of 3D printing, using a powdered substance which is struck by a laser to become solidified. After the first layer is sintered, another thin layer of powder is placed on top, and then hit by the laser once again. This repeatedly occurs until a complete object is fabricated. “Otherwise, it works roughly the same as the FDM printers,” said Fosdick. “The lasers I’m using are the common 800nm laser diodes that you can get from eBay and Alilbaba. Currently I’m using a 500mW diode, but I have a pile of higher powered diodes sitting here waiting to be tested.”

The printer works in a similar fashion as a conventional FDM based desktop 3D printer, in that it uses the same XY gantry setup. The gantry moves the laser to trace out the printed portion of a layer of powder. Fosdick plans to look into a galvanometer based system for future iterations of the printer, but right now he is sticking with this system, as this is what he is most familiar with.

One topic that is brought up quite frequently when I discuss the potential for SLS based 3D printers in our homes, is that of toxicity. People claim that these machines give off toxic fumes, that can cause harm to individuals within the surrounding area.  With Fosdicks’ machine, however, which uses a polyester powder, that doesn’t seem to be a concern. “The powder itself has a distinct smell, but I haven’t noticed any extra fumes or smells while printing,” he told us. “Certainly nothing like ABS fumes.”

The polyester powder used in his 3D printer is the same powder used for coating bumpers, bike frames, and many other things. “I’m using it because it’s cheap, easy to find, and has a low melting point,” explained Fosdick. “It’s also non-toxic, which is nice. The cost and convenience of polyester are what originally caught my attention, and it has certainly helped move the project along, but I’m actively looking for alternative materials. My hope is that the printer will eventually be able to use a variety of materials. And some day, metals too.”

Fosdick tells us that he is targeting a 100 micron resolution on all axes, with a 150mm/s print speed. While the mechanism is already able to accomplish this, there is still some adjustments that need to be made with the powder and the optics before he is able to print with these specifications. Once he has it working, then he will more seriously think about potentially building more of them to sell.

“Like everyone else in this space, the idea of selling printers has been bouncing around in my head,” he tells us. “Now that I have something working, I’m looking into doing a Kickstarter. I started this project to scratch a personal itch because there’s a lack of affordable SLS printers, especially the kind that fit on a desk. I wanted one, so I made one. Unfortunately I’ve been so focused on getting it working that I haven’t put the proper thought or planning into the sales side of things. I’d like to do something like what Oculus did… sell a developer preview kit to help fund development of the “real” product, but everything is up in the air right now.”

Without a doubt, if and when Fosdick does launch a campaign to begin selling these 3D printers, he will certainly have many interested parties. The idea of an SLS-based desktop 3D printer is enough to get any tech geek excited.

Fosdick will be keeping us updated on this project via his Hackaday project page. What do you think? Would you consider purchasing the Ester 3D printer from Fosdick if he were to offer it for sale? What do you think about the feasibility of this project? Discuss in the Ester 3D printer forum thread on 3DPB.com.