Earlier this month, Formlabs brought me out to the MIT Media Lab for The Digital Factory, their first digital fabrication conference in conjunction with Desktop Metal. At the event, Formlabs unveiled its Fuse 1 SLS printer and we were given an exclusive behind-the-scenes look of the machine. Here's everything we know so far about how it works and the prints you can get out of it.
Selective Laser Sintering (SLS) uses a laser to bind together thin layers of a powdered medium (typically nylon) to form a finished model. The finished nylon model is very strong and can have relatively thin walls while retaining strength and flexibility. Any powder that is not sintered by the laser acts as support for the model allowing complex geometries to be printed successfully. Additionally, the entire volume of the print chamber can be packed with models - unlike other technologies that can only utilize the surface area of the print bed. When finished the print is encapsulated by all the loose powder in the build chamber. The print must be allowed to cool in the chamber as it will remain somewhat pliable until cool. The chamber is emptied and all the loose powder is cleaned away from the print. If the model is hollow it will need drain holes in order to remove any loose powder.
Due to the printing process, SLS parts will have a slightly rough surface texture and won't resolve very fine details as well as SLA resin prints. However, prints will be much stronger than most resin prints and cost less. In addition, parts do not need post-curing and are not UV-reactant like resin parts.
Typically SLS technology has only been available as large, industrial machines at $150,000+ so a four-figure benchtop unit is pretty exciting. While Formlabs isn't the first to introduce a benchtop unit at a price under six digits, they are the first U.S. based company to do so and at $10,000--a very reasonable price for a SLS machine.