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3D printing sans supports

Builders of 3D printers are looking for ways to eliminate support structures

The need to 3D-print supports during metal additive manufacturing processes prevents the technology from fulfilling its promise. iStock

Few in the additive manufacturing industry would argue that laser-based metal powder bed 3D printing has been a game-changer. Everyone from GE Additive to Materialise to Protolabs to Stratasys Direct, to name a few, is printing end-use metal parts these days, often in production quantities.

There’s just one fly in the additive ointment: postprocessing. Or, more specifically, the postprocessing needed to remove metal supports, those little scaffold-like structures that keep metal parts from curling up—and plastic parts from drooping—during the build process.

This secondary operation isn’t a huge deal, at least for prototype parts. But production quantities? That’s another story entirely. Because support removal is so onerous at higher volumes, a number of 3D printer manufacturers have developed technology to either eliminate supports or make them easy enough to remove that post-build CNC machining is no longer necessary (at least for support removal).

As a result, countless service bureaus and discrete manufacturers may soon discover that the equipment they’ve invested gazillions of dollars in has become more obsolete than Grandpa’s pocket watch.

What is this powder bed-buster? HP has one. Its Metal Jet system uses a photocurable binding agent to hold parts together during the build process. When done, the “green” part is decaked (cleaned of excess powder) and placed in a sintering furnace. Granted, some machining might be needed for close-tolerance dimensions or where fine finishes are required, but it’s also quite likely that many parts can just be given a quick ride in a parts tumbler and be put into service.

Desktop Metal and Markforged offer similar technology. (A little too similar, perhaps, given that the two companies have spent time in court fighting about patent infringements). With HP’s Metal Jet process, the parts emerge from the build chamber, receive a little cleanup, and head off to the furnace. And, again, machining is only necessary if the printer can’t meet accuracy requirements. To be clear, these are completely different additive technologies, so it’s not fair to compare them with laser-based powder bed machines.

OK, fine. But at least one such machine builder aims to eliminate supports and do so without the need for binders and sintering stations. I read an excellent article about this recently by colleague William Leventon. In it, he describes how 3D printer manufacturer VELO3D has developed a build strategy that eliminates the curling that plagues so many of its competitors. That, together with a noncontact recoater and some other technical wizardry, has allowed this relative newcomer to advertise its Sapphire system as the first “support free” metal powder 3D printer.

The message here is clear: The 3D-printing industry is one of rapid change, so who knows what tomorrow will bring? At any rate, there’s no reason to go sticking “For Sale” signs on your antique, two-year-old printers quite yet—a few small tweaks to the recoater, some shiny new optics, a handful of process refinements, and you too might be printing parts sans supports.

About the Author

Kip Hanson

Kip Hanson is a freelance writer with more than 35 years working in and writing about manufacturing. He lives in Tucson, Ariz.