Could this [part, fixture, gauge, tool] be 3-D printed?

Performing a metal additive process called Intelligent Layering, six milling heads quickly machine the surface after each layer is deposited. Photo courtesy of 3DEO.

Although additive manufacturing (AM) has been around for decades, it’s much younger than metal fabrication. That’s what makes it appeal to so many metal fabricators, including those who will be stopping by the Additive Manufacturing Pavilion at next month’s FABTECH® show in Atlanta. There’s an excitement to it, a feeling of untapped possibilities. There’s hype, of course, but within that hype are gems of opportunity, and sheet metal fabricators are just starting to find them.

For instance, they’re now printing various manufacturing aids, including press brake tools and backgauges; scale models; prototypes; assembly fixtures; even robotic end effectors for bending, welding, and pick-and-place applications. Advanced custom fabricators—like those specializing in tight-tolerance work for the medical, aerospace, and defense businesses—are looking to various metal additive technologies that could fill a need.

The pace of technological advancement is mindboggling. Not only are equipment companies developing new additive technologies and perfecting existing ones, but AM service bureaus (the industry’s term for a job shop) are developing their own AM methods too.

Consider metal additive manufacturing. Not too long ago, if you wanted to print something out of metal from scratch, you’d probably turn to powder bed fusion, in which a laser or other heat source builds up a metal part in a bed of powder.

Then a metal printing technology came along that resembles fused filament fabrication (FFF) printing, an extrusion-based printing process common among many plastic-part printers you find everywhere, from the office to a middle schooler’s classroom. Only this FFF printer uses cartridges of metal powder, similar to the material used by the metal injection molding (MIM) business. The company selling this extrusion-based printer, Burlington, Mass.-based Desktop Metal, calls the process Bound Metal Deposition™, or BMD. The process occurs over three steps: printing, debinding, and sintering.

“This is an office-friendly metal 3-D printing system,” said Larry Lyons, vice president, product, for Desktop Metal, at the RAPID+TCT show held in Fort Worth, Texas, back in March.

Turns out you now can print certain metal alloys layer by layer without a laser, electron beam, or similar heat source. Desktop Metal happens to be selling its machine to others, but another company on the West Coast is taking a different approach. Gardena, Calif.-based 3DEO is an AM service bureau that has its own patented metal printing process it calls Intelligent Layering®.

“We started two years ago,” said 3DEO President Matt Sand. “I’m one of the three founders, and the other two received their PhDs from the University of Southern California, and their degrees are in additive manufacturing. They were studying binder jetting processes using inkjet technology. And as a result of their technical expertise, we were able to invent a new process that’s similar to binder jetting, but the mechanisms of the underlying process are very different.”

Intelligent Layering uses metal powders similar to those used in MIM. While binder jetting uses inkjet heads to deposit binder, Intelligent Layering instead uses a custom spray system that deposits binder over an entire layer.

“Binder jetting will deposit binder very precisely on the bed, where the part sits,” Sand explained. “But we bind the entire layer, and then come in with CNC end mills and actually cut that layer.” The milling process, performed by six cutting tools suspended over the build area, occurs very quickly after each layer.

“We get all the precision of CNC milling, but we’re still building on a layer-by-layer basis,” Sand said, adding that the process produces so-called “green parts” that then need to be sintered in a furnace.

“The process is very high resolution and results in very high yields,” Sand continued. “When we’re running small, complex parts, we see each of our prints making at least 1,000 pieces a day. Combine this with the fact that we’re using relatively inexpensive MIM materials, we feel we have a process that can compete with traditional manufacturing.”

Sand added caveats common to the additive arena. “We’re really only competitive for complex parts, such as parts that need four to seven axes of machining capability. The parts also need to be about the size of a softball or smaller.”

For the past year 3DEO has been working with customers, shipping parts, and proving that the technology does indeed work in a production setting. And yes, the caveats remain; to be truly competitive, Intelligent Layering needs parts to be small and complex.

Thing is, considering the history of AM, those caveats are a moving target. Will parts always need to be complex and small? And again, AM doesn’t always need to be applied to the actual parts being made, but instead to the fixtures and tools used to aid manufacturing.

AM seems to be at an inflection point, and progressive fabricators are exploring their options. Say they have a sheet metal assembly with a complex machined component that they usually outsource to a machine shop. Does this component really need to be machined? Could this machined component be printed, perhaps with a new design to make the entire assembly better?

It’s with these questions in mind that the editorial team at FMA Communications is launching The Additive Report. Quarterly in print and constantly online, The Additive Report will cover this relatively young, evolving industry, discussing the methods and, especially, their application. It will challenge readers to continue asking the question: Could this part, fixture, gauge, or tool—made of metal, plastic, or composite—be printed?

For more information about The Additive Report and to sign up for a free subscription, visit www.theadditivereport.com.

Desktop Metal, www.desktopmetal.com

3DEO, www.3deo.co