Why should a metal fabricator care about additive manufacturing?

At TRUMPF Inc.'s booth, metal 3-D printed parts for the dental industry were on display. Their small size allows many parts to be printed on a single powder-bed-fusion bed.

The immediate potential of additive manufacturing lies not in lofty conversations of a far different future, with a 3-D printer on every street corner printing anything a consumer could want, from thumb tacks to SUVs. The potential is in making life easier on the manufacturing shop floor, from General Electric and Lockheed all the way down to the mom-and-pop sheet metal job shop.

That message rang true during every conversation I had at RAPID+TCT, the additive manufacturing show held in Fort Worth this past April. And that’s saying something, considering I chatted with companies that offered an extraordinarily wide range of additive technologies serving a range of markets. You had printed error-proof fixtures for assembly in one booth, repaired airplane blades in another, dental implants in another.

The fact that additive is changing how people think about part design has spurred keen interest from investors, and with that interest comes hype. Will this industry change everything? Not really, at least not immediately.

A big reason why has to do with the industry’s elephant in the room: the post-processing. Most additive technologies require support structures that hold it in place as the part is being printed. Once it’s finished, those support structures need to be mechanically removed, and the part itself needs to be ground to a fine finish. That post-processing requires two things manufacturers lack: skilled people and time.

At the same time, additive isn’t all hype. There are some real opportunities to be had. That’s something Rich Baker, chief technology officer for Maple Plain, Minn.-based Proto Labs, knows all too well. An exhibitor at RAPID-TCT, Proto Labs offers not only 3-D printing of plastics and other nonmetals, but also plastic injection molding, machining, and, most recently, sheet metal fabrication, thanks to an acquisition the company made last year.

Working at a manufacturer that offers a wide range of services, Baker comes to the market with an objective view, so when asked about what’s real and what’s hype, he had an extensive answer.

“The hype is, ‘We’re consolidating all these parts together and, therefore, we’re eliminating all these steps, and we’re going to save a ton of money. But when you look at the use cases where that’s actually paid off, there are actually very few. You need to combine specific attributes like internal passages for fluid flow. [A 3-D printed part can have internal passages that just couldn’t be machined.] You also need a geometry that you can’t make any other way. Then it makes sense at today’s prices. Still, you do see some crossover for smaller parts, simply because of the number of parts you can fit on a build platform. This has made it work well for medical and dental applications.”

He added that in the metal 3-D printing space, metallurgical issues crop up too, particularly for applications that use certified materials. “When you’re printing metal, you’re doing metallurgy at the same time as the fabrication. Properties in the part depend on where they were made as well as the heat transfer. That adds complexity. In short, there’s a lot of hype about how easy it is to gain all this design freedom, but there’s a bunch of baggage coming with it.”

So what’s real?

“The costs of materials in general are going down, and that’s helping to lower the cost. There are companies out there now that have gotten material costs down and build rates up.” The material cost is still high, he said, but it’s much lower now than it was just a short time ago. That bodes well for the future.

“We also see fixturing and tooling as great applications. If you can’t get the tolerance or geometries you need by conventional means, then using additive for fixtures and tools really makes sense. At this event, Lockheed showed how it’s using printed fixtures and jigs extensively to simplify assembly. It’s low cost, and you don’t have to undergo the same qualification process [as you do for printed parts.]”

As I walked the show floor, I saw printers that I could see fitting in well at the various fabricators I’ve visited over the years. Want to print a fixture to hold a part for inspection or assembly? Maybe some one-off polycarbonate press brake tooling for low-tonnage jobs? Maybe a scale model of a sheet metal assembly? Perhaps a robot end effector? 3-D printing could serve those needs extraordinarily well.