Why Grid Logic and Fugo Precision were turning heads at RAPID + TCT 2024.
3D printing seems like a novel technology to many people, but it’s already been around for more than 30 years. In that time, the industry has aligned on classifying various additive manufacturing (AM) technologies, as evidenced in the seven process categories laid out in ISO/ASTM 52900:2021:
- Binder Jetting
- Directed Energy Deposition
- Material Extrusion
- Material Jetting
- Powder Bed Fusion
- Sheet Lamination
- Vat Photopolymerization
Although these generally well-understood processes have been used in various industries, they aren’t the only ways to 3D print parts. Two exhibitors in particular at this year’s RAPID + TCT tradeshow showcased technologies that don’t fit neatly into the above categories but could presage the future of additive manufacturing.
AM meets hot isostatic processing
While hot isostatic processing (HIP) is a common post-processing step in many 3D printing applications, it’s a core part of the AM tech stack at Grid Logic. “This is a dry powder print,” explains Jim Holcomb, director of product development at the Lapeer, Mich.-based company. “We can work with any metal or ceramic powder that will flow through our printer, and we haven’t found a lot that doesn’t.”
Unlike binder or material jetting, Grid Logic’s approach doesn’t use any liquid component. Instead, all the powder layers are deposited into a sealed container (the “can”) and compressed slightly before the HIP cycle. “There’s no shift in the material,” Holcomb says, “We’re shipping cans four hours away and we don’t get any shift after compaction. The parts are 100% dense with no layering or texturing.”
The machine on display at RAPID prints with up to six different powders, one of which is a sacrificial support material. According to Holcomb, the company has been seeing a lot of interest in from clients researching bond diffusion in multi-material applications. “We do a lot of hard-facing copper alloys, as well as Inconel and stainless steels,” he says. “The next phase is doing functional gradients: being able to shift from one material to another in a single layer.”
Grid Logic uses a modified slicer software to create its own toolpaths. “All the engineering, all the design, all the building and fabrication of the printer is all done in-house,” Holcomb says. “If you come to us with a part, we’ll figure out the recipe and how to make it work, even vertically integrate a system for you.”
Centrifugal 3D printing
“The way I frame this is that it’s the difference between a propeller airplane and a jet airplane,” says Drew Padnick, president of Fugo Precision. “We’re the jet airplane.”
The jet airplane to which Padnick refers is the Fugo Model A, which his company claims to be the world’s first centrifugal 3D printer. It’s a bold analogy, but Padnick contends it’s also an apt one.
“[The Fugo A is] faster, it’s more precise, it has fewer mechanical parts that we’re moving,” he says. “Propeller engines were phased out when jet engines came in for very similar reasons.”
Looking at the layout of the Model A, the concept of a centrifugal 3D printer quickly becomes clear. The build envelope is unusually oblong at 50 inches by 8 inches by 5 inches, but that’s because it’s wrapped around the inside of the machine to form a hollow cylinder.
“This thing spins between 1,500 and 3,000 RPM while the material enters the chamber from underneath,” Padnick explains. “We’re using 20 lasers, which drop into the chamber from above to print the material. If you think of it like that carnival ride — the Gravitron — that’s a good way to visualize what’s happening to the material.”
As a result, Fugo claims it can achieve “layerless” 3D prints with 30-micron accuracy at 10 times the speed of traditional stereolithography using a comparably diverse range of photopolymers. In addition, the Model A incorporates post-processing so that parts can be printed, washed, dried and post-cured in the same machine.
“Since the advent of SLA and DLP technology, the single greatest problem with these printers has been the need for a mechanical means to spread the infinitely thin layers. With the Fugo Model A, we have solved this problem as our technology does not use any mechanical means to create layers during printing,” said Sasha Shkolns, Fugo Precision CTO in a press release.
One last point worth noting about the Model A: “We haven’t tested this,” Padnick admits, “but the science holds: we can print in outer space. Because we’re essentially creating our own gravity, we can print at low- and zero-G.”
Although those aren’t first applications the company is targeting with the Model A, they suggest that more unconventional approaches may be the key to bringing additive manufacturing to a wider array of terrestrial environments and applications.
