Desktop Metal’s CTO on the Next Generation of Metal 3D Printing
Michael Molitch-Hou posted on June 12, 2017 | 7361 views

Ahead of RAPID+TCT 2017, an exciting startup known as Desktop Metal finally came out of stealth mode after almost two years to reveal not one, but two new additive manufacturing (AM) technologies. Even before the big unveil, the startup’s technology received a hefty vote of confidence in the form of $97 million in funding raised from GV (formerly Google Ventures), the BMW Group, Lowe’s, GE, Saudi Aramco, Lux Capital, Stratasys, NEA and Kleiner Perkins Caufield & Byers.

To learn more about the new systems showcased at RAPID+TCT, ENGINEERING.com spoke to Jonah Myerberg, cofounder and chief technology officer of Desktop Metal.

Founding Desktop Metal

Myerberg has been working with cofounder and CEO of Desktop Metal RicFulop since 2005, when he joined Fulop’s lithium battery company A123Systems. While Myerberg continued in batteries, Fulop entered the world of venture capital, funding and sitting on the boards of a number of startups that readers will be familiar with, including Proto Labs, Onshape and Markforged.

“He was really exploring this space of 3D printing and AM, but also 3D modeling,” Myerberg said.“He saw a lot of demand for metal 3D printing in his investments, but he didn’t see a lot of people entering the market with any really good technology. So, the two of us kicked around the idea of a better way of printing metal parts. What we saw when we looked at metal 3D printing in 2014 and 2015 was an intention to scale a powder bed process into mass, put more lasers on the machine and make it go faster. There wasn’t new technology coming out, and we weren’t convinced that a laser powder bed was the answer.”

In 2014, Myerberg and Fulop began exploring new processes for metal 3D printing and came across five or six different technologies that could be viable. Three months later, those options were whittled down to what would eventually become the company’s core technologies.

Desktop Metal was founded in 2015 and recruited a number of material scientists and other engineers from MIT.By May of this year, the company had raised $97 million and was ready to unveil the Studio and Production Systems.

From Metal Rapid Prototyping to Metal AM

The DM Studio System is designed for safe metal rapid prototyping in the office or shop. With a price of $120,000, it’s is much less expensive than industrial powder bed fusion systems.

The DM Studio System is described as the first office-friendly metal 3D printer. On the right is the microwave-enhanced sintering furnace. (Image courtesy of Desktop Metal.)
The DM Studio System is described as the first office-friendly metal 3D printer. On the right is the microwave-enhanced sintering furnace. (Image courtesy of Desktop Metal.)

Rather than using expensive, high-powered lasers, the DM Studio System relies on what Desktop Metal dubs Bound Metal Deposition (BMD). BMD sees metal powder bound in a plastic matrix melted and deposited onto a print bed in a method similar to fused filament fabrication (FFF) or fused deposition modeling.

The DM Production System, as one might guess from the title, is for batch production of metal parts. It is expected to cost around $360,000, with additional equipment pricing to be determined, and is described as being 100 times faster than powder bed fusion technologies. It achieves this through the use of Single Pass Jetting, in which an inkjet print head deposits a binder onto a bed of metal powder and heats it in a single pass so that, with each move of the print head, another layer of a build job is made.

The DM Production System is described as 100 times faster than existing metalpowder bed fusion technologies. (Image courtesy of Desktop Metal.)
The DM Production System is described as 100 times faster than existing metalpowder bed fusion technologies. (Image courtesy of Desktop Metal.)

Once printed, parts made on either the Studio or Production systems are placed into a microwave-enhanced furnace created by Desktop Metal. By printing an interface layer using a specialty agent, the sintered parts can be removed from their support structures by hand, meaning that no cutting tools are required.

The two technologies are complimentary, according to Myerberg. Engineers are meant to be able to both rapidly prototype with AM and then manufacture with AM, as well. “Our vision was that we would allow engineers to do something that they’ve never been able to do before: Design for additive, prototype in additive and then head to production in additive. This has been the promise of AM, but there really hasn’t been a way for them to do it.”

Thanks to dropping costs in FFF, it’s possible for engineers to prototype rapidly in plastic using a machine that can cost a few hundred or a few thousand dollars. Until recently, not only has metal 3D printing not been available at the desktop level before, but mass manufacturing with metal AM has also been very difficult to come by.

That means that, even if a metal prototype were 3Dprinted, engineers would still have to tailor their designs for a specific mass manufacturing technique, such as injection molding or stamping. As a result, none of the advantages possible with 3D printing, such as geometric complexity, could actually be implemented in a mass-produced part.

MIM Materials and Microwave Sintering

Compared to powder bed fusion processes, Desktop Metal has a potentially huge materials portfolio. This is due to the fact that the company does not have to reinvent the wheel when it comes to the metals its processes will use. Instead, the company is turning to existing materials makers in the metal injection molding (MIM) field.

“MIM feedstock has been around for 40 years, has been refined and developed and is now a mature technology that is very well understood,” Myerberg said. “The feedstocks are very reliable, and the shrinkage rates are very repeatable, which is kind of the biggest concern with printing MIM materials.”

(Right) A yoke for a brake assembly produced with the DM Studio System as a replacement part for heavy machinery. (Left) The original part that was cast and machined. (Image courtesy of Desktop Metal.)
(Right) A yoke for a brake assembly produced with the DM Studio System as a replacement part for heavy machinery. (Left) The original part that was cast and machined. (Image courtesy of Desktop Metal.)

For the DM Studio System, these powders are mixed into the company’s binding material, which is put into the cartridges for the printer. For the DM Production System, no additional processes are necessary. Because Desktop Metal has characterized the morphology and powder size distribution for its metal powders, users can shop for metal powders on their own. This means that customers can turn to an existing and trusted supplier and hand them the specs with the hope of receiving materials that fit within the proper parameters for 3D printing on the DM Production System.

“Take the BMWs of the world that already have a relationship with a supplier, like Carpenter, and they want to use Carpenter materials in their parts,” Myerberg explained. “We say, ‘Great, go to Carpenter, buy its powders and use them in our systems.’ That way they can negotiate prices without Desktop Metal standing in the way. That really resonates with our customers.”

Along with the MIM powders, Desktop Metal’s technology has been designed to work with a specialty furnace. By combining conduction and microwaves, parts are debound and sintered much more quickly than in a traditional conduction furnace. On top of that, the ovens are cloud connected and rely on software that tailors the sintering schedule to the geometry of the part. This ensures uniform shrinkage through the parts.

“We knew that we had to provide a system to our customers, not just the printer, but the full system that was finishing the part,” Myberger said. “What we discovered was that the furnace process is super critical for the quality of the final part. You can’t just use an off-the-shelf furnace. Your geometry changes. Every part is different when you’re prototyping, so the furnace needs to be intelligent, needs to know what you’ve printed, needs to recognize geometry changes and needs to adjust its sintering schedule accordingly.”

The New Metal 3D Printing Industry

Desktop Metal has hit the scene just as some other new metal 3D printing technologies have been announced. For instance, XJet has developed a process for inkjetting metal nanoparticles, while Admatec has revealed a digital light processing technique for 3D printing green objects that are subsequently sintered. Collider has unveiled a method for injecting liquid metal into sacrificial molds, and Markforged’s Metal X 3D printer bears a resemblance to Desktop Metal’s own BMD.

“There’s no doubt that there are going to be entries into this type of printing technology over the course of the next many years,” Myerberg said.“We’re already seeing some, like the Metal X. We know the guys at Markforged very well, and we’re friends. We’re flattered that they are kind of following in our path. It’s a validation for us of the direction we took.”

Though there are a number of emerging metal 3D printing technologies, Myerberg believes that the company has not just the right technology, but the right team working on it. Without them, Desktop Metal may not have come out with its own furnace system, which is already a strong differentiator. The introduction of an interface layer that allows for removable supports is also unique to metal 3D printing.

Separable supports minimize post-processing. (Image courtesy of Desktop Metal.)
Separable supports minimize post-processing. (Image courtesy of Desktop Metal.)

Myerberg also pointed out that the software on which the company’s technology relies is different from the rest. “We’ve built our software from the ground up,” he said. “We slice and support the geometry based on all of our own algorithms. We also support the part in the furnace based upon the algorithms that we’ve created that know how the part is going to shrink. This is all geometry agnostic. You can take any geometry, and the software needs to know how to support not only during printing, but in sintering.”

Desktop Metal cofounders.Front left to right: CEO RicFulop, A. John Hart and Jonah Myerberg. Standing left to right: Yet Ming-Chiang, Chris Schuh, Ely Sachs and Rick Chin. (Image courtesy of Desktop Metal.)
Desktop Metal cofounders. Front left to right: CEO RicFulop, A. John Hart and Jonah Myerberg. Standing left to right: Yet Ming-Chiang, Chris Schuh, Ely Sachs and Rick Chin. (Image courtesy of Desktop Metal.)

Regardless of any competition in the field, Desktop Metal has both the team and the partners to back it up. With a staff of MIT experts and investors from some of the biggest companies in the world, Desktop Metal is bringing some heavy clout to the industry. In turn, it may be able to transform both metal 3D printing and the world of manufacturing altogether.

To learn more about Desktop Metal, visit the company website.


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