Despite being around since the 1980s, metal additive manufacturing (AM) has only recently come into widespread use. As 3D printing continues to gain favor, many companies are beginning to look to metal AM for benefits. Egar Tool & Die, a Cambridge, Ontario, company in Canada that makes automotive stamping dies and other tools, is using metal 3D printing solutions from Desktop Metal to improve production of end-of-arm tooling (EOAT). While Egar initially relied on CNC machining to manufacture grippers, metal AM has offered significant benefits to production, including reduced manufacturing times, material and cost savings, and the ability to manufacture complex parts with ease.
“We originally had a plastic 3D printer, so that provided the little stepping-stone to get into 3D printing and what it could do,” says Colin Kool, director of additive manufacturing at Egar Tool & Die. “The Studio System from Desktop Metal is the bigger stepping-stone to get into metal 3D printing, which everybody really wants to be in.”
Cost, time savings
Egar has been using Desktop Metal’s Studio System – an office-friendly metal AM solution for prototypes and low-volume production – for a year and a half, and has already seen significant cost and time savings. When making EOAT, metal AM can cut production times from weeks to days.
“With the Studio System we were able to manufacture a test button with complex internal shapes,” Kool says. “Outsourcing this job would normally take 2 to 3 weeks and cost $300. Manufacturing in-house with metal AM cost $45 and took 5 days.”
Egar also achieved significant cost and material savings on their parallel grippers, reducing the cost by $100 per set, cutting tool weight in half, and enabling faster production.
Egar uses 17-4PH steel from Desktop Metal as their metal AM material, which can be flame-hardened to high hardness. The steel is soft coming out of the sinter oven and can be hardened fully or only in certain areas. This makes the material hard and durable, yet somewhat malleable.
“This is crucial because in most applications you want something to touch a part and something not to break. You want it to be hard and durable, especially on end-of-arm tooling, but you also want it to have a little bit of give if something does happen,” Kool says.
Part consolidation, complexity
Metal AM allows manufacturers to build features in small crevices where a CNC tool would have difficulty machining, using less material to create lighter parts. It also allows manufacturers to develop designs that would be difficult or impossible with a CNC machine, such as thin parts or parts with open areas.
“When you have lighter parts, the servos can move faster. So, designing something lighter reduces wear on equipment and increases production throughput,” says Ilya Mirman, vice president of marketing at Desktop Metal.
To make such parts, Egar uses generative design, which enables them to design a part for specific manufacturing methods, materials, and uses. The software optimizes the part, providing the highest material and cost savings possible.
“Generative design makes complexity relatively effortless,” Mirman says. “Using generative design, you can remove material where you have low stresses, where it’s not really needed. It’s kind of like a tree branch – the branch is only as thick as it needs to be to support what’s hanging off it.”
Additionally, the Studio System allows part consolidation – rather than machining multiple parts and combining them to make a more complex part, metal AM can print a single complex part, reducing assembly and parts to manage.
Despite the benefits of metal AM, some companies doing sheet metal stamping or producing progressive dies or other complex tooling are hesitant to use this technology because of the roughness of printed parts. While the surface finish of metal 3D-printed tools is generally good (about 3.0µm to 5.0µm), machined surfaces are 10x less rough (0.3µm to 0.5µm). However, for many applications, 3.0µm to 5.0µm is enough, and in Egar’s case, roughness is irrelevant to EOAT function.
“When people see the part doesn’t have the same surface finish or accuracy, it’s very easy, superficially, to say this process isn’t ready for prime time,” Mirman says. “However, with 3D printing you can make complex shapes that you couldn’t before. Maybe the part is still a little rough on the underside, but that’s a small price to pay for metal AM’s benefits.”
If roughness is an issue, there are plenty of ways to smooth a part such as mass finishing, polishing, and chemical etching. Part bottoms can also be machined to improve smoothness, which can take as little as 10 minutes on a lathe.
“You can orient a part during printing so that the area you care least about in terms of roughness is the area that’s affected, usually the bottom,” Mirman explains. “And we have technology coming soon that will make even the bottom of a part smooth.”
Once Egar reaches capacity on the Studio System, the company’s next step will be implementing a Shop System from Desktop Metal, a faster system designed for high-volume production parts. Egar also hopes to find new applications for their metal AM systems.
“I want to print everything – tooling, EOAT, copper electrodes. I don’t see it stopping anytime soon with Desktop Metal innovating as much as they are. Sky’s the limit, really,” Kool says.
Desktop Metal and Egar have already worked together to develop a copper electrode holder with conformal cooling for Egar’s resistance welding operations. The companies continue to collaborate, innovate, and improve each other’s technology.
“Companies like Egar push us to be better,” Mirman says. “They help us improve our systems by telling us what’s not working and what needs to be improved. That’s really critical at this early stage of the market.”