Inside metal fabrication at NASA

Spencer Wells, a NASA mechanical engineering technician, tackles some welding at the Prototype Development Laboratory at NASA’s Kennedy Space Center in Florida. NASA/Ben Smegelsky.

What’s it like to be a sheet metal fabricating expert at NASA? “Pretty cool,” said Spencer Wells, whose actual title is mechanical engineering technician, in the Prototype Development Laboratory (PDL) at the Kennedy Space Center in Florida.

Wells isn’t working on fabrications that other shops also might be doing—a new antibacterial gel dispenser for tourists, for example. The PDL team of engineers and engineering technicians are dedicated primarily to the design, fabrication, and testing of prototypes, test articles, and test support equipment for their NASA co-workers. At the time of this interview in November, Wells had just wrapped up work on a project for the Artemis program, which has the goal of putting astronauts back on the moon by 2024. (The first test launch of the Artemis program is scheduled for later this year.) But PDL also supports the research and technology development laboratories at the space center and other major projects that might involve NASA partners, a more common occurrence as private industry and the government’s leading space exploration experts work more closely together.

“It’s hard to explain the type of work we do. And the reason why it’s hard to say is not only because I can’t go into specifics, but also because we do so much here,” Wells said. “One week we supported an engineering group that wanted to test a new blanket material that was used for protection from heat. They wanted to know at what temperature it would fail. So they didn’t even necessarily walk out of here with a product, but they walked out of here with the answers they needed.

“The flipside of that is the next week we might fabricate an entire housing for electronics and avionics,” he continued. “That’s really the two ends of the spectrum.”

The space flight hardware is something that is a bit newer for the PDL, according to Wells. It had long been active in fabricating items such as ground support equipment, testing fixtures, mockups for training, and even some tooling, but building space flight components elevates the stakes. The PDL team needs to be at their best so that their fabrications don’t fail.

The PDL team comprises about 15 technicians who take on these engineering challenges and fabrication duties. They work mainly with aluminum, such as 5052, 6061, and 7075; some stainless steel; and a small amount of titanium. You won’t find too much mild steel in this lab.

Wells said that the PDL works on about 100 projects per year. Some can be turned around in a couple of hours, and others might take two months to finish. While some projects could be measured in days rather than hours, Wells said that they are respectful of deadlines. NASA has a lot of moving parts as it marches toward the end of major programs like Artemis, and no one wants to be responsible for throwing such important initiatives off schedule.

While the lab’s fabricating work schedule may be very different from that of most metal fabricators in the world, the tools of the trade aren’t. To accomplish most of the tasks, the technicians still need to cut, bend, and join metal.

“We’re far from a production shop here,” Wells said. “We’re basically a one-stop shop for prototyping. That’s why we have so many capabilities.

“So if you had engineers or scientists with an idea or a concept that needed to be worked through and it involved sheet metal or even composites that required fabricating, machining, or electrical work, they would have to go to the outside world and find a company to work on each of those areas. You would have to deal with multiple businesses. Instead, they come here. We work through all of those problems and get those engineers and scientists what they need.”

Wells works on one of three new camera housings. The thermal cameras will be added to Launch Pad 39B for the launch of Artemis I, the first in a series of missions that will enable human exploration to the moon and, ultimately, Mars.

The PDL upgraded its sheet metal cutting capabilities with the installation of a new waterjet about four years ago. Wells, who has been with the team for just two years, after almost 18 years in the aerospace industry, said his co-workers described the waterjet as a “game-changer,” allowing material to be cut precisely and quickly. The lab also has machining centers, 3D printers, and welding equipment that metal fabricators might have in their own shops.

The lab also had a 100-ton hydraulic press brake, but it wasn’t a machine that the other technicians really saw as a positive when it came to forming capability. Wells said that when he was hired, he became the primary sheet metal expert on staff. Most of the other technicians had machining backgrounds, and the brake simply couldn’t deliver the consistency and tolerances that they were used to getting with their CNC mills.

“They all kind of dreaded working with the press brake because they weren’t getting a lot of repeatability and the setups were lengthy,” Wells said. “They were basically just shying away from the sheet metal work if they could.”

Wells said that, relying on his experiences with older hydraulic press brakes, he introduced some practices to help reduce tooling setup time and the process time dedicated to delivering formed parts meeting specifications. The latter was an exercise in determination and patience, however, for those without a ton of press brake experience.

It also was getting hard to get replacement parts for the press brake, which was more than 20 years old. The only place to find those parts was on eBay, a supplier that’s not on any federal agency’s approved vendor list.

Early on Wells learned of a program within NASA that allowed labs to upgrade their equipment. It’s how the PDL purchased its waterjet, and it looked like a way that they could solve their bending dilemma. Wells started the process in 2019 and got approval to look at new press brakes in 2020.

Getting a Brake

When the search began for a new press brake, one of Wells’ co-workers suggested an electric brake, something he had seen at a tradeshow. Wells said he didn’t have any experience with that type of press brake, but he was intrigued to learn more. When he began to see this type of equipment in action, he liked what he saw.

“We thought with this type of press brake and with new software, it was going to allow us to do first part, right part every time,” Wells said.

In particular, the team gravitated to the SafanDarley E-Brake, which the company calls an “electronic” brake. It had a built-in light curtain, not added on as a safety measure after the brake was built. Wells may not have had experience with electric press brakes, but he had experienced the frustrations with add-on light curtains. More often than not, they were hindrances to production. The light curtain was too sensitive and shut down the braking action when the operator’s hands barely grazed the brake’s bending window. Wells said he had known operators to turn off the light curtains on their press brakes so that they could work without interruption.

The built-in light curtain can keep tabs on the bending area while also allowing other movement in the press brake window because the sensors focus on an area of about 30 mm, just over 1 in., where the bending takes place. If the integrated light curtain senses a presence that it shouldn’t, the ram stops within milliseconds. (The servomotors controlling the ram movement can stop it much more precisely than a hydraulic system.) Also, if there’s a power failure, the E-Brake has a spring-return mechanism that causes the ram to go up, not down like on the older hydraulic press brake it replaced.

The new SafanDarley E-Brake at the Prototype Development Lab has a built-in light curtain. The light guard provides safety and can be used to operate the ram. SafanDarley.

Those safety enhancements made the press brake a favorite of both the search team and, ultimately, NASA, according to Wells. The commitment to minimizing health risks for personnel begins long before the astronauts are sent into space.

Wells added that the light curtain can be used to operate the brake’s ram, totally bypassing the foot pedal. (Other modes allow the operator to use the foot pedal exclusively or a combination of the foot pedal and interrupting the light curtain.) For example, in one particular mode the operator can wave a hand into the light curtain to advance the ram into the workpiece. As the ram retracts, the operator can move the workpiece for the second beam, which then triggers the ram to advance down again. The process continues in the same manner until completion.

“It’ll really be used a lot for smaller parts,” Wells said. The bending can be done quickly and set up away from the foot pedal, if necessary, depending on how the tooling setup is done.

The tooling is being upgraded with the press brake as well. The PDL is getting Wila press brake tooling, which means the lab is shifting from bottom bending to air bending. That’s going to result in a lot less tooling that the lab has to keep organized, Wells said.

So what does the bending process look like now? The technicians are able to feed 3D models—the engineers use Creo for designing of 3D models and the PDL uses SolidWorks—into the SigmaTEK SigmaBEND software, where they can see how the part actually will bend and with what tooling. Once the bending software produces the bending sequence, the technician can then set up the tooling quickly because the Wila tooling can be front-loaded, not slid in from the side of the press brake into the right place in a holder. The technician can initiate the brake, wait for the backgauge to position itself, and start the bending sequence.

“We all have different things that we need to do around here. I don’t necessarily have a day to set up the press brake and try to get the right bend for one or two parts,” Wells said. “I need to be confident in the software and the press brake so when I punch in the numbers, I can go over to the press brake and bend one part and have it right.”

A New Bend in the Road

Capital Machine Technologies, the distributor that handled the sale and installation of the 80-ton press brake, offered machine and software training to the PDL technicians, and Wells said that got everyone excited about the potential of the new forming tool. They won’t be actively looking to avoid the press brake in 2021.

The new E-Brake was installed in February. Wells said he spent a lot of time at the first of the year preparing for its arrival. He’s glad it’s in place.

“I’m a technician. At the end of the day, I love working on new equipment,” he added.

But that’s only part of it. Wells said that the lab’s capabilities and collective knowledge make it a place that is unlike any other place he’s ever worked, and he noted that he once worked in the research and development area for a jet manufacturer. The work the PDL does is something that few if any other metal fabricators are doing. Wells is glad he gets a chance to be a part of it.