A machinist overseeing the 3D printing process is setting up the machine for a new build. After purging the chamber and setting the oxygen level, he is ready to set the plate build height of the VELO3D Sapphire 3D printer. (Wagner Machine photo)

Wagner Machine complements an innovative 3D printing system with comprehensive post-machining capabilities. For designers, the key is to plan 3D printing with finish machining in mind.

 By Mark Langlois

Kurt Wagner, CEO of Wagner Machine Company, thought about metal 3D printing for 25 years after seeing his first 3D metal printer in 1996 at a Chicago trade show. He didn’t like it. It was unreliable.

“It was so complicated and inconsistent and difficult to use that you could hardly imagine an application for it,” said Wagner in a phone interview. “I thought it would never catch on. We’ve been following it ever since then. It’s awesome to see some of the changes and a lot of the changes that recently have been made.”

After finishing high school in 1998, he started machining in the family CNC machine shop, making production mill and lathe parts. Wagner Machine Company, founded by Wagner’s parents in 1982, grew a reputation in Champaign, Illinois, for the ability to make impossible parts with its 5-axis mills, Swiss turning, CNC milling, wire EDM, and prototyping capabilities. The company  earned ISO 9001 and AS9100D quality certifications, and it employs 51 people at its 33,000-square-foot factory.

Much of Wagner Machine’s early work focused on making small- to medium-sized repair parts for local businesses in quantities from one to several thousand parts. Sometimes university researchers and startup companies stopped by with one-off prototypes. Today the company works in aerospace, defense, oil and gas, agriculture, and for university researchers across the country. Wagner Machine’s capabilities grew with the technology that kept improving and evolving. It can provide tolerances as tight as 0.0002-inch, depending on the materials and design. By using automation, it can provide production quantities of more than 100,000 parts, Wagner said.

“Our problem-solving creativity is focused on how to make a part the way our customer wants it,” Wagner said, adding that Wagner Machine is a specialist in design for manufacturing. The company tries to adapt and improve its manufacturing process to meet the customer’s needs, rather than redesign the customer’s part to meet Wagner’s ability. “When everyone else says it can’t be done, people come to us,” Wagner said in a release.

Researching and Learning the Ropes

Wagner kept up with advances in metal 3D printing and was looking for a 3D metal printing system that would complement Wagner Machine’s advanced machining capabilities. His move into 3D metal printing came after VELO3D introduced the VELO3D Sapphire® printer with Flow™ print preparation software and Assure™ quality assurance software. The machine uses a laser powder bed fusion process and prints F357 aluminum.

Wagner took a team of employees to VELO3D in Campbell, California, during the pandemic to see the new VELO3D equipment. He said he was always drawn to 3D printing as a step toward creating “impossible” parts, but it didn’t seem complete without the addition of CNC machining.  Wagner’s desire to make impossible parts aligned directly with VELO3D CEO Benny Buller’s desire to “build the impossible.” After meeting Buller, Wagner knew it was the metal 3D printing technology he had been waiting for.

Big manufacturers have been using metal additive manufacturing for a long time, but Wagner said he still thinks he’s an early adopter. He’s happy with the outcome, especially for prototype and low volume production. Originally, Wagner figured he’d have to either hire someone with a Ph.D. in metallurgy or partner with a local college’s material sciences department to figure out 3D printing. That’s what other technology seemed to require. With VELO3D, the metallurgy and process is already figured out, and he has been able to train existing employees to calibrate and run the machine.

The VELO3D Sapphire printer drastically reduce the number of supports required to print a part, lessening the need for post processing. Although supports are still required in some situations and can help reduce build time in others, they can be reduced or even eliminated in critical areas, Wagner said.

 Wagner Machine is learning how to use the new Flow software, which intelligently assigns the print processes to the part from a library of specialized recipes. Wagner said the Flow software is so good, it’s almost boring. It sets all the parameters for the lasing process, he said, because the material has been tested and approved by VELO3D.

This photo of the printer laser melting the powder on the VELO3D Sapphire printer is taken while printing small impellers made from F357 aluminum. The narrow profile and varying pitch of the blades made this an excellent test for the thin wall and low overhang printing capabilities of the printer. To speed up the process, Wagner added supports to key areas, but much of the part is unsupported at low overhang angles. (Wagner Machine photo)

“Before importing into Flow, we adjust the customer model to account for post machining. This is an extremely important step that we work on with input from our customer,” Wagner said. “Looking at the whole manufacturing process from the beginning ensures we can get the part right the first time. Once we import the models into Flow, we can add supports and define special processes if we think they are necessary.”

Most of the time, Flow automatically selects the correct process based on part geometry. But it also offers flexibility for users to make adjustments, Wagner said.

“The software isn’t hard to use, but there are a lot of options, so we’re having VELO3D double-check us on it. They have a whole team of applications engineers who have been very helpful, and we learn something new on almost every build.”

Didn’t Know It Was Impossible

The VELO3D Sapphire printer and Flow software enable Wagner Machine to make parts with low angles, thin walls, and walls that funnel inward, as well as walls that funnel outward. Those features have no supports to be cleared away in a secondary operation, said VELO3D Vice President Zach Murphree, Ph.D., in a phone interview.

Murphree arrived at the company when it had fewer than 30 employees. It didn’t make 3D printers. So how is it that VELO3D software and hardware overcame the need for supports?

“The solution is a combination of software, hardware, and the process. The approach was to figure out how to measure everything we possibly can, so we can make these systems do more than anyone else can make them do,” Murphree said. “When I joined VELO, nobody had any experience with AM. They didn’t know what the industry said couldn’t be done. So they just did it.”

While working with VELO3D as the vice president of technical partnerships, Murphree designed next-generation hardware and software by working with customers and industry on commercialization and partnerships. He said one of his goals is to help customers design the no-compromise part.

In the past, design engineers sometimes compromised their designs because the machining and 3D printing equipment couldn’t make the part they wanted.

“A lot of people we work with are very competent and well-respected precision CNC shops. Part of the issue is that they were running across parts and opportunities that were a little beyond what they wanted to take on with more traditional manufacturing techniques,” Murphree said.

As an example, Murphree said in some turbo pumps, engineers designing the volute on a centrifugal pump might compromise their design. Instead of a round channel—the optimal shape—to carry a liquid or gas from the impeller to the exhaust port, designers would make it tear-shaped because that was manufacturable with conventional additive manufacturing.

“That’s not the right shape for that component. It causes a stress concentration at the point of the tear drop,” Murphree said. “If it’s pressurized inside, it will try to open up there, so engineers compromise by adding more material and, therefore, weight. VELO3D can print the original geometry without the tear drop, meaning no compromise. We can print internal geometries without supports. It [VELO3D] really allows the design engineer to fully optimize the part for any given application.” That caught Wagner’s eye.

Many of the parts Murphree talks about are components with complex internal geometries. These parts are used in numerous industries, including aerospace, oil and gas, drones, renewable energy, and others. The old challenge was how to remove supports from the interior of a part once it’s printed. With builds that are support-free, that obstacle is overcome, Wagner said.

The VELO3D printer works on high-value aerospace parts, such as microturbines, turbo pumps, impellers, valves, manifolds, and heat exchangers. “Complex internal passages are at the core of what we do,” Murphree said.

Murphree said one of VELO3D’s goals is to tailor the 3D process to produce the desired characteristics in the material the customer wants. Wagner is printing F357 aluminum. Teams of scientists and engineers at VELO3D work on optimizing the mechanical properties of the materials, while at the same time designing the software, hardware, and manufacturing processes that use those materials to make parts.

“When you’re first developing an alloy, it may not meet the end requirements. That has to do with the mechanical properties—it could be due to the cooling rates, how liquid turns to solid. You can end up with a microstructure that is different from what was intended,” Murphree said.

“At the most fundamental level, we’re a process company. We tailor the printing process to optimize it,” he continued. “You can change the mechanical properties by moving your laser more quickly or making the spot you’re melting bigger or smaller. That affects the cooling rate, the thermal history of the part, and the temperature the metal has seen.  The machines are designed to do that, and it can directly affect the mechanical properties coming out of the machine.”

Machining Plus 3D Printing

Wagner saw the beginning of a business case when customers started bringing in 3D printed parts that needed finish machining. By combining 3D printing and machining in house, Wagner figured he could help customers improve the functionality of their products in ways they had never imagined, while streamlining the whole process.

“One of the things that isn’t talked about is most additive parts, especially metal parts, require some kind of finish machining process. If the whole process isn’t considered from the beginning, a lot of times you’ll get a printed part that can’t be finished for a variety of reasons,” Wagner said.

Wagner illustrated his point with a $20,000 Inconel 718 aerospace part that a customer sent for finish machining. The 3D printed blank was approximately 12 inches in diameter and 18 inches long, with thin walls.

“It was pretty big as a 3D part goes,” he said. “They were trying to save weight on it and add internal channels for pressure and temperature monitoring. It was a great part for 3D printing, but the machining hadn’t been taken into account.

“One end was supposed to be flat from where the part was cut off the plate with a wire EDM,” he continued. “Unfortunately, the part was printed upside down from what our customer intended, so that side was up. As printed, that surface wasn’t flat enough to seal, but no additional material had been left to finish machine it. In addition, when they cut the other end off of the build plate, they cut it off on the short end of the tolerance, which left no room to get most-machined features in spec.”

Wagner was blown away that its customer seemed okay with all the issues and the extra cost.

“That is what people have become accustomed to with metal 3D printing, and it’s just wrong,” he said. “A little bit of planning at the beginning can save thousands or even tens of thousands of dollars and months of wasted time.”

Plan Ahead

By failing to plan for the finish machining, the 3D printing firm printed the same part twice, and got paid twice to make one good part. Wagner asked if the customer wanted him to send the original back, and the answer was no. The Inconel mistake sits in a room at Wagner Machine as a reminder to plan 3D printing with finish machining in mind.

In addition to planning for machining by adding more material to key features, a second thing to consider is how the 3D printed part will be fixtured for machining. “Since we are 3D printing the part, it is often possible to build the fixturing right into the print,” Wagner said. “We can add some features to make it easy to hold onto for machining, and remove those in a simple final op after the critical machining has been completed. It has to be considered as a complete process. It’s all part of the same manufacturing process. If you don’t take all the pieces into account in the beginning, you can waste a lot of time or get into a big mess.”

Wagner said the VELO3D Sapphire printer can print parts that other 3D printers can’t.

As one example, a customer called on Wagner Machine with designs for an assembly that required brazing many components together. Because of space  and performance constraints, Wagner said it was impossible to manufacture as designed, and the Wagner team suggested the customer 3D print it. The customer explained he tried that first, but other 3D printing firms had  looked at the design and said the part couldn’t be printed because of tall, thin wall features that were unsupported at one end and had to be airtight. That is why the customer had redesigned the part as an assembly for conventional machining. After discussing design requirements, Wagner was able to convince its customer to go back to the 3D printing design it had started with originally.

“VELO3D was able to print the assembly in a single piece on a VELO3D Sapphire®, and it met all the customer’s performance requirements,” Wagner said in a VELO3D press release. “VELO3D’s real-time monitoring of the 3D printing process from start to finish with their integrated Assure™ quality assurance software is exactly what metal AM needs to be ready for prime time.”

The Assure quality control software monitors each 3D printed part as it is being printed, layer by layer. In addition to offering pre-build system calibration, Assure offers users the ability to monitor part quality and critical process variables in real-time. The automated build reporting functionality built into Assure offers full traceability of system performance and highlights risk areas, Wagner said. He added that the Assure software gives him confidence in his 3D printed parts “without wasting tons of time looking at raw data.”

“Nobody wants to look at thousands of layers of height map data, machine conditions, and images,” he said. “You can easily look at a specific layer that has a build issue because it is flagged by the software.”

Before the machine could be delivered, Wagner Machine sent parts to VELO3D directly to manufacture, giving Wagner experience in reading and understanding the real-time monitoring reports created by the VELO3D Assure software.

Wagner said VELO3D made 24 parts in Campbell for Wagner Machine in two builds of 12. Four parts in one build were flagged with potential issues. The quality review found the four parts did have flaws in critical areas and could not be used as production parts.

“Because the Assure software was able to show us exactly where the issues were, we were able to accept the other eight parts,” he said. “We used the four bad parts as set-up for post machining and to test coatings, and ended up with exactly 20 good parts for our customer. Without Assure, we might have never known there was an issue, or we would have had to scrap the full build of 12 parts. This advanced monitoring capability saved us a whole extra build.”

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