Built Up: Medical Manufacturing

Part manufacturers with machine shops have advantages compared to other manufacturers when incorporating additive manufacturing (AM), or 3D printing, to their capabilities for producing metal parts, according to Joel Sam, metals business development manager for EOS North America. That’s because job shops typically have CNC machine tools, including wire EDMs and bandsaws, as well as cutting tools and post-processing equipment such as media blasting that complement metal AM.

“This is why I always say that machine shops have a leg up when it comes to getting into metal 3D printing. Other customers who don’t already have that equipment – it’s a lot bigger ask.” Sam said. “With plastic printing, sometimes you can just take it out of the printer and you’re ready to go, but with laser powder bed fusion, you have to product separate the metal from the build plate, so you need a wire EDM or bandsaw to do that.”

EOS reports that the M 300-4 platform provides flexible automation options, allowing customers to optimize their workflow and scale up as demand increases. EOS

Sam also noted that the surface finish of printed metal parts is generally a bit rough and must be finished on a CNC machine or with a secondary process. That requirement is particularly important when, for example, there is a sealing surface or a feature that requires tight concentricity.

EOS North America has regional offices at its technical centers in Novi, Michigan, and Pflugerville, Texas, and offers laser powder bed fusion, or Direct Metal Laser Solidification (DMLS), technology for 3D printing metal parts, selective laser sintering technology for plastic 3D printing, and materials for both technologies.

Nonetheless, machine shops must overcome a couple of key barriers to successfully implement metal AM, Sam said. The first is expertise. Shops, such as contract manufacturers, employ workers with a range of machining skills, such as knowing the proper speeds and feeds needed for a job, understanding how to read blueprints, and performing CAD/CAM programming. AM, however, requires new skills, such as using 3D printing- specific software.

For example, EOS offers EOSPRINT software that, according to the company, allows end users to assign and optimize process parameters for industrial 3D printing on EOS systems. It calculates the exact path of the laser in the production process to optimize build speed and part quality.

A cross section of an aluminum heat exchanger produced with EOS laser powder bed fusion equipment. EOS

“If you just have an STL file, which historically has been the standard 3D printing file,” Sam said, “you can drop it into EOSPRINT directly and print it if it’s completely printable.”

EOS continually strives to make its software more intuitive, Sam added, because safety is the main way that operators interact with the print on the front end. Traditional manufacturing software, such as CAD/CAM, is developed with conventional machining in mind, but new software is required for topology optimization and other AM-specific design processes.

Artificial intelligence is also entering the AM design picture to boost efficiency, he noted. “You enter in your limits or your design points, and the computer can do the work for you.”

Gaining Knowledge

Metal AM education and training for shop staff is critical for efficiently and profitably printing parts, Sam added. EOS has a training team based at its Metro Detroit Additive Minds Academy Center that travels to customer sites and shows operators how to use EOS technology. In addition, Sam emphasized the need for end users to comprehend the design-for-manufacturing principle, which is covered in an online course he teaches as part of the EOS Additive Minds Academy. The course also covers the types of geometries that are buildable – or not buildable – and the impact that changing laser parameters has on the build process.

The Additive Minds Academy, the EOS workforce development and education arm, provides comprehensive training programs for AM education, onboarding, upskilling and reskilling. The academy also offers continuous learning opportunities for companies using EOS technology.

Laser powder bed fusion machines from EOS are suitable to produce this impeller made of a nickel-base alloy. EOS

Even companies without an AM machine can visit an EOS training center for guidance on the process, the necessary software and machine operation. The training and education enable manufacturers to build on the technical aptitude that their machining personnel already have for mechanical and manufacturing engineering.

Sam emphasized the need for more specialized AM training in the industry, noting “that’s what we’re trying to do [with] that online content and in-person training.”

Another barrier to AM adoption, Sam added, is the relatively high cost of the equipment. Industrial 3D printers are a sizeable investment, with varying prices dependent on factors such as platform type, laser power, build volume and customization needs.

On top of the price is the trial and error required to learn a new technology. “When you’re building parts for a customer, you typically want to have first-time success,” Sam said, “and with 3D printing, if you’re new to it, it’s going to take a few tries to figure it out.”

A machine shop could outsource 3D printing to a service bureau, Sam noted, adding that he worked for a bureau before joining EOS that had 17 EOS machines, as well as in-house CNC machining, heat treatment and a coordinate measuring machine and surface profile scanner. Bringing AM in-house can be done in “baby steps,” starting with one piece of equipment and expanding as expertise and business grows.

Controlling Quality

Although the majority of metal part manufacturers already have a quality control (QC) department, they might have to learn new QC techniques that are more unique to additive, Sam said. For instance, destructive tensile testing is familiar in conventional manufacturing where a controlled tension is applied to a sample until it fully fails. A metal AM part, on the other hand, might require optical microscopy to ensure that there are no pores in a print. “If something goes wrong with the laser parameters for some reason, or the parameters aren’t optimized, you’re going to see porosity.”