March 7, 2018
Elite’s Machining, Automation, and Controls team have been experimenting with 3D printing as an alternative to machined aluminum fixtures. “3D printing” is a type of additive manufacturing that precisely layers plastics, composites, or polymers into a final object, and it is most widely used for rapid prototyping. While aluminum remains the best material choice for most testing applications, it certainly has limitations when complex shapes are involved.
What advantages does 3D printing offer for test and automation systems?
Todd Bruhl, Elite’s lead mechanical designer, set out to answer that question. He has been designing and fabricating aluminum parts and automation systems for more than 10 years and wanted to determine how 3D printed parts matched up. After researching several types of 3D printers, Todd found a desktop system that could produce parts with high-strength materials to withstand harsh test environments and repetitive motion.
As part of a recent Electrical Connector Testing project, Todd investigated both aluminum and 3D-printed holding fixtures for insertion force and torque testing. The results were clear – and they demonstrated the three key advantages of 3D printing:
1. Lower cost to produce
Material and labor are the main costs for traditional machining and 3D printing reduces both. Todd noted that “unlike traditional machining, you only pay for the material you use with 3D printing – none of it ends up as scraps on the floor.” Moreover, the 3D printer uses fewer resources and can operate unattended. For our sample project, the manufacturing cost of the 3D-printed fixture was 97% less than its aluminum counterpart and it weighed 93% less. Most importantly, the 3D-printed fixture demonstrated equivalent performance for our application.
2. Faster delivery
“Creating a solid model in CAD is typically the first step to design a fixture – with 3D printing, that is the only step,” according to Todd. Once created, the solid model is uploaded directly to the 3D printer eliminating the detailed drawings, print reviews, and CNC programming that are necessary for aluminum machining. The 3D printer can also run unattended once it is started to deliver new parts overnight.
3. Tighter tolerances without special tooling or processes
“What made this project unique was the small radius on the inside corner of the through-hole, which required Laser or Waterjet cutting,” Todd explained. Intricate features require specialized tooling and processes to achieve with aluminum – adding significant cost and machining time. Depending on the material, our 3D printer produces precise small-radius corners without any special considerations. Todd also noted that the additive process allows “blind” internal features that would be impossible using traditional machine methods.
3D printing is quickly proving its value at Elite by reducing fixture costs and delivery times for our customers. We are continuing to discover other applications throughout the lab, including low dielectric constant fixtures for EMC testing, low-mass fixtures to facilitate rapid temperature transitions, and complex part interfaces for shock and vibration testing.
This is the latest example of Elite’s drive to apply new technology to help our customers succeed. Our goal is to meet all of our customer’s needs in one location to shorten test schedules, streamline their supply chains, and deliver dependable test results that get their products to market quickly.