by Melissa Donovan
Part 1 of 4
Three-dimensional (3D) printing is used everyday in a number of verticals. One of which is the appliance industry. These manufacturers rely on 3D printing to create prototypes as well as tooling for their production lines. Also, becoming more popular, is the use of additive manufacturing (AM) for spare or replacement parts.
The April issue of Industrial Print magazine includes a feature article on 3D printing for appliance manufacturers. It discusses many of the benefits, challenges that need to be overcome, and popular technologies currently used.
We also held a webinar in March on the topic. If you’d like to view the archived broadcast, 3D Printing for Prototypes and Spare Parts, click here to register.
This article is the first in a series that looks at specific instances were 3D printing was leveraged for appliance manufacturing.
Light and Functional
Handles are an integral part of an appliance with a door or lid. One vendor approached Protech, the distributor of Xact Metal 3D printers in the Sweden, to design a handle from a sketch. The plan was to produce the handle as a prototype and then escalate to a volume of five parts, with the goal of manufacturing up to 100 pieces per year.
The vendor’s goal was for the part to be as light as possible—less than 100 grams—and easy to clean. This meant avoiding designs that included holes and lightweight structures visible on the handle’s outer surface. Protech worked from a sketch to a 3D CAD model using TopSolid’Design, a CAD/CAM system that helps it to achieve the final model in 12 hours.
From there, it CNC programmed in TopSolid’CAM and then cut the handle manually, as well as sandblasted for a smooth surface finish. The final part in aluminum weighed 187.5 grams. It took a total of eight hours from machining the handle via CNC processing, which included tool setup and reprogramming, since it was the first pass. The second run took one hour and 25 minutes.
While the time it took to produce when down significantly in the second run, and would decrease further in subsequent runs, Protech debated if it could achieve more efficiencies by changing how the handle was manufactured. In addition, the handle weighed far too much based on the vendor’s goals.
Protech turned to AM to make a hollow, stainless steel part. The mechanical and precision criteria on the attachment end of the handle required Protech to keep that part of the handle in metal, but not limited to aluminum. So, it chose to work with 316L Stainless Steel.
The original handle design was hollowed out with a wall thickness of one millimeter and a small hole added to drain 316L Stainless Steel powder out of the hollow handle. It printed the hollow handle in its Xact Metal, Inc. XM200C—a metal powder bed fusion device. Occurring in 43 hours and 11 minutes, the build allowed for one handle at a time. The final piece weighed 112.2 grams, closer to the target weight than previous tries.
Weight was still a challenge, as was efficiency—one part in 43 hours wasn’t ideal. To address the former, Protech needed to reduce the handle’s metal content without changing the design. The attachment part of the handle required metal, but the other part—the lever—did not. So, the Protech team decided to produce the handle in a combination of metal and plastic in two parts that would be fitted together after production.
The lever was printed in the Stratasys Fortus 450mc 3D printer using Nylon 12 Carbon Fiber. Ten lever parts fit into one build and printed in seven hours and 36 minutes. The lever weighed 25 grams.
The attachment part was printed in the Xact Metal XM200C using 316L Stainless Steel. It was designed with both print cost and support removal time in mind. It was packed efficiently on the print platform, hollow, and had few supports to remove. Ten attachment parts were fit into one build and printed in 125 hours and ten minutes.
Once assembled, the two-part handle weighed 85 grams—coming in below the intended 100 gram mark.
Goals Met
Protech used trial and error to understand and ultimately achieve the goals of its vendor partner. Thanks to 3D printing and smart thinking, it was able to create a lightweight handle.
May2021, Industrial Print Magazine