Wohlers Associates, a 3D printing consulting firm in Fort Collins, Colorado that has provided market, strategic, and technical advice to AM professionals for over 30 years, recently released Wohlers Report 2019, the 24th consecutive edition of the annual report. In it, detailed input of 127 3D printing service providers from around the world was used to determine that approximately 26% of a part’s cost is related to post-processing, such support material removal.
For most people that work with 3D printing, post-processing is almost entirely concerned with removing support pillars, followed perhaps by a bit of sanding. That’s because most people still work with FDM (fused deposition modeling) 3D printers. But there are other post-processing steps for other AM technologies, including powder removal, chemical and pressure treatments, thermal stress relief, UV curing, tapping and milling, and inspection.
Designing for Success
The cost and time required to print a part are largely determined by mass and shape, but when support pillars are considered, orientation can also greatly affect printed mass. The same part could require 20% less material by flipping it on its side due to the geometry of overhangs. However, the design of a part is when its shape is ultimately determined, meaning designers have the most control over the cost of a part. As such, designers need to be intimately familiar with the operation of the specific 3D printing technology they’ll be using to make their part. Anyone who has designed parts that were to be printed on an FDM machine will tell you that you never design a part in such a way that it will experience stress on the Z axis as that’s the weakest axis of any FDM print due to the nature of layer bonding. For instance, a wrench printed in the vertical direction would surely break upon use, but a wrench printed flat on the bed will be incredibly strong.
Similarly, those who design 3D printed parts for FDM machines are always thinking about overhangs that will need support pillars, specifically, how to avoid them. Sometimes adding an angled edge under an overhang is enough to eliminate the need for supports. An arch is also significantly easier to print than a flat bridge across two points. But when a part is designed without 3D printing in mind, it ends up costing more to print and requires more post-processing. So it’s important that designers be educated on the best practices of designing for 3D printing.
Educating for the Future
The economic impact of design on 3D printed parts is significant and there’s currently a shortage of workforce experience in AM, so Wohlers is expanding its hands-on DfAM (Design for Additive Manufacturing) training program with two additional courses. One will be in Austin, Texas on August 14-16, 2019 in connection with the 30th Annual Solid Freeform Fabrication Symposium and the other will be a Design at Elevation DfAM course in Frisco, Colorado on September 11-13. Participants will learn design techniques to improve the economics and performance of their 3D printed parts.