Modern Machine Shop and MoldMaking Technology present ADDITIVE MANUFACTURING, a quarterly supplement reporting on the use of additive processes to manufacture functional parts. More at additivemanufacturinginsight.com.
Issue link: https://am.epubxp.com/i/542042
16 — AM Supplement F E A T U R E Best Practices in AM Design According to Faustson VP Heidi Hostetter, users of additive manufacturing technology are key to its fu- ture development, because developers will listen to them to learn what improvements are still needed. Users also become the best teachers, which falls in line with Faustson's mission of being a resource for others and promoting the next step in the maturation of metal additive manufacturing. It is with this goal in mind that Hostetter shares some lessons learned in AM design: • Review support structures closely. Supports most likely belong on critical surface-fnish locations. • Holes from horizontal to 45 or 50 degrees to the build platform should be no larger than 6 mm in diameter to minimize post machining. Larger holes may require internal supports and/or post machining. • Roundness is tough to achieve with holes from horizontal to 45-50 degrees. Dome or spherical shapes are easier to achieve. • Material layers are typically approximately 30 microns in thickness. • Wall thickness typically should be greater than 380 microns depending on material. This thickness is the most aggressively thin wall permissible at this time due to melt pool size. • It is good practice to require a Parasolid fle and then convert and alter the STL prior to slice con- version. The optimal STL fle can be generated by the shop (the AM user) to control resolution These parts, still on the build plate, show the support structures still intact. . for better fnishes and minimize the "fxing" re- quired to create clean geometry. • Supports will serve as a heat sink, and this should be considered during part design. • Multiple parts, complicated assemblies or match-machining are all good fts for additive technology. • The Z axis will always be a source of potential part weakness. The grain is in the X-Y axis. However, post process heat treat will elimi- nate most of this difference. • Angles are your friend. Think 45 degrees and steeper, as these do not require supports. An- gles less than this have rougher surface fnish and may require secondary processing. Although the many benefts of AM are well- known—increased part strength, reduced part weight, the ability to create complicated fea- tures, no assembly required—many of the AM pioneers who have successfully realized those benefts do not share their experiences, or their formula for success. "We decided that if we get into this, we must act as a resource for oth- ers, promoting the next step in the maturation of the additive metals industry," she says. For example, Faustson has reached agreements with customer Ball Aerospace & Technologies of Boulder, Colorado, to disclose its experiences where propriety isn't violated. The machine shop also brought in Marshall Space Flight Center staff members to meet with Ball Aero- space and another customer, Woodward Inc. of Fort Collins, Colorado, to relate their experi- ences with using the technology. In other words, Faustson facilitates information- sharing within its corner of the manufacturing industry as much as it can. In fact, the company believes industry needs someone specifcally in contract manufacturing to champion AM as a re- source for making products better. Faustson does not produce its own products, it manufactures its customers' products, so the shop pushes the tech- nology for the beneft of its customers. Faustson aims to produce not only parts but also processes for customers, then share what it has learned