Xometry offers Direct Metal Laser Sintering (DMLS) and Metal Binder Jetting (BJ3D) to 3D print metals using additive manufacturing techniques. Please keep the guidelines below for the tolerances and accuracy of 3D printed metals in mind when designing parts.
- DMLS: +/- 0.001” - 0.006” (+/- 0.0254mm - 0.1524mm) is typical for positive features, and +/- 0.004” - 0.006” (+/- 0.1016mm - 0.1524mm) for negative features such as holes. Build volume of 9” X 6” X 6” (228.6mm X 152.4mm X 152.4mm).
- BJ3D: Shrinkage usually ranges from from 0.8% - 2% during cooling depending on the part’s size and geometry. Internal geometries, such as holes and slots, may shrink by 3 - 5%. Build volume of 29” X 15” X 14.25” (736.6mm X 381mm X 361.95mm).
- DMLS: Overhanging features larger than 45 degrees from vertical require support structures, which may restrict freedom of design. Supported features may have a rougher or uneven surface. Stress, supports, and other geometry considerations may cause deviation in tolerances and flatness. Be sure to utilize fillets as much as possible to help material build naturally. Fine features are more resolved in stainless steel than aluminum due to a lower thermal conductivity so design for looser tolerances in aluminum. DMLS parts tend to have a matte gray or “sugar cube” like finish.
- BJ3D: Thermal shrinkage during the infiltration process is unpredictable and non-uniform. This includes flatness of broad or long parts as well as smaller bridging features. As a general rule, scale up designs by 1.5% to account for shrinkage. Design all features to be over 0.040". Parts are built in a powder bed, so features must allow excess material to clear or utilize exit holes. BJ3D parts tend to have a matte gray-to-bronze finish with external surfaces smoothed via tumbling.