Fused Deposition Modeling (FDM) Design Guidelines
The following tutorial is a good starting point to understanding design considerations when 3D printing with Fused Deposition Modeling (FDM). FDM is an additive manufacturing technology that extrudes thin layers of thermoplastic layer by layer until a part is completed. FDM produces robust production parts in engineer-grade thermoplastic, with the added benefits of speed and design freedom possible with 3D printing. The cutting-edge technology is utilized across industries like aerospace, energy and transportation for production components.
Step 1: FDM Design Considerations
The following information builds from conventional plastic part design to explain design considerations for manufacturing high-quality FDM parts.
Step 2: Shrinkage
Stratasys Direct Manufacturing automatically adds shrink rates to the part when processed, so shrink factors do not have to be designed in. Default values can also be adjusted to fit specific geometries when large production runs of similar part designs are needed.
Step 3: Wall Thickness
Minimum wall thickness for FDM parts varies depending upon the slice thickness that will be used to build the part.
These wall thickness figures (above) are a single contour width. Note: building multiple layers while using the minimum contour width will cause the feature to be brittle. (Note that warping may occur if there are large extents of minimum–thickness, vertical walls without support features like ribs, or a support material tower.)
Stratasys Direct Manufacturing encourages the use of the recommended minimum wall thickness (below), which will eliminate brittleness.
Step 4: Finishing and Secondary Operations
Since the FDM process uses engineering-grade thermoplastics, the parts produced are capable of withstanding a number of post-manufacturing processes, including machining operations such as drilling and tapping, sawing, turning, and milling.Other post processing operations may include smoothing, burnishing, sealing, joining, bonding, and plating.
For full details on how to design for Fused Deposition Modeling, download the comprehensive design guide at StratasysDirect.com.