3 Design Considerations Before Prototyping
With fast production and broadened design possibilities, 3D printing has become a go-to for rapid prototyping. Engineers and designers looking to take advantage of 3D printing for prototyping should consider these key considerations before getting started.
Step 1: Determine End-Product Needs
At the forefront of the decisions made for rapid prototyping should be your product’s application.
If your prototype needs to replicate the final product’s cosmetic looks, you may turn to a technology and material that provides a finer resolution, or you may need the prototype to be post-processed for aesthetics.
If you need your prototype to simply function exactly as the end-product will; that is where technologies that offer robust materials and ideal tolerances come into play.
Recommended technologies for final product look:
· Stereolithography (SL)
Recommended technologies for function:
· Fused Deposition Modeling (FDM)
· Direct Metal Laser Sintering (DMLS)
· Laser Sintering (LS)
Step 2: 3D Printing Technology Design Adjustments
Depending on which 3D printing method you use will determine specific design adjustments, like offsets and variances, which may need to be implemented into your CAD file. Our Design Guidelines highlight these important considerations.
PolyJet offers the ability to combine flexible and hard materials, as well as full color and transparencies. Stereolithography (SL) builds detailed parts with the smoothest surface finish. Our proprietary offerings include near-hollow builds for extremely light-weight parts. These two technologies are ideal for concept models and prototypes that need excellent aesthetics.
For functional prototypes, Fused Deposition Modeling (FDM) and Laser Sintering (LS) build strong, durable parts with engineering-grade thermoplastics. Direct Metal Laser Sintering (DMLS) is also available for metal prototypes. Produced much faster than with traditional manufacturing methods, these prototypes provide realistic simulations of the mechanical functions of your design in the same materials as the end product.
Step 3: File Formats and Design Guidelines
3D printing methods use .STL files for set up and builds. While native CAD can be converted to .STL format, issues can arise on occasion when conversions happen outside of the native software. To help ensure a great build, send your CAD in .STL format.
Design Mistakes to Avoid:
· Multiple shells and unshared edges on an .STL file
Multiple shells and unshared edges on an .STL file can cause uneven surfaces that overlap or disconnect from one another. The best .STL files typically only contain one shell and no unshared edges. Files that have multiple shells will most likely not build as desired. It’s also key to indicate what unit of measurement your file was originally designed with, inches or millimeters? Noting original units of measurement can reduce potential errors.
3D printing processes are free-form production systems, allowing for incredibly intricate parts. They are accurate within thousandths of an inch but have lesser tolerance control than some traditional manufacturing methods. Each process has a minimum feature size, varying from .010″-.030″. Designers should account for slight dimensional variance for designs like interference fits and line-to-line designs or plan to utilize CNC machining after builds for critical tolerances.
For more detailed design considerations related to each technology, download our technology Design Guidelines.