3D Printing Design Guidelines: Complete Technical Reference for All Technologies

Success in 3D printing depends heavily on understanding the capabilities and limitations of each technology. This comprehensive guide provides detailed technical specifications, design constraints, and best practices for FDM, SLA, SLS, DMLS, and PolyJet technologies to ensure your parts print successfully and meet performance requirements.

Proper design consideration during CAD modeling ensures successful 3D printing across all technologies

Design for Additive Manufacturing (DfAM) Overview

Design for Additive Manufacturing (DfAM) requires understanding how each technology builds parts layer by layer. Unlike traditional subtractive manufacturing, 3D printing enables complex geometries but introduces unique constraints around support requirements, surface orientation, and material properties.

Universal Design Principles

• Water-tight Models: CAD files must have no holes, overlapping geometry, or incorrectly oriented normals
• Support Considerations: Design parts to minimize support material requirements where possible
• Orientation Optimization: Consider how part orientation affects strength, surface finish, and support needs
• Feature Sizing: Respect minimum feature sizes and wall thickness requirements for each technology
• Clearances: Account for technology-specific clearances for moving parts and assemblies

FDM

SLA

SLS

DMLS

PolyJet

FDM (Fused Deposition Modeling) Guidelines

FDM technology builds parts by extruding heated thermoplastic filament layer by layer. Our Fortus series printers offer soluble support materials and exceptional accuracy for production-grade applications.

FDM Design Considerations

• Visible Layer Lines: FDM parts show layer lines, especially on curved surfaces
• Sparse vs Solid Fill: Choose based on strength requirements and material cost considerations
• Drain Holes: Required for hollow parts to remove soluble support material
• Orientation Impact: Circular holes may become oval; drill oversized holes if precision required

SLA (Stereolithography) Guidelines

Stereolithography uses UV lasers to cure liquid photopolymer resin, producing parts with exceptional surface finish and fine detail capabilities.

SLA Critical Design Points

• Hollow Parts: Must include large drain holes to prevent resin expansion damage
• Support Requirements: Overhangs and islands require support structures
• Surface Finish: Build orientation affects surface quality on different faces
• Post-Processing: Parts require washing and UV curing after printing

SLS/MJF (Powder Bed Fusion) Guidelines

Selective Laser Sintering and Multi Jet Fusion use powder bed fusion to create strong, functional parts without support structures.

DMLS (Direct Metal Laser Sintering) Guidelines

DMLS technology produces functional metal parts with complex internal geometries impossible to machine conventionally.

DMLS Design Considerations

• Support Structures: Required for overhangs, anchoring, and heat dissipation
• Stress Relief: Heat treatment may be required for stress relief
• Machining Allowance: Add material for post-machining critical features
• Build Orientation: Affects surface finish and mechanical properties

PolyJet Multi-Material Guidelines

PolyJet technology enables multi-material and multi-color printing with exceptional detail and smooth surface finishes.

PolyJet Special Considerations

• VeroClear Transparency: Can achieve optical clarity with post-polishing
• Support Material: Water-soluble gel support requires large access holes for removal
• Fragile Features: Thin features may break during high-pressure cleaning
• Multi-Material Boundaries: Plan material transitions carefully for strength

Technology Comparison Table

Industry Applications

Aerospace Applications

Aerospace components require precision, strength, and often complex internal geometries. DMLS excels for metal brackets and heat exchangers, while SLA provides detailed scale models and wind tunnel prototypes.

Automotive Prototyping

Automotive applications span from concept models to functional testing. FDM provides durable test fixtures, SLS creates end-use interior components, and PolyJet delivers realistic appearance prototypes.

Medical Device Development

Medical applications demand biocompatible materials and precise fits. SLA clear resins enable surgical guides, while specialized biocompatible materials are available for patient-specific applications.

File Preparation and Quality Standards

CAD Model Requirements

Successful 3D printing begins with properly prepared CAD models. All technologies require water-tight meshes with correctly oriented surface normals.

• File Formats: STL, OBJ, or 3MF files preferred
• Resolution: Export with sufficient triangle density for curved surfaces
• Units: Clearly specify units (mm recommended)
• Scale Verification: Double-check model scale before submission
• Feature Check: Verify all features meet minimum size requirements

Quality Assurance Process

Our production team reviews all files for printability before production begins. However, customers are responsible for ensuring designs meet the technical requirements outlined in these guidelines.

Conclusion: Designing for Success

Understanding the capabilities and limitations of each 3D printing technology is essential for successful project outcomes. These guidelines provide the technical foundation for design decisions, but successful implementation also requires considering material properties, post-processing requirements, and end-use applications.

Whether you're developing prototypes, production tools, or end-use parts, following these design guidelines will help ensure your 3D printed components meet performance requirements while minimizing the risk of print failures or post-processing issues.

Additional Resources

• 3D Printing Technologies Overview
• Technology-Specific Design Guides
• Material Properties Database
• Get Instant Quote for Your Design