Why Design Rules Matter in Additive Manufacturing

Industrial 3D printing offers incredible design freedom. But that freedom comes with responsibility. Ignoring key 3D printing design rules leads to weak parts, failed builds, and wasted budgets.

Additive manufacturing company Slant 3D recently outlined seven critical mistakes engineers make. These errors compromise part strength and reliability. Understanding them helps you design better parts from the start.

Whether you’re prototyping or producing end-use components, these principles apply. Let’s examine each rule and how to avoid costly mistakes.

Rule 1: Never Ignore Layer Orientation

3D printed parts have directional strength properties. Layers bond together during printing. But that bond is weaker than the material itself.

Parts loaded perpendicular to layers fail more easily. Always consider print orientation during design. Orient critical load paths along the strongest axis.

Rule 2: Avoid Stress Concentrations

Sharp corners create stress risers in any material. In 3D printed parts, these become failure points. The layer structure amplifies the problem.

Use fillets and radii wherever possible. Even small chamfers improve part durability significantly. This applies to both internal and external features.

Rule 3: Design Appropriate Wall Thickness

Walls that are too thin cause print failures. They also create weak, fragile parts. But excessively thick walls waste material and time.

Consider these wall thickness guidelines:

  • Minimum 1.5mm for functional SLS parts
  • Minimum 1.0mm for resin printing
  • Add ribs instead of increasing overall thickness
  • Hollow large volumes with proper drain holes

Rule 4: Account for Thermal Effects

Additive manufacturing involves heat. Parts cool unevenly during and after printing. This creates warping and internal stresses.

Large flat surfaces are particularly problematic. They curl and distort as layers cool. Design features that break up flat areas reduce these effects.

Tips to Minimize Warping

Add ribs or textures to large flat surfaces. Avoid sudden thickness changes. Work with your manufacturing partner to optimize orientation.

Rule 5: Respect Minimum Feature Sizes

Every 3D printing process has resolution limits. Small holes may close up during printing. Fine details may not resolve properly.

Typical minimum feature guidelines:

  • Holes under 1mm often need post-drilling
  • Text should be at least 2mm tall
  • Embossed features need minimum 0.5mm depth
  • Thin pins under 1mm are fragile

Review your process-specific design guidelines before finalizing parts.

Rule 6: Design for Support Removal

Some features require support structures. Removing supports adds cost and time. It can also damage surface finish.

Design self-supporting features when possible. Use 45-degree overhangs maximum. Ensure support areas remain accessible for post-processing. Learn more about designing without supports.

Rule 7: Consider Post-Processing Requirements

Raw 3D printed parts rarely ship directly. They need cleaning, finishing, or assembly. Design must accommodate these steps.

Leave clearance for machining critical surfaces. Plan for media blasting access. Consider how parts will be fixtured during finishing.

Applying These Rules to Your Projects

These 3D printing design rules aren’t restrictions. They’re guidelines for success. Following them produces stronger, more reliable parts.

JawsTec engineers review every project for manufacturability. We identify potential issues before production begins. This saves time and reduces iteration cycles.

Ready to optimize your designs for additive manufacturing? Request a quote and get expert feedback on your parts today.


Sources

Source: The Seven Deadly Sins of 3D Printing by Slant 3D (YouTube) — https://www.youtube.com/watch?v=iiCsQIN_PyQ