3D Product Design for Additive Manufacturing 2

Question 1

When designing holes for press-fit inserts in an FDM part, what is the recommended approach?

Accepted Answer

Design holes 0.1–0.2mm undersized, then drill or ream to final size

Answer

FDM holes tend to print slightly undersized due to material shrinkage and layer geometry; designing them slightly undersized and finishing to size yields the most accurate press fits.

Question 2

What is the primary engineering benefit of incorporating lattice structures into a 3D printed product?

Accepted Answer

Significantly reducing mass while maintaining structural stiffness

Answer

Lattice structures are open-cell frameworks that remove bulk material from low-stress regions, dramatically reducing weight while preserving the structural integrity demanded by the application.

Question 3

When designing snap-fit joints for FDM printed parts, which material property pair is most critical?

Accepted Answer

Flexural modulus and elongation at break

Answer

Snap fits must deflect under load (requiring low flexural modulus) and return without fracturing (requiring high elongation at break), making these two properties decisive for reliable snap joints.

Question 4

What does 'functional integration' mean in Design for Additive Manufacturing?

Accepted Answer

Consolidating multiple traditionally separate components into a single printed part

Answer

Functional integration leverages additive manufacturing's geometric freedom to merge several parts into one, reducing part count, assembly time, and potential failure points.

Question 5

Why must designers account for anisotropic mechanical properties when creating press-fit assemblies with FDM parts?

Accepted Answer

FDM parts are stronger in XY than along Z, so fit forces in the build direction may cause layer delamination

Answer

FDM parts are weakest in the Z (layer stacking) direction due to incomplete inter-layer bonding; interference fits that apply stress along Z risk delamination failure.

3D Product Practice Test

3D Product Practice Test

3D Product Design for Additive Manufacturing 2