3D Product Design for Additive Manufacturing 3

Question 1

What are the best practices for designing readable text or logos on an FDM printed part?

Accepted Answer

Emboss or engrave text at least 0.5–1mm deep or high using simple, bold sans-serif fonts

Answer

Text thinner than 0.5–1mm often fails to print or lacks legibility; bold sans-serif fonts at adequate relief ensure the features resolve correctly and remain readable.

Question 2

What is 'self-supporting geometry' as a DfAM design principle?

Accepted Answer

Designing geometry that stays within printable overhang limits so no support structures are needed during printing

Answer

Self-supporting geometry uses design rules such as keeping overhangs within 45°, using arches, teardrops for holes, and chamfers to eliminate support material entirely.

Question 3

Why are chamfers on bottom edges of FDM parts often preferred over fillets in DfAM?

Accepted Answer

Chamfers reduce the elephant's foot effect and do not require support material unlike bottom fillets

Answer

Bottom fillets create an unsupported curved surface requiring support material, whereas chamfers replace that curve with a flat angled face that is self-supporting and also reduces first-layer spread (elephant's foot).

Question 4

Why is mesh integrity (no non-manifold geometry or gaps) critical when preparing an STL or 3MF file for functional parts?

Accepted Answer

Slicers require a watertight mesh to compute valid toolpaths; gaps cause print failures or missing geometry

Answer

Slicing software needs a fully closed, watertight mesh to correctly determine inside versus outside and generate accurate toolpaths; any gaps or non-manifold edges can cause missing walls or failed prints.

Question 5

What clearance is typically recommended between mating FDM printed parts in an assembly to ensure proper fit?

Accepted Answer

0.2–0.5mm per side to account for FDM dimensional tolerances

Answer

FDM tolerances are typically ±0.2–0.5mm, so designing 0.2–0.5mm clearance per mating surface ensures parts fit together after printing without requiring significant post-processing.

3D Product Practice Test

3D Product Practice Test

3D Product Design for Additive Manufacturing 3