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

Use thin serif fonts at 0.1mm depth for fine detail

Answer

Place text on overhanging surfaces for best visibility

Answer

Use fine detail fonts and print at the smallest layer height available

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

Designing a part that can stand upright on its own without a fixture during use

Answer

Creating a part that self-repairs if cracked during service

Answer

Designing a base large enough to prevent tipping on the build plate

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

Chamfers look aesthetically better than fillets

Answer

Chamfers are easier to model in CAD software

Answer

Chamfers increase impact strength more than fillets

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

Non-manifold meshes produce larger file sizes that overload the printer

Answer

Non-manifold geometry reduces part color accuracy

Answer

Gaps in the mesh increase print time unnecessarily

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

0.001–0.005mm (slip fit, same as machined metal)

Answer

1.0–2.0mm to guarantee easy assembly

Answer

No clearance — design at nominal size and sand to fit

Question 6

What is the main engineering advantage of designing 'print-in-place' mechanisms for 3D printed assemblies?

Accepted Answer

Moving assemblies such as hinges and joints are printed fully functional in a single job, eliminating assembly steps

Answer

Print-in-place parts use less filament than equivalent solid parts

Answer

Print-in-place designs always achieve tighter tolerances than assembled parts

Answer

Print-in-place parts cure faster under UV light

Question 7

What is the fundamental shift in design philosophy between traditional 'Design for Manufacturability' (DFM) and 'Design for Additive Manufacturing' (DfAM)?

Accepted Answer

Traditional DFM minimizes geometric complexity to ease machining, while DfAM embraces complexity wherever it adds function or reduces part count

Answer

Traditional DFM encourages complex geometry while DfAM demands simplicity

Answer

DfAM always produces stronger parts than traditional DFM methods

Answer

Traditional DFM is always faster and cheaper than DfAM for any volume