Engineering a design for 3D printing
Source article here
Local copy of article, because it's that good
- Designing for Part Strength
- R1.1 — Tensile forces should be aligned parallel to the print surface.
- R1.2 — Split a part into multiple pieces when no orientation is ideal for all loads.
- R1.3 — Most strength comes from the part's surface, not the infill.
- R1.4 — Guide forces on the most direct path possible.
- R1.5 — Use large cross sections. Prefer thick shapes over thin shapes.
- Manufacturing Tolerance and Part Finish
- R2.1 — Use chamfers on edges parallel to the print surface. Use fillets on edges vertical to the print surface.
- R2.2 — Improve horizontal holes by using a teardrop shape or giving the hole a flat roof.
- R2.3 — Use a teardrop shape for vertical holes to avoid inaccuracy due to perimeter seams.
- R2.4 — Consider where the seam will be placed. If tolerances are tight, provide a sharp concave corner for the seam the hide in.
- R2.5 — Design part geometry for easy motion paths while printing, to improve dimensional accuracy.
- R2.6 — Prevent warping by making parts voluminous and their surfaces smooth and rounded. The ideal shape is a sphere.
- R2.7 — If you can't make it precise, make it adjustable.
- R2.8 — Do not use circular holes for interference fits. Use hexagon or square holes instead.
- R2.9 — Use crush ribs for press fits that are only assembled once.
- R2.10 — Use grip fins for press fits that need to be reassembled more than once.
- Process Optimization
- R3.1 — Avoid the necessity of support material.
- R3.2 — Clever part orientation on the print surface can eliminate the need for supports.
- R3.3 — Split a part into multiple pieces when no orientation can avoid supports.
- R3.4 — Use sacrificial layers to avoid internal overhangs that would otherwise require supports.
- R3.5 — Use the overhanging counterbore trick.
- R3.6 — Bridges on top of other bridges allow for advanced geometry, without requiring additional support structure.
- R3.7 — Keep surface area minimal. Design voluminous. Do not make cutouts in an attempt to save material.
- R3.8 — Reduce the surface area that is touching the print-bed when aiming for mass production.
- R3.9 — Add mouse ears to parts that have problems with bed adhesion.
- Functional Integration
- R4.1 — Use zip tie channels to fasten cables to a part.
- R4.2 — Use flexures to integrate moving features into a part.
- R4.3 — Design flexures such that they only deform elastically when used.
- R4.4 — Ensure that flexures have hard limits that prevent breaking them.
- R4.5 — Ensure clips won't break from use. Optimize designs for minimal clip movement.
- R4.6 — Provide a way to undo form-locking clips.
- R4.7 — Use break-away surfaces to support floating geometry in print-in-place designs.
- R4.8 — Ensure sufficient clearance between features in print-in-place designs.
- Beyond plastic - Machine Elements
- R5.1 — Protect dynamically loaded screws with additional locking measures like threadlocking adhesive.
- R5.2 — Design screwed connections for maximum screw length.
- R5.3 — Cut threads into printed parts with a thread tap for quick design of low-reuse joints.
- R5.4 — Use rib thread forming for no-postprocessing low-reuse threads in printed parts.
- R5.5 — Use heat-set threaded inserts to add highly reusable and robust threads to a part.
- R5.6 — Make cutouts to embed standard nuts into a part.
- R5.7 — Embed hardware into 3d-printed parts to avoid more complex fastening or joining methods.
- Appearance
- R6.1 — Complex shapes are often "for free" in 3d-printing. Use them to improve appearance or ergonomics.
- R6.2 — Create shadow lines along the joining edge between two parts.
- R6.3 — Use surface texture to make parts appear less 3d-printed.
- R6.4 — Prefer engraving text over embossing.
- R6.5 — Place engraved/embossed text vertical to the print surface.
- Extra: Vase Mode Design
- R7.1 — Use beading patterns to make vase mode parts more stiff.