Eyewear Industry Event Guide: 5 Basics for 3D Printed Frames

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  Key takeaways
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  What makes eyewear hard to print
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  Matching the process to the frame style
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  Materials that hold up on a face
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  Surface finishing and the numbers behind it
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  Process vs. frame requirement

A frame front is a thin shell with compound curvature. The rim thickness often runs 1.5–2.5 mm, and the curve changes direction across the lens area. FDM handles this shape, but the layer lines run across the most visible surface. Resin processes hide the lines better and hold a 0.05 mm layer, so the front reads as smooth after light sanding.

The temples are a different problem. They are long, slender, and loaded in bending. Print them flat on the build plate and the layers run perpendicular to the load, which is the weak direction. Print them standing and you add support scars along the hinge side. Neither choice is free. Most teams orient temples at a shallow angle and accept a small amount of post-processing.

Hinge bores and lens grooves are the parts that decide whether the frame works. A printed bore comes out 0.1–0.3 mm undersized depending on the process and shrinks unevenly. If the bore is round within 0.05 mm, a light ream brings it to size. If it is oval, the temple will wobble no matter how tight the screw is.

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  Rim wall1.5–2.5 mm is printable; below 1.2 mm, scrap rates climb fast.
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  Temple sectionKeep the thinnest cross-section above 2 mm for resin, 3 mm for FDM.
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  Hinge borePrint undersize by 0.1–0.3 mm, then ream to the pin diameter.

Not every frame should be printed. A classic acetate shape with flat surfaces and a simple hinge is faster to cut from sheet or mold. Printing pays off when the geometry is organic, when the run is small, or when each unit needs a different fit. Those three conditions show up often in custom and sports eyewear.

For a pilot run of 20 to 200 frames, resin printing gives the best surface per dollar. Layer height 0.05 mm, walls at 2 mm, and a light bead blast produce a frame that can be worn and tested. If the frame needs to survive impact testing, move the temples to CNC-machined aluminum or titanium and keep the front printed.

Full production is a separate decision. At 10,000 units and above, injection molding usually wins on unit cost, but the tooling lead time and the cost of a design change are real. A hybrid route works well: print the front for the first market test, then cut the mold once the fit is confirmed.

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  1–20 framesPrint everything. Resin for surface, FDM for quick fit checks.
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  20–200 framesPrinted front, machined metal temples for durability.
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  200–10,000 framesVacuum casting or urethane tooling bridges the gap.
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  10,000+ framesInjection molding, but only after the design is frozen.

Skin contact changes the material shortlist. The frame sits against the nose and behind the ears for hours, so the material has to resist sweat, sunscreen, and repeated cleaning. PLA is easy to print and cheap, but it softens near 60 °C, which is a normal car interior in summer. A frame left on a dashboard can deform.

Nylon PA12 and PA11 are the common choices for printed frames. They take impact, they flex without cracking, and they tolerate the solvents in everyday cleaners. Resin parts look better out of the machine, but standard resins get brittle with UV exposure. If the frame will be worn outdoors, specify a resin rated for UV or plan a coating.

For metal frames, titanium and aluminum are both workable. Ti-6Al-4V is strong and light but expensive to machine and slow to print. Aluminum 6061 machines fast, anodizes cleanly, and suits temples, hinges, and bridge plates. Stainless 316L works for pins and small hardware where wear matters more than weight.

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  PA12 / PA11Tough, flexible, good for full frames and temples.
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  UV-stable resinBest surface finish; needs coating for outdoor use.
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  Aluminum 6061-T6Machined temples, bridge plates, anodized colors.
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  Ti-6Al-4VLight and strong; higher cost and longer lead time.

A printed frame comes off the machine with visible layer steps. On an FDM part, the step height equals the layer height, so a 0.2 mm layer leaves a 0.2 mm ridge. That is roughly Ra 8–12 μm, which feels rough against the skin. Tumbling in ceramic media for 30–60 minutes knocks the peaks down and gets the surface to Ra 3.2–6.3 μm.

Bead blasting after tumbling gives a uniform matte look and hides the remaining tool marks. For a smoother finish, polishing brings the surface to Ra 0.8–1.6 μm, which is the range most people expect from a premium frame. That range is also what we hold on machined aluminum temples.

Color is the last step. Anodizing works on aluminum and titanium but not on nylon. Printed nylon takes dye well, though the color penetrates only 0.1–0.2 mm. Laser marking handles logos and size text; the minimum character height we recommend is 1.5 mm, below which the marks blur.

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  As printedRa 8–12 μm, layer steps visible.
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  TumbledRa 3.2–6.3 μm, steps softened, matte look.
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  PolishedRa 0.8–1.6 μm, smooth and uniform.