Christmas Napkin Rings - Diamond or Tree Windows, Custom Initial, No Supports

Dress the Christmas table in an evening. These twelve-sided napkin rings carry a row of Scandinavian diamond windows or little Christmas tree windows all the way round. Put a guest's initial on the front facet and the ring is a place card too: everyone finds their seat, and the ring goes home as a small keepsake. This one is free, a small Christmas gift from us to the community.

Why they print so clean. The windows were drawn for printing upright: the diamonds stand on their points at 45° and the trees point up, so not a single window has a flat roof that needs support or sags. The top and bottom edges are chamfered at 45°, which also keeps the first layer clear of elephant foot.

SIZE: 50.4 mm across the corners (48.7 mm across the flats), 32 mm tall. The hole is 43.9 mm round, for a rolled or folded cloth napkin up to about 40 mm thick. The wall is 2.4 mm at the middle of each facet and 3.2 mm at the corners.

Patterns

• Diamonds: on every facet a 9.9 mm diamond window with a small diamond above and below it.

• Trees: on every facet a tree window 8.8 mm wide and 11 mm tall.

• With an initial: the front facet has no window and carries a 13 mm letter engraved 0.8 mm deep; the other eleven facets keep the pattern.

IN THE FILES

• diamonds-red: diamond pattern all round

• trees-green: tree pattern all round

• diamonds-initial_A-gold: diamond pattern with an example initial "A"

• napkin_ring_set.scad: the parametric source. Type any letter into initial (for example "K"), pick diamonds or trees, and export your own ring.

• 3MF plates: 6 diamond rings, 6 tree rings, and the initial ring.

The colour in the file name is only a suggestion. Each ring is one colour, so no AMS is needed; red, pine green, white and silk gold look great together on a table.

PRINT SETTINGS: PLA (silk gold, red, green or white), 0.20 mm layers, 3 walls, 20 % infill, no supports. Rings stand upright on their end. Six rings take 220 × 107 mm of the bed, and nine fit on a small 180 mm bed.

Honest notes:

• The images are 3D renders made from the same files you print. These rings have not been test-printed yet.

• Checked numerically on the exported STLs: each file is one closed solid, 50.4 × 50.4 × 32 mm; no window has an overhang, nothing starts in mid-air.

• The very tips of the windows narrow to under 0.3 mm in the last one or two layers and close up, so the windows come out 0.2-0.4 mm shorter than drawn. That is cosmetic.

• The crossbar of the engraved letter has a 0.8 mm flat ceiling; it bridges easily, but a very soft first layer can blur small letters. Bold capital letters read best.

• The design is original: no licensed characters, no brands.