Wooden Bow Tie

Two wooden-look bow tie designs in one project, made for my 3-year-old and printed and tested on a Bambu Lab X2D (0.4 mm nozzle) on a textured PEI plate. They also work for grown-ups – the OpenSCAD source lets you change the size. Plate 1 – Wooden Bow Tie (wood PLA, about 35 min, 5.7 g) 75 x 35 mm bow tie with engraved, irregular wood-grain lines. It prints face-down, so the front gets the plate's texture and has no layer lines. A built-in bridge on the back (7.8 x 2.8 mm tunnel, rounded and flared entrances) takes a 6 mm soft elastic loop. Plate 2 – Clip-on centre knot (PETG, about 12 min, 0.6 g) Presses onto the centre from the front and clicks behind the back edge. The wings pass through its open ends and the elastic tunnel stays clear. Glue it on permanently (see Assembly). Plate 3 – Classic Bow Tie (wood PLA, about 39 min) Simpler bow tie with a raised centre knot and four cord holes for an elastic or cord. Printed flat on its back, with 0.08 mm layers on the knot for a smooth finish. Print settings (already in the print profile)

- Wood PLA: 205 °C (210 °C first layer), bed 55 °C, 0.12 mm layers, 3 walls, 15 % gyroid, no supports, no brim.

- PETG knot: 245 °C (250 °C first layer), bed 70 °C, fan 30–50 %, 12 s minimum layer time, 0.8 mm retraction.

- Any wood PLA or regular PLA works for the bow ties; PETG or PLA works for the knot. A textured plate gives the nicest front.

Assembly

- Click the knot onto the centre, then fix it permanently with a few small dots of gel super glue or epoxy. Let it cure for 24 h.

- Thread about 100 mm of 6 mm soft flat elastic through the tunnel on the back and sew the ends into a loop that hooks over the shirt's top button (nothing goes around the neck).

- Lightly sand any sharp edges.

Safety For children: an adult should put it on, supervise while it is worn, and take it off for naps and sleep. The knot is a small part, so make sure it is glued. Before first use, hang about 2 kg from the elastic loop for a minute and check for cracks. Not a toy. Files Bambu Studio 3mf with all three plates and settings, STLs, and the parametric OpenSCAD source (size, thickness, grain, knot and elastic bridge are all adjustable).