Squeeze Breeze — Trigger-Spun Fan Toy (no batteries, mechanical novelty)

Squeeze Breeze — Trigger-Spun Fan Toy

A no-batteries mechanical novelty toy : squeeze the finger trigger and a multi-blade propeller on a flywheel spins up through a one-way ratchet, then coasts between squeezes. A genuinely satisfying hand-powered fidget that looks like a little hand fan.

⚠ PLEASE READ — this is a TOY, not a real fan

It does NOT produce a real cooling breeze. The mechanism is fun — the blades really do spin up and keep going — but the airflow you feel is, at best, a faint wisp. Buy it as a mechanical fidget / desk toy / conversation piece , not as a way to cool down at the beach. I'd rather set the right expectation than have you disappointed. (Also note: the optional front grille/cover is left off this release — it fouled the rotor and wouldn't stay seated, so the fan ships open-faced . An open-face cover is on the to-fix list.)

How it works

- The trigger carries a sector gear that drives a pinion at 4 : 1 .

- The pinion turns an external ratchet ring ; the rotor's pawls catch it on the squeeze and drive the prop, then click freely past on the spring return (an overrunning clutch) — so every squeeze adds spin in one direction.

- A perimeter flywheel stores the momentum so the prop coasts between pumps.

- A built-in leaf spring resets the trigger.

Parts (5 printed parts, open-faced)

STL

Qty

Role

tbf_body.stl

1

Pistol grip + fan-head cage + two posts

tbf_trigger.stl

1

Finger lever + 48-tooth sector gear + return leaf spring

tbf_driver.stl

1

12-tooth pinion fused to the ratchet ring (overrunning clutch)

tbf_rotor_print.stl

1

Two pawls + 7 pitched blades + flywheel rim (pre-flipped for the bed)

tbf_caps.stl

1

Prints two press-in retainer caps (one per post)

Assembly (no glue, no screws — ~2 minutes)

Step 1 — Trigger onto Post A. Line the sector gear up with the vertical slot in the grip-side cage wall and lower the trigger straight down until it sits flat in the grip. Flick the leaf-spring tip past the body's little reaction post so it pre-loads — the lever should now swing and spring back on its own .

Step 2 — Driver onto Post B (central fan post), pinion-down. It must mesh with the trigger's sector gear — rock the trigger and the driver should turn.

Step 3 — Rotor onto Post B , on top of the driver. Its two pawls land around the ratchet ring. Check the clutch: turn one way it catches , the other way it clicks freely .

Step 4 — Press a cap into each post (stem-down). The caps trap the spinning parts so they can't lift off but still spin. That's it — squeeze and it spins.

Print notes

- 0.2 mm layers, no supports , every part prints flat.

- PETG recommended for the trigger (the leaf spring is cycled); PLA fine for the rest.

- Assembled ≈ 87 × 179 × 42 mm.

Designed from scratch in parametric OpenSCAD (no AI-generated geometry) — tweak the gear ratio, blade pitch, flywheel mass, and spring to taste. The .scad source is attached.