What it is?????

A compact ventilator that uses a falling weight to spin a propeller through a multi-stage gear train. As the weight descends, it pulls a cord wrapped around the first gear. That rotation is multiplied by the gears so the final small gear and propeller spin much faster, producing airflow.

Its fun diy! It will spin to 5-15 min depend how long a wire is !!

Gear ratio explained (why the last gear spins faster)

• Gear ratio (one stage) = (teeth on driven gear) / (teeth on driver gear).
• Output speed = Input speed / Gear ratio.
• If a large driver turns a small driven gear (e.g., 60T → 20T):
• Ratio = 20/60 = 0.33 → output ≈ 3× faster.
• If a small driver turns a large driven gear (e.g., 15T → 50T):
• Ratio = 50/15 ≈ 3.33 → output ≈ 3.33× slower (but with more torque).
• In your ventilator, several speed-up stages are cascaded. Multiply stage ratios to get the total speed-up.
• Example: (60→20) × (45→15) × (40→10) ≈ 3 × 3 × 4 = 36× faster at the prop.

So yes—if you spin the first gear, the last gear will spin much faster thanks to those step-up ratios.

• TIPS-make sure each gear spins correctly clear it from unwanted filament iff needed lubricate the gears for for better spinning,
• Apply a thin film of PTFE or silicone grease to the gear teeth and bushings/bearings.
• Wipe off excess; too much grease attracts dust and adds drag.

Break-in

• Spin the train by hand for 3–5 minutes to polish contact points before first run.
• make a space for each gear at least 2-3 mm so it wont touch to each other
• Rewind the cord and raise the weight to store more potential energy. 2-4kg

ASSEMBLING!!!!

Before glue make sure everything spins correct!

I added my table folder but you need figure out how to secure to your table.