One-Way Ratchet Hand Fan with Spring Return

This is my experimental fully 3D printable hand-powered fan with a ratchet + one-way clutch mechanism.

The main goal of this project was not only to create a working fan, but also to learn how to design a free-return lever system with one-way rotation using only 3D printed parts.

The fan rotates only in one direction using a ratchet system with 3 independent pawls.
During the return movement, the pawls freely fold inward, allowing smooth reverse lever motion without rotating the propeller backward.

The handle automatically returns thanks to a simple spring taken from a regular ballpoint pen.

⚠️ File Update: New 3MF and STL files added — “Textured Grip”

The handle consists of two separate parts and slides onto the fan body for easy installation.

Upgraded with a custom Textured Comfort Grip for improved handling and comfort.
Printed in PLA using a textured outer wall finish, creating a rough tactile surface that feels great in the hand while adding extra grip and a premium appearance.

Almost the entire model is fully printable:

printed gears
printed axles
printed mechanism
printed body

The only non-printed part is:

1x ballpoint pen spring

The fan actually works surprisingly well and can even blow out a candle flame 😄
But I still consider this more of a mechanical learning project and a platform for improvements and community ideas.

Printing

Material used: PETG Basic

Build plate: Bambu Cool Plate SuperTack

Assembly Guide: 
Step 1
After printing, check that all gears rotate freely on their shafts.

Because of material shrinkage, humidity, printer calibration, and other factors, some holes may become tight.

For this mechanism, free movement is extremely important.

My parts worked perfectly from the first print, but if your gears rotate too tightly: use a round file, carefully enlarge the holes. Do not force the gears.

Step 2 (Most Important)

Make sure the 3 pawls inside the main ratchet gear move freely.

They must:
fold inward during reverse lever movement
expand outward during forward push

You can test this without the spring:
place the large gear into one side of the body
install the handle
manually move the handle in both directions

The mechanism should:
engage in one direction
freewheel in the other direction

This step is critical.

Step 3

Install the second (middle-sized) gear and check free rotation again.

Step 4
Install the third gear and test the movement once more.

Step 5
Install the propeller gear.

If: all gears rotate freely, the 3 pawls move correctly

then: install the second body half, install the second handle half

After that:
insert the pen spring, test the mechanism without the propeller first.
The handle should move smoothly in both directions.

Final Assembly
If the body does not close tightly enough, you can use a tiny drop of glue around the perimeter.

Install the propeller last.

There is also a small hole at the bottom corner of the body:
for a string
for carrying
or for future accessories

Community Ideas Wanted 👀

Since this fan was mainly designed to explore the free-return ratchet system, I would love to see your improvements.

Ideas I would love to see:
ergonomic hand grip attachment
clip-on handle extensions
improved propeller blades
high-efficiency fan designs
stronger airflow versions
folding handles
decorative body styles

The bottom hole in the body can be used as a mounting point for accessories.

If you redesign the propeller and achieve better airflow — please share it 😄
I am still learning propeller design myself.

Thanks for printing the model, and I would love to hear your feedback and see your remixes.