Safety Whistle

An incredibly compact, loud (100db+) safety whistle to alert others nearby of present or active danger.

Print Details

• Material: 1.26g / 0.43m

• Time: 3m

• Size: 36mm x 11mm x 4mm

Print Settings and Tips

My settings and setup are as follows:

• Nozzle Size: 0.4mm

• Layer Height: 0.28mm

• Perimeters: 2

• Infill: 0%

• Supports: No

Consider rotating your bridges so they go the short way across the whistle.

Source and Other Platforms

Available on OnShape
Available on MakerWorld
Available on Thingiverse

Acknowledgements

While I iterated on the internal chambers and overall size, I did so only after studying the Flat Pocket Whistle by Jonas Daehnert and the Micro Bitonal Whistle by AC Studio.

If you like my work, consider supporting folks doing great work to protect our neighbors.

Updates

[ 1/29/2026 ] Height modifications and tests.

After printing several hundred of these, I decided to reduce the height by 1mm to save a little (0.08g) filament per print. The volume of the whistle is maintained, and it is not too much harder to blow into. I had originally tried a 3mm height, and while it was successful, it required a lot more effort to blow into than I liked. 

I also enjoyed the robustness of the thicker loop, so that is the default approach now.