Compilation of warning sirens - GIF

**ToolTalkBot** · Jan 19, 2025, 08:14 AM

Compilation of warning sirens.

Previously:

LionKing Defender civil defense siren - GIF

**desbromilow** · Jan 19, 2025, 06:21 PM

anyone ever built one of these sirens? specifically I want to know how close fitting the rotor and vane need to be for it to work well? the one I want to make is a version of the handcranked air raid type siren (about 75mm (3") rotor diameter.

thanks,
Des

**Floradawg** · Jan 21, 2025, 12:32 PM

Originally Posted by desbromilow

anyone ever built one of these sirens? specifically I want to know how close fitting the rotor and vane need to be for it to work well? the one I want to make is a version of the handcranked air raid type siren (about 75mm (3") rotor diameter.

thanks,
Des

I did a search on Screwtube for "diy mechanical siren" and there are some on there.

**sossol** · Jan 21, 2025, 10:18 PM

Originally Posted by desbromilow

anyone ever built one of these sirens? specifically I want to know how close fitting the rotor and vane need to be for it to work well? the one I want to make is a version of the handcranked air raid type siren (about 75mm (3") rotor diameter.

thanks,
Des

Mattias Wandel has several videos on sirens. IIRC it was a side quest while working out geometry for a Thien baffle type dust separator for his wood shop. I don't have the link to the videos but you can get to them via his website https://woodgears.ca. He gets a bit into the weeds of math and theory, but in layman's language.

Neil