Some people look at a 3D printer and think "this will make useful parts for my projects." Some people hear an air raid siren, and assume there must be an historical war re-enactment taking place nearby.
I am the third type of person, who hears a 3D-printed air raid siren and experiences a flash forward to my apocalyptic future yet to come. Bear with me here folks, I'm cooking.
Youtuber Mark Makies has created a 3D printer air raid siren. This you probably know, if you viewed the video above (via Hackaday). What I'm not entirely sure of is why it sounds like both a comedy bit in once-popular children's TV show Noddy's Toyland Adventures, and the sound of impending doom, all at once.
It's a cool project, anyway, and I'm all down for that. A combination of cheerfully-coloured 3D-printed components and RC parts have been employed to make something both charming and terrifying, and for this Mark should be applauded.
Internally, a brushless motor controlled by a speed controller turns a rotor, which pulses air pressure inside a stator. The slots inside the stator (stay with me, this is technical) make a wooooooo sound through the honking trumpet, and cause the hairs to stand up on the back of my neck. Something like that, anyway.
Impressive. A potentiometer attached to the speed controller means the pitch can be adjusted by ramping the speed of the motor up and down, meaning those wooooos can become weeeees, and so forth. And for some reason, it reminds me of my youth.
I grew up in a small town just outside London, and every Tuesday morning a WW2 air raid siren would go off, waking me from my slumber/hangover. To this very day, I know not why. Friends would discuss it over an afternoon pint. Why does the siren sing for thee?
Still, it was both a useful way to tell me I was late for work, and a good excuse to check the skies to make sure the end times had not begun while I slept, blissfully unaware of my potential fate. The world kept turning, and the siren, it seemed to sing for no reason at all.
This video takes me back to those times. Ah, the halcyon days. Now, I fear that one day, I will hear the siren again. Hopefully it's a brightly coloured one, at least.
