This is an air defense siren driven by a brushless motor

The only component that needs to be added with a support structure is the "Sirene Rotor1".

I used the Replicator 2 3D printer to print. Among them, the sizes of the two models, "Sirene Wand" and "Sirene Deckel", are too large. If you want to print them on the Replicator 2, you need to adjust the layout slightly - move these parts closer to the printing platform along the Y axis to ensure the printing accuracy.

Here is the actual sound effect of the alarm...
https://www.youtube.com/watch?v=xOa8Jh2RAUA&feature=youtu.be

You also need to prepare the following accessories:

• Motor: RC Timer 5010-360KV
• Remote control-related accessories: a 20A ESC and a connecting cable used to transmit control signals to the ESC
• 4 M3×20mm screws
• A bearing: inner diameter 5mm, outer diameter 11mm, width 4mm —— which is completely consistent with the bearing specifications used by RCTimer motors.

I've long had the idea of using Arduino or Raspberry Pi to implement various alarm functions, and it's actually not that difficult to do. It's just that I've never dealt with this kind of hardware device before... However, if I can successfully develop such a system and use it as an alarm clock when I wake up in the morning, it would definitely be both practical and efficient!