air raid siren makita angle grinder

thingiverse

I'm developing 3D printed attachments that can be attached to an angle grinder, producing the sound of an air raid siren. The Makita DGA504 battery-operated tool has the ideal RPM of 8500; however, when used with a standard grinder, the RPM is too high, resulting in poor sound quality. To resolve this issue, I employed a voltage regulator to lower the voltage. As seen on the video, the sound improves significantly when the RPM is brought within optimal range. You can find more innovative designs by checking out my other creations.