121.6 dB Dremel Siren V2.5 (4-5 Port)

This is designed for the Dremel 7760 (Dremel Lite). On V.2 of this siren, however, it have worked with different models, so a different model of Dremel might be compatible, but I can't guarantee compatibility. The dB measurement was performed on max speed on a Dremel 7760 (Dremel Lite). If your Dremel is less powerful than mine, it may be quieter. Also check to make sure before you print when you look at your Dremel from the top that is spins counter-clockwise. If it doesn't, the siren will be quieter than intended.

I was kind of amazed by the popularity of my V.2 Dremel siren, and decided I should combine the dual tone aspect of the V.1 siren with the loudness of the V.2 siren. This was pretty hard to model given all of the revolved features and the need to precisely implement the vanes on the chopper. I chose 4/5 port as I wanted it to sound a bit like a Thunderbolt 1000T. This siren has some problems with gyroscopic forces when you move it rapidly while on, and it will scrape the stator.

The blade design features backward curved vanes as well as a curve on the Z axis to optimize static pressure for maximum loudness. I tweaked the blade geometry a bit from the last design, and added fillets to the bottom and top stage of the chopper, which seemed to have made it even louder while being almost the same form factor. The tolerances of the chuck are a tiny bit tighter due to me getting a A1 Mini, which has much better dimensional accuracy than my Ender 3 Pro.

A horn STL for this siren does exist, but I didn't put it in the print profile as it is so large and after all, who wants to waste more filament on making yourself deaf :/

ASSEMBLY: (yes weird compression artifacts on GIF)