Not really complete yet, not really worth uploading yet and probably of no use to anyone…
I am in the process of creating another siren…
Don’t really know why but I like sirens.
I turn small and bigger motors with suitable mounting options into a siren, let them blast for bit and call it day.
I got one of these little double wheel bench grinders gifted to me…
Crappy Chinese plastic, weak motor, the switch falling apart and the disks abused to the max…
What better ■■■■ to turn into a dual wheel siren…
With a max siren housing diameter of 18cm when sitting on a flat surface it was also of perfect size for my P1S 
I will keep this topic update if anyone else has an interest in turning a bench grinder into a siren…
For this siren, due to the speed of grinder and size of the rotor I had to get a bit creative…
My first attempt was basically just a sized up version of a siren I created a few years ago.
Quite simple, quite loud and easy to print…
Lasted about 10 second until it turned into flying shrapnel…
Seems the laws of physics still apply to printed siren rotors rotating too fast…
Next one had stronger fins and all, lasted longer but suffered a catastrophic failure once the cover was on.
Wasn’t thick and sturdy enough, got bowed in a little bit and made contact with the rotating bits…
One thing I did not realise during the short time the rotors lasted so far was that the collar on the shaft is worn out by those those abused grinding disks.
Resulting on the rotor not getting a proper grip and requiring tight tolerances on a very worn out and uneven shaft LOL
I am now testing a centrifugal fan approach where the rotor is printed in one piece with all fins and COVER.
Eliminating the need to add a cover on the housing with impossibly small gaps to prevent air leaking out.
Let’s see how it turns out…