Air raid siren

One of my first designs after finally getting a 3d printer. Came out functional, needing quite high rpms to work. Im assuming because of the size of the airways. Would probably work better at a larger scale (will update).

note: I locked the siren to the rod with a small screw through the side. you could also glue or find another option, but it does need to be locked to the rod somehow.The purple disks shown are unneeded connectors that aren necessary.

print 4 washers,1 for each side of the 2 bearings.

Not 3d printed:

The axle is 8mm threaded rod
2 nuts for rod
2 skateboard bearings, 8mm id, 12mm od(probably not needed but the housing is spaced for them so you'd need to print discs for a replacement if need be)
1 tiny screw