Home Siren Idea2 kinda crazy.

[loudmouth]

while i was reading one of the small engine books i own *trying to figure out some thing very simple* any ways i was looking at the flywheel when i got an crazy idea. If I take a fly wheel
http://jnem2.home.att.net/pics/30811AFlywheel.jpg
and had a friend who welds like a Pro take some square peaces of metal or aluminum if the wheel is, have them welded on every other port on the flywheel and grinded flush to the side. Then form some type of band that wraps around the wheel and is enough to cover up the ports on the rotor and cut holes into the band so it will act like a stator. Now it gets even more tricky should it be mounted to the old engine or on to a high torque stationary buffing wheel. Now in theory it should work if it stays balanced and if the vains on the flywheel catch the air and pull it towards the ports.
but that just in my head and I may just try it since I have allot of extra parts in the shied.
and feel free to tell me it wount work just gives me more to work on in my head. and if your self feel like trying this go right ahead!

[StonedChipmunk]

That would be one HELL of a high pitched siren!!!! (If you count one opening per port.) 18 port siren? Wow... if that thing ran at 3,450 RPM (which is about the speed for an average siren) then this is what it would sound like:
http://media.putfile.com/18-Port-Siren-at-3450-RPM
(warning... this is very high-pitched and annoying... turn down your volume!)

Note: Mathematically, that is what it would sound like... but since this is a simple tone generation using average siren specifics, it probably won't be anywhere near that.

Actually, it depends on how many RPMs the motor will do, plus how many ports you actually plan to have (18 is a bit much unless you are going to have a really slow RPM).

[loudmouth]

OooOoh my ears, i think i can find a lower the Rpm and probly double cover some of the ports to nock the pitch down or just have fun and play with port ratios.
thanks Stonechimpmunk for the sound.

[SirenMadness]

Though this idea would work, the amount of sound naturally expelled out of the rotor would not be that high, with a very high pitch. You could have a concentrated stream of compressed air make the siren louder, though allot of air would be needed to get its pressure in a piece of metal of that size to be efficient.

BTW, Loudmouth, are you planning to cover the ports of the rotor or of the stator? Covering the stator ports won't change the pitch.

[loudmouth]

Rotor ports. I think im going to take a 2 stroke flywheel first since its small and easy to work with. like this one
http://static.howstuffworks.com/gif/chainsaw11.jpg
it be a 5 port and this one might be realy neat sounding. plus i could spin this with alot less force.

[Blasty]

The first thing that came to my mind when I saw a flywheel like that on a lawnmower was "Hey, that might make a good siren!" However, lacking the proper tools, I never ventured past that stage.

It will be interesting to see what you come up with if you can get that rotor welded and keep it balanced. Good luck!

[SoundOff]

You just reminded me of the bathroom vent fans in my house. I was changing a bulb in my bathroom since the fan also has the light and I noticed the actual fan was similar to a siren rotor. If one can get a replacment motor/impeller assembly, it can probably be modified with pieces of plastic glued on and a stator created.

[loudmouth]

Our old bathroom fan was that same exact way and i never even thougt about it even tho its hanging right above my head. All tho that fan is now long gone and we have the "updated" virsion with the 100 or so fan blades now that would one strange siren 50 port ..

[StonedChipmunk]

I had a vacuum motor like that, should have kept it >.<

Anyways, I have no idea how many RPMs this thing will do, but assuming it will be 5 ports, it will sound like this:

@ 1800 RPM: http://media.putfile.com/5-Port-Siren-at-1800-RPM
@ 3000 RPM: http://media.putfile.com/5-Port-Siren-at-3000-RPM
@ 5000 RPM: http://media.putfile.com/5-Port-Siren-at-5000-RPM

Clearly, the tone really depends on the RPM you plan to run this thing at.

loudmouth: If my calculations are correct, this is what it would sound like: http://media.putfile.com/50-Port-Siren-at-2000-RPM
***WARNING!*** This is EXTREMELY HIGH-PITCHED and may cause hearing problems at high or even normal volume! TURN DOWN YOUR VOLUME!
2000 RPM was as high as I could go while still preventing a headache. But, if you want to hear that siren at 5000 RPM (DANGER!) then click here.

[SirenMadness]

Wow, I must be really talented at enduring high-pitch sounds.

I've found an inoperative mower near the railroad that I live a block away from, and I wanted to take the cooling fan off to make a siren-rotor out of it, though getting it off was a very hard task. If you have a lathe and an air-compressor at home, you could create a siren, similarly to the one that I've assembled for the dawn of '07; yes, I still need to buy a DVD-burner to finally show the video!