 Okay, after my first siren project, I did a little more research and decided to build another miniature siren. And this time, I'm actually thinking I'm going to attempt to build the world's smallest air raid siren, even smaller than those little siren flashlights. Okay, I've got two pieces of PVC pipe here. They fit nicely inside each other. Actually, it's a pretty tight fit. I'm going to need to sand down the outside of this one and the inside of this one to get it to be able to spin nicely. But should work pretty well. This one will act as the chopper and this one the stator. And I'm going to run the whole thing with this tiny little nine volt. This thing is miniature. And I'm not actually going to run it off nine volts because at nine volts, this thing will get up to 24,000 RPM, which is a little fast for a siren. Yeah, I figure if I run it off a double layer too, it should give us a nice siren worthy RPM and should be an interesting project. All right, well, let's get started. Okay, get the inside chopper all sanded down. Cameras not really focusing too well, so you can't really see. But now fits in. I also sanded the inside of the stator. Fits in real nice. Yeah, really good. Spin's pretty nice. Didn't know very close to ounces should push enough air and time to think I'm going to go with like a five or six port design. Time to mark off where the hole should be and I'm going to just keep the rotor in there and drill through both the stator and the chopper at once and then the hole should line up just fine. All right, I got the stator and the rotor or chopper. Oops, drilled all nice. They fit real nicely on each other. And see if I can line up the whole, holes line up real nice. Still spins pretty well. I might sand it down a little bit more. But yeah, I'm a little curious to see how the round holes work because almost every single air raid siren uses square rectangular holes because it produces a more distinct shockwave apparently. I learned that on Yahoo Answers when I asked if round holes would work, but it's just easier to drill small things out than I don't have a dremel or anything. We'll see if this works. It should be pretty cool. And I think I might fit some small aluminum blades in there just sticking out from the edges out of this sheet metal aluminum just to make sure it draws air in, but I might do that after I've already tested it. All right, so let's get this mounted on the motor. Okay, here's the chopper mounted on the motor. I decided not to use that tiny little nine volt because it just wasn't working out for me. It wasn't being very nice and mounting. It's just easier to use a little bit bigger motor. This is a 9 to 18 volt motor. I already got a switch on it. And it's the stator. I'm going to put some blades in the impeller, just little aluminum things or plastic things or maybe hot glue them just to get some air moving through. All right. Got the blades in there. Rotor blades. They're hot glue ins, so it's not the cleanest job, but it's not bad. They're all about the same level and I'll probably move some air. Got a temporary mount here on the side of this old printer. Just to test to see if everything works out all right. And let's see how she spins. Okay. After that test, I noticed not much, but a little bit of wobble when it was spinning. So I re-glued it, mounted it on this gear. And now it spins great. I'll show you in just a little bit when the super glue is completely dry. And maybe we'll test it. See if we can get a sound. Okay. Now I'm just going to give you a little sample of the little bit of sound it makes at this stage. Again, it's not a very loud siren, but it is a siren. Nonetheless, I found out. So let's see how it works out. It still bumps the side a little bit, but it makes a noise. Pretty cool if I don't say so myself. And once I get this finalized, I'll make another video. And then we'll hear really rev up. All right. Here's a video proving that this thing does move quite a bit of air for its size. Just a little piece of tissue paper. Not bad. Just approved that wasn't fake. Okay. Here's another test. I grinded down the chopper a little bit and the inside of the stator and the taunts are very close. The clearance is and it's hard to hold it on, but I can get it so it doesn't grab drag on the sides. So let's see if I can do it for you. Oops. It's hard to do. Okay. After a lot of mounting trouble, I present to you what is perhaps the world's smallest air raid siren. The entire motor and everything is concealed within this half of a can, which is mounted to this little aluminum plate, which tends to vibrate a lot, so that's why it's on the shirt. Here's the stator. I had to sand a lot out of the inside. There is the chopper inside, right there, with its little blades and everything. I have just wires coming out the side so I can hook nine volt up to it. The clearance is very small, so it took me a long time to mount the stator so the rotor would not hit it. So let's see if that mounting has held up and nothing has moved since I've last tested it. Alright, let's see how she goes. Actually, let me put this right there and hook the nine volt up. So you can hear we're getting a little vibration. There we go. Not only is it the world's smallest, it's probably the world's quietest, but this camera doesn't do it much justice. It's quiet, but it's not inaudible. It's loud enough for its size and for what it's made out of, and it's pretty cool. So there you go. World's smallest air raid siren made out of two pieces of little PVC pipe, some aluminum, a can, a nine volt electric motor. Amazing what you can do, huh?