The following are the two "squirrel cage" Vawts I've been working on lately. I think they have alot of promise. Even though they are my own specific design, squirrel cages have obviously been around forever. I have seen one made out of sheet metal, but never 4" PVC "drain/sewer" pipe and 3/4" treated plywood. I quarter saw ripped the 4" PVC pipe with my table saw. So thats 4 pieces per pipe. Each piece is only 3 inches wide. This is 'solid' wall pvc, so it is very 'bendable' and "snaps back" well, which is nice.
The first two pictures are of the small Prototype Vawt-- it has 12 blades and is 18" diam. x 39" high. I really like what i am seeing so far from the testing!
The normal generating rpm range of it is (or;will be) 200-600 rpm. Right now it is attached to a high rpm treadmill motor , so it does not reach 12v cut-in to generate useful power. I may or may not make an alternator for it. It was really only the test prototype. I kept the wires 'shorted' and the rpm looks to be the same as when I allow it to freespin! It just survived what had to be at least a 70mph wind during a terrible thunderstorm last week. It kept perfectly steady and as straight as an arrow and was probably going 1000 rpm with the wires shorted together!! It was AMAZING as I watched the whole thing happen from the window. So it probably has twice the torque of my 4' hawt in the 100-600rpm range. When I short my 4' hawt treadmill motor/generator, it takes over a 40mph wind to turn it!!(or;to break it free from stop and/or stall)
And now... comes the pictures of the 'Real' one. I have named it the "VERTIGO -SC/100".
It better do at least 100 watts! It has very nice torque.
It is mounted to my small trailer hub alternator. (But the Stator is not done yet. Monday, my wire will FINALLY get here, and I will make the stator!!)
It is the same quarter sawed 4" PVC as the prototype. It is 2 feet Diam. x almost 5 feet high. (2" less than 5', because the 10' long pipe has a 'flaired out' 4" part on one end. I cut that off.)
So it is technically 4' 10" high. There is NO center pole in the middle. It is totally supported by the 24 blades. The proto has no center pole either. It is quite strong and actually can bend if it has to. Here is the template. Now I can make more quickly if it performs well!
You can see the angle I chose for the blades. It is my current theory that the wind flows into and around the center and 'swirls' fast and actually EMPOWERS ALL the 24 blades forward, for maximum TORQUE per revolution!! (unlike most if not all other VAWT types) Also, the air resistance is very small on the opposing side of the rotor since the blades are so close together.
The bottom is the one on the left and it has a DOUBLE stack of 3/4" treated plywood glued and screwed together with Waterproof wood glue. Yes, its heavy, but it gives alot of extra support for the blades. This big rotor weighs about 45 lbs. The small prototype rotor only weighed 14 lbs. The small hole in the middle of the top helps with air flow to get more power in higher winds. (I believe)
If the treated plywood don't hold up, I will then weld up all steel centers and no wood. But right now I can see what kind of power I will get out of this rotor.
This is how I 'centered' the whole cylinder shape. I screwed the top on first. Flipped it over and only put one screw in each blade at the bottom. Then kept pushing it 'square' as I put the second screw in each blade. Understand?
These are only ugly (not perfectly straight) testing poles. I will mount them to strong 3 or 4" steel poles painted white real and concreted into the ground real soon. (probably only 8-10 feet high)
I know there is better winds up higher, but I am going primarily for 'looks'.
If the VERTIGO-SC100 does what I think it will, I will make a second one before winter. I am very excited about the speed and torque of these. As soon as I get the Stator done next week and I get the WATT results, I will post more pictures and info!! Feel free to give Any comments, questions, or suggestions!.