hehe, 30+mph winds + gusts =
sweet dreams and flying machines in pieces on the ground
Oddly enough it was the solder joint on one of the copper tube fittings that "let go". Sadly I was @ work when it occurred. I am really torn on the direction to go. I really need to re-do almost every aspect of what I have built, I wanted a "proof of concept" and I did it on "the cheap"; now I want something that will last 10+ years w/o much maintenance. I was VERY impressed with the torque created by the 42+ inch radius; very UNIMPRESSED with my 10ft x 4in PVC column rigidity; absolutely discouraged by a single 1in bearing pair in a wheel hub to handle the deflection associate with a 10ft moment arm....in short, lots to think about. In the end, I have to design/build my VAWT with the understanding it WILL SEE 100+mph winds within 2 years, and it has to be able to handle 150mph winds if I truly expect 10 year survivability. With one wing damaged and my entire central column idea in the scrap heap; I am torn. I am thinking I am going to contact rfrink again and discuss using some of his parts. Using a pair of his wing kits and four of his "tri-star" rotor pieces I think I can achieve the "durability"/torque I am after in the wings, but the central column and bearings are still a major issue. Unfortunately his bearing design simply is not suitable for my application; I need a centrally rotating main column, not a "rigid column", and this complicates using his parts, but this is a complication that is going to persist in any design. I would love to have access to his CNC laser facility, but he has already explained to me that he has no desire to "customize" the parts, and I certainly understand. Two of his wing kits + four of his "tri-star" rotor pieces will run ~$500 + shipping. My ideas for a central column + mast are looking like they will run another $250+. The bearing carriers et al will be mostly labor if I stick with 1in bearings, but I simply do not think 1in bearings are going to prove durable enough, but larger bearings introduce a considerable amount of expense in both labor and materials....Did I mention I am very torn on which direction to go?
The one thing I am 100% certain about is that I absolutely am in love with a large, low RPM VAWT spinning on my landscape. I am very confident I can make such a VAWT provide most of my water needs, both for domestic use and irrigation. I estimate water output will be between one and three ounces per revolution (5 to 15 ounces per pump stroke) yielding about 40-50 gallons per hour in a 15mph afternoon thermal. My "dump load" will be irrigation, and the vagaries of the wind here should more than quench my lawn's thirst :-) BUT Solving the various problems associate with living in a hurricane zone are troublesome. Building the same VAWT for 50mph survivability would simplify things greatly, but 150mph winds are highly probable in any given 5 year period, and survivability is paramount.
SOOOO, back to theory for another few months. Proof of concept build phase is complete; predictably ending in catastrophic failure. I spent ~ $200 on this phase of the project (more if you count vested costs in materials I already had on hand), and I learned a lot. I do not view this as "failure", but rather an important step in the ultimate build process. I do hope others are gaining something from my process. I am right at 2 years into this project, and I have documented all of it in this forum (Thank You Ben). I could certainly NOT have gotten to where I am in a "quick build"; planning things out is very important to ultimately achieving a goal in Renewable Energy.
Something that surprised me was the total weight of the assembled turbine. Obviously the 42in x 1in steel shaft and the Hub are a bit heavy, but for some reason I did not expect the wings/column et al to be nearly as heavy as they are. The wings "feel light" by themselves, but when assembled, not so light! I would guess the assembled turbine is between 75lbs and 100lbs. Putting it up//taking it down is a chore. (Especially taking it down in a 30mph+ wind! The potential for serious injury was present and immanent). The turbine is also VERY unwieldy in the wind, the torque is amazing! The actual installation will be on the roof of my water shed, some 20ft in the air. I really need to spend some time thinking this step through....a crane comes to mind LOL, but I really don't want the potential damage a crane would do to the yard//septic system etc.
Like I said, lots to think about.