Brian's Morning Newsletter November 3rd 2009
Pretty slick looking wind turbine blades, huh? Yesterday while Amelia and Austin worked the log splitter, I laid out the blades on the shop floor and began the task of measuring the distance from blade tip to blade tip. Talk about spatial anomalies. Move one blade around the axis by a 1/2 inch to increase the distance between a particular set and of course the other set is affected. The tolerance stated in the Home Brew Power book is 1/4 inch difference. I never could get it there, only 1/2 inch difference, right? I was loaded up on pain pills for my back ache, so after a couple of hours of fiddling with the spacing I screwed it together, figuring there was an additional 1/4 inch tolerance in my measuring technique.
At this point I have several coats of Linseed oil on the blades, with the first three being thinned down to 80% mineral spirits. All the coats rubbed in yesterday were a 50/50 mix, which is still thinner but I slathered it on and let it sit for an hour before rubbing it off. The next question was how to perfectly center a hole in the two 11 inch diameter plywood disks. I settled on drawing a perfect square on the workbench beneath the disk. Then it was simply a matter of drawing lines dissecting the squared lines on the table in a cross hair pattern onto the disk. Bingo. You may not have seen our wind turbine in motion, if you have you'll see the affect of not perfectly centering the disk. It is purely visual, the disk moves in a slightly elliptic pattern.
Hopefully these disks with move in perfect parallel circles. Also, I realized from reading the book, yeah, I read books, there are supposed to be two carriage bolts per blade. I have at least one job at Desertgate today, so I head over to the hardware store and pick those up when I get a break. Oh yeah, the Trooper. I'll not be using the Isuzu Trooper today, not until I put it in the shop and find out what the horrible noise I heard when I drove it last week. More bad news, for my job, anyway, my cell phone didn't get transfered to Verizon like it was supposed to. I called them last night, and found out why: Our credit check failed miserably. Verizon wants $400 deposit. Oh well, maybe we don't need a cell phone after all. Certainly we can't afford to let one of these mega corporations hold our hard-toiled-for cash.
There is something terribly disturbing about that. we don't have enough money to pay our bills, so they, and I use the proverbial "They' want extra money. Anyway, it looks like the end for our long held 454-9661 The Outfit phone number.
Using the 2.5 inch hole saw I was able to set a spare hub assembly into the disk blade set, and then use it as a template for drilling the main turbine hub bolt holes. I figured out what the Otherpower forum's user Flux meant when he sad the hub – tower off-set is where the adjustment for wind swept area is made. If you can envision, the wind is pushing back against the blades with a force calculated by the distance the hub (center of the turbine) is away from the tower center. More blades length means greater wind swept area which in turn means the blades will be trying to move out of the wind harder, to which the tail can only counter with so much force determined by its off set to the tower. I know I can't explain this relationship properly, but it means something to me, and for now that is what is important.
In later newsletters I will show some diagrams of the tail off-set and the hub off-set, and try and try and make it make sense. If I were to look back a year when we began building the turbine housing, I certainly couldn't have told you why the off-set was what it was, we just followed the book. Now I can't speck for Kevin, he may have known all along since he is much quicker with this stuff. One thing is for certain, as I work on this assembly alone (Kevin is sick with the flu) more inroads and correlations to the engineering are coming to the light. Last year I thought, wow isn't it amazing that Hugh Piggot figured out how to setup the tail so gravity makes the turbine track the wind?
Here they are, 1608 amp hours and 1200 pounds of sealed cell deep cycle batteries.
In these hard times shelling out $400 of what is ultimately Nell's paycheck I decided to look up the batteries we bought used. Ah, this makes me feel a little better, these batteries were around $300 apiece new, which I realize was a long time ago, and unlike wine, batteries do not get better with age.
Some kind of coincidence that the mega corporation wants $400 to hold and $400 is how much we paid for these batteries?
It puts things in to better perspective
Moving toward off grid living or lend Verizon $400 so we can pay them $50 per month to make a few phone calls from the car?
Not a tough one to figure
See ya tomorrow