The Mono

I went out to Pittsburg tonight to test the turbine.

I assembled it half by feel, in the dark, until Greg came up with one of the head-lamps that illuminates where I look (better than him having to hold the floodlight on it). I screwed the pipe to a board, clamped the board to a fence, assembled the apparatus and put it up -- first time without even any chains, just the freespinning rotor, to see how it did.

Result: Abject failure.

Granted, the wind direction was erratic; it kept flipping up to thirty degrees back and forth, which meant the blades had trouble maintaining their momentum (change the course of a spinning bicycle wheel and see how much speed it loses). But even when I gave it a hefty starting spin, either direction, in a couple of minutes it had reverted to shifting uncertainly this way and that way, not actually spinning at all.

I put the blades on backward, so the concave side faced outward, and it seemed to do very slightly better (though that may have been my imagination).

My only thought is that I need to check the pitch of the blades, to make sure the leading edge is in the same plane as the face (in airplane terms, make sure it's not trying to "lift off" off the face of the rotor or tilted to "descend" into it). From what I remember from balancing them, though, they're basically planar. So.... maybe it needs a steeper pitch to "bite" into the wind? I really don't know. Everything I know about airfoils said that these blades should have spun at some speed in 15-20 mph winds, and they failed utterly.

The scenarios I expected were: success (thus it goes to the Burn) or failure in that the blades are too small (thus it stays home for a year). I found scenario three: failure so total and inexplicable that I take it to the Burn... because there are lots of wind-power experts there who might be able to help.

It's been an interesting project. For now, I'll focus on getting the bikes ready, packing, and cooking.

So I have been cranking along pretty steadily on this project, and I just stopped to refine my to-do list... it looks like I should be able to complete in under three days *knock on wood*, which means I'll get some testing time and (probably) enough time to paint it, construct a filter for the alternator, and put a dust-guard on the main hub. Here's hoping!

In case anyone wants a glimpse at what still needs to be done, ( here's the list: )

Here's hoping -- even if we don't get it painted or shielded before we go, I expect it will be complete enough to take with us, so long as there are no gross flaws. *crossed fingers*

T-minus 6 days, 21 hours.

So, the project I'm working on is a small wind turbine for Burning Man, to power the RV's battery bank and supplement (or replace) the onboard gasoline generator.

( details... )

Negatives for yesterday:
- Woke up sick -- sore throat, achy. Developed a serious upper-sinus headache over the course of the day.

- Forgot to bring water and got rather dehydrated.

Positives for yesterday:
+ Apparent success in incorporating an elderly female cat into my young female cat's territory (my room). They were ignoring each other only a few feet apart. Yay! (Only slightly marred by the fact that once we moved Fuzzy's things in, it really started to sink in for Charlotte, and she got a little jealous -- but she's really not used to being mad at me, and it'll blow over pretty quickly.) Very quick adjustment period.

+ I went out to get a used car alternator, and right away I rediscovered McHugh's Dismantlers, which hadn't been in the list of places I pulled from the phone book. It's quirky, smells like cats, and the business itself runs like a relic of the 30's... but they're friendly and know what they have.

+ I selected an already-disconnected alternator from the shelf, no pull-fee... it has a standard power socket, sealed bearings on the backside, a lovely pulley wheel which will be easy to connect things to, and turns easily (but not too easily). Price: $25 plus tax. Time: 10 minutes.

+ I went into Berkeley for junk bicycle parts for the gearing system I'm building, and decided to hit Recycle Bicycle first. This is the bike shop I've been wanting for years. Their used-parts section is self-serve, a block of filing cabinets stuffed with serviceable detached bits, sorted by type (and an awesome "miscellaneous" bin with every small part imaginable). I got two hubs, a gear cartridge, and various loose gears for $15... and then they offered me the staff bathroom (with liquid Lava soap) to wash my hands in. WIN.

+ I went on to Urban Ore. I thought I had been there before... I was mistaken. I came out maybe two hours later, and counted myself lucky that I didn't get permanently assimilated by the most awesome incarnation of a thrift store EVAR. I got a tempered glass piece for my solar oven for $3 (normally $20), some square steel tubing for another $3, and knowledge of where I can get more 8" PVC pipe and a marble slab (for filleting fish) when I want them. Going back? Oh yes.

+ I had a very nice evening with eastbaygreg, at least until my cat got mad at me and demanded that I worship her exclusively for a while. (She would play with me, I would pet her, she would purr absently, and then she would look at me -- and her eyes would narrow as she remembered "oh, right, I'm mad at you" and she would stop purring. Lather, rinse, repeat.)



The sore throat is no worse today, and I think that illness is on its way out (pretty typical). My list for today is too long to complete, but I hope to rummage through McHugh's again for a pulley (I need a rotor to attach blades to) and do a bit of paperwork for school. I'm enjoying myself. :)

And yes, I will make another post about how I'm putting all these mechanical bits together.