We had an interesting workshop last week (Feb 2010). We were asked to give a 5 day workshop on wind energy at Eagle Rock High School near Estes Park Colorado. Estes Park is, as the crow flies, less than 10 miles South of us here, it's a 75 miles drive though. It's an interest 'non traditional' high school for students who were not doing well in more traditional schools. Most of the students are not from Colorado, but rather come from larger cities across the US (like LA, New York, etc). The campus is beautiful, set on 640 acres in the mountains at about 8000 feet elevation. The school is completely funded by Honda Motors of America. All of the students and most of the staff stay on campus.
We began our workshop on Monday morning, starting with the basics: what is power, what is energy, where does energy come from, what is wind... how do we convert energy in the wind into electricity. The shop space was large, clean and wells stocked with tools. We had 12 students.
We took lunch break every day at noon. Food at the cafeteria there is pretty incredible... mostly organic, very healthy and very gormet. Students that attend this school have a lot to be grateful for, I've never seen such a neat high school. After lunch on Monday we got down to building a 10 foot diameter wind turbine. We started by winding a few coils for the stator. Then we divided the group into 3 stations: wood working, metal working, and alternator fabrication.
Scotty brought laminated cedar blade blanks. Pictured above he's explaining the layout for the blades to all the students.
Issack clipped the leads on the coils and cleaned off the insulation.
Scotty helped Scotty to cut out the profile of the blades on the bandsaw.
Shawni cut out the fiberglass rings to reinforce the stator.
Pictured above all the coils are wired together, almost ready for casting.
Eddie, Issack and Shawni glue the coils together with bits of fiberglass and cyanocrylate glue.
All roughing out of the blades was done with a drawknife. They were finished with hand planes, spoke shaves and scrapers. A bit of sanding was done at the end but very little...
Almost everybody got a bit of welding experience with George.
Pictured above George fixes the welder... we had some trouble with it but overall it worked well. This poor welder has not seen any use in about 5 years and it's been sitting outside under a tarp.
Everybody got to handle the magnets when we built the magnet rotors. Only one student got pinched...
There's the stator ready to cast. This is a 48 Volt machine, each coil has 140 turns of 16AWG wire.
Issack fills the mold with Vinyl Ester Resin. We did this in the garage outside where we had pretty good ventalation.
We banded the magnet rotors with stainless steel and cast the magnets in a mixture of vinyl ester resin, ATH, and chopped fiberglass.
The stator came out nice with almost no defects. Pictured above Diana is deburring the edges with sand paper while Lauren cleans caulk off the magnet rotors.
Julian works towards finishing the front of a blade with a spoke shave.
Diana with the finished stator.
Lauren cut out the tail vane with some sort of strange japanese hand saw.
Scotty and John kept the wood tools sharp.
Chris is a pretty good mandolin player!
At the end of the day on Wednesday they had the metal work all tacked together for the 10 foot wind turbine.
Chris carved one blade pretty much all by himself... it came out very nicely.
Diana and Jeffrey worked towards completing a second stator.
The students have to do KP (kitchen patrol) duties sometimes.... George decided to join them on Wednesday night.
The metal work was primed and painted... outside.
Julian and Jeffrey test the alternator with a lightbulb. At this point it only had the back magnet rotor mounted.
The tail vane was painted with the school emblem.
Chris decided to do some dentistry on himself I guess....
Pictured above the wind turbine is about finished. We only have left to assemble and install the blades.
We setup two jacking screws as a 'commutator' and a piece of wire as a brush and turned the alternator into a DC motor.
At the end of the day on Thursday we layed out the blades and started to assemble them.
Diana, Shawni, and Eddie fit the blades to the machine.
Issack and Scotty balanced the blades with lead weights.
On Friday, we discussed the economics of small wind power.... basically the point was, it costs quite a bit more than grid power, even if you build your own equipment.
At the end of it all, the students had to give a presentation about what they did.. and what they learned, in front of all the students and staff. They did a great job I thought ~ we had a fun week. It's a great community at Eagle Rock! Big thanks to all the students and staff... it was a pleasure to be up there!
After it was all over we went out lunch. I shot the picture above from the window of the car where we parked... this is pretty typical of Estes Park, the elk are everywhere.
