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Last Friday George, Scotty, and myself took off from here (Colorado) for the 1150 mile trip to Custer Wisconsin to teach the homebrew wind turbine workshop for the MREA (midwest renewable energy association). We took my trusty 1966 Volvo 122S Wagon, loaded with about 500 pounds of tools and materials. I had much of the stuff (magnets, wire, steel, big tools) delivered there before our arrival. Pictured above we're stopping in Adair Iowa after the first 600 miles to have a nights rest. The car looks a bit heavy in the pic... and it's still missing 3 adult males! The Volvo ran great save one minor break down in Nebraska when the little cam follower on the points broke off. No big deal - I always carry an extra distributor, fuel pump, carb parts, spare tire... about everything we'd need save rod bearings.
George kept fresh flowers on the dash most days. Pictured above were cruising at a 'safe and sane' 80 mph. I drink lots of coffee when I drive.
Saturday we drove about 300 more miles to North Eastern Iowa to help TomW assemble/raise his 12 foot diameter wind turbine ~ and ~ we had a very fine dinner when the work was done. That went well and it seems so far as though his turbine is working nicely.
Pictured above Tom's turbine is up on it's tower. We built that machine at a workshop here last August, I delivered it to Tom last Nov.
We got to Stevens Point Wisconsin on Sunday afternoon. There was no real shop, but we had a garage to work out of and a 1600 square foot tent next to it. We spent the afternoon setting up tools.... figuring out what else we might need that wasn't there, building workbenches etc. The workshop started Monday morning - we gathered in a classroom at the MREA and introduced ourselves to one another, talked about wind power basics and what was to come. Pictured above we're just getting started in the tent winding coils. We had 17 students. Lots of fun getting a bunch of adults together with power tools, pipe, lumber, magnets, wire - it reminds me of 'junkyard wars' a bit. Also quite cool about our workshop this time... we were right under a 30 foot diameter Jacobs 20kW machine that I figure powered our whole workshop!
The plan was to build 3 machines, 7, 10, and 12 feet in diameter. I brought nice water jet cut parts for the smaller ones. The 12' turbine was to be more challenging and built completely from scratch. Pictured above George is showing how to cut out one 15 inch diameter magnet rotor with the torch. Garry did a fine job of cutting out the second one.
Also challenging this time... we had no MIG welder. It's much easier to teach folks who've not welded before to use a MIG welder. This time we had an old Lincoln 'buzz box'. It worked fine.
More magnet rotor work in the picture above. Each magnet rotor needed to have a big hole in the center, and 6 holes around the inside... because such holes look cool, and they may improve cooling - mostly they provide finger access to the inside of the alternator which is nice for assembly. So, lots of work with hole saws!
Pictured above is a finished magnet rotor. Quite a lot of work but it came out very nicely with pretty good precision.
Kevin did most of the metal work for the 12 foot machine - and at the end of the workshop it was his for the cost of materials. He lives off Grid in Wisconsin and has use for the wind turbine.
Building the magnet rotors was fun, as usual. Nobody got hurt but a couple magnets got chipped and a few got stuck together... and some errors were made in placing them. At the end of the day all the magnet rotors came out fine.
Scotty's blade factory plugged along throughout the week. All the blades came out very nicely.
Pictured above the back magnet rotor is assembled to the hub. I didn't post pics here (because there are already too many pictures) about banding the magnet rotors with stainless steel. WE normally do this, and we normally MIG, or TIG the bands together. The band that goes around the rotors is a bit short, and then we heat it, and let it shrink onto the rotor. This time we had no MIG or TIG welder and tried silver soldering the bands together. They came out beautifully... it's a very nice way to do it.
An interesting side project came along during the workshop. About 5 miles away there was a Proven 2500 (12 foot diameter machine) that was not working. Story is (I think) that the bearings failed and the magnet rotors rubbed on the stator long enough so that they wore into the coils and the machine failed. Josh (the installer) ordered new bearings, stator, and magnet rotors for the machine. He installed the new parts, put it back on the tower and it wouldn't run. So he took the machine back down and brought it to the workshop hoping that it could be repaired. Turned out that the new stator was defective. We found a used stator, installed that - and it worked fine. The picture above is the Proven wind turbine with the front magnet rotor removed.
Pictured above is the 'old' Proven stator that the magnet rotors had rubbed into. It reveals how the thing is wound. The Proven has a laminated steel ring in it, and the coils are wound around it toroidally. The magnet rotors each have 8 (I think) huge ceramic magnet and it's assembled so that like poles face one another. All that steel in the stator, it's fairly dangerous to install the stator in this machine - it's very attracted to the rotors and there are no jacking screws. Josh hurt his hand pretty good in the process of putting this machine back together.
It always amazes me at these workshops how everything seems to come together at the same time and we never have time to spare, but we always get everything done. Above they're assembling the blades for the little 7 foot turbine.
After the end of the day Friday some of us hung around and tried to get a sort of power curve for the 7 foot turbine using a right angle drill, tachometer, bathroom scale and some meters. Not sure it was very scientific or useful data but it was fun!
Saturday we finished all the alternators and got all the blades assembled to their hubs. Above they're finishing up blades for the 10 foot turbine.
It was a good group of talented / fun people! We shot this picture a couple hours before the end because some folks always have to go early.
Above is the little 7 foot turbine, it will be used for education at a nearby indian reservation.
And there is the 10 foot diameter turbine. All the machines came out really nicely.
There's the Jake that powered our 'shop'
The last thing we did on Saturday was to weld an adaptor to my spare tire that allowed us to 'bench test' the 12 foot turbines alternator off the rear axle. We used the tachometer, a rectifier, and 4 car batteries to get a sort of power curve off it. We ran it right up to 4kW output for a bit (it gets hot there though). Lots of fun!
At the end of the day on Saturday some of us went to Central Waters Brewing company and celebrated a good workshop! It was loads of fun - everything worked out fine. We left for home the next morning and got back Monday with no problems. Thanks to all the students and the MREA for making so much fun!