As mentioned in earlier posts, we got talked into teaching our 'homebrew wind' workshop for Eastern Michigan University near Detroit. It was a 500 level course, for credit. Half our students were profs at the university. For the most part, they had very little experience with hands on stuff. They didn't know the theory behind wind power or the basic physics but they picked up on that stuff quickly. With 12 students and lots of tools, we were hard pressed to get one 12 foot machine built - but it did come out nicely.
This time we didn't have Scotty on board to help with blade carving so I did that bit. Dan Fink was also there to help, as was George, to help with metal work. I must say they had about every tool we could hope for and more... but the condition of the tools was not so good. All the saws had dull blades and were out of adjustment. They had two mig welders, one was not working at all, the other one required quite a fair bit of 'tuning up'. Seems these days, in this country... teaching hands on stuff has fallen out of favor. 'Shop space' at schools is being turned into 'computer space'. Welding and other shop classes are being cancelled in favor of 'IT' classes. Community colleges are teaching classes on 'how to take tests' rather than how to make stuff. I wonder if this has anything to do with the fact that Detroit currently has about 50% unemployment. It was depressing to hear that a kid born in Detroit has about a 25% chance of graduating high school and about a 0.2% chance of getting any sort of college degree. I believe this is the reason they hired us to come there and start with simple theory/physics and follow it through to a functioning 12' diameter wind turbine.
Pictured above George is demonstrating how to use a torch to cut steel rotors from 3/8 inch flat steel.
Above Ben is winding coils for the 12 foot wind turbine. This is a 24 Volt turbine to be installed at the home of one of the students, who is the electrician for EMU (here, I believe it's 'timeless turbines'). So far as I know, he has erected the machine since we left and it's working well. The coils for this one were wound with 4 strands of #16 gauge wire in hand, and 36 turns per coil.
Building the stator mold! The mold for this turbine is 20 inches in diameter, the island in the middle is 8.25 inches in diameter. I believe this is about the 11th 12 foot diameter machine like this that we've built. So far, all the ones that have been erected seem to be holding up fine and producing pretty well.
Above is a bit more magnet rotor cutting... some folks really take well to this stuff even with no previous experience. Others don't ;-)
Pictured above Jonathan is carving blades with the draw knife. At this particular workshop - we allowed for no power tools except the band saw just to cut the profile of the blades. When finishing the blades, sand paper was not allowed either. All the blade work was done with hand saws, drawknives, hand planes, spoke shaves, and they were finished with scrapers.
That said... I did not even bring scrapers and they didn't have any there, so I showed them how to sharpen the backs of the hand saws to be good scrapers.
This machine progressed a bit more slowly than usual, which was fine... everyone was busy, having fun, and learning stuff. On the afternoon of the 4th day, they were just getting the magnet rotors built.
As with the last couple of workshops this summer, I had them build nice blade hubs out of steel, from scratch.
Ahh... finally the alternator is coming together!
The stator is ready to install!
Pictured above Jonathan and the dean of EMU, standing next to the finished wind turbine.
During the afternoon of the last day, we had time to dyno test the alternator off the back wheel of my car, using a bathroom scale, a laser tachometer, and two 12 volt deep cycle batteries as a load. Lots of fun! After that we loaded up! The next morning we made the 1400 mile drive back home. We've had a couple more good adventures this summer/ fall... which I will post about soon.
