These pages will describe the build process.
I finally managed to get around to winding the last of the coils. That was probably the worst part of the build so far. It's just so damn boring and makes your fingers ache.
Now that that part is over, I'm putting the charge controller and anemometer on hold for a while. I really want to get the turbine up in the air as soon as possible. Any spare time I have, when I can't get out to the garage will be spent on the blade CAD tutorial.
The charge controller and anemometer have some issues that need ironing out and I don't want to get side-tracked away from finishing the actual turbine. Hopefully I'll be able to get some cloth and resin over the next few days, and be able to make a start on casting the stator and the magnet rotors.
Ok, so I got impatient and ran out to get some cloth and resin. So now I'm equipped to cast the stator. For the mold I marked out the pattern on a piece of 1/2" plywood and cut it out using a jigsaw. This part wouldn't fit in my CNC, and it doesn't need to be too precise, as long as the coils and magnets line up properly once it's finished.
For the base of the mold I used an old piece of worktop. Being sturdy and flat it seemed perfect. The pattern I'd cut out earlier was given a coat of varnish to seal it, and then screwed down to the piece of worktop. I also cut a 5" circle ( painted and varnished), to place in the centre of the mold. This will leave a hole in the centre of the stator when it's cast, where the hub studs rotate. Now that I had the mold assembled, I needed some kind of release agent so that I could seperate the mold from the stator after casting. The only thing I could come up with that was easily available was vasaline. So all of the mold surfaces got a nice coating of vasaline. Yuk. I then placed a layer of the fibreglass cloth in the bottom of the mold and set the coils in place. I checked the alignment of the phases to magnet spacing, with the magnet spacing jig I'd made a while back. Everything looked good so I poured the resin in. I didn't take any photo's of this bit because I wanted to get it poured, and the mold closed before the resin started to set. Once I was happy that enough resin had been poured in, I screwed a board over the top of the entire mold. This board was also coated with vasaline on the under side to prevent it sticking to the resin.
This is the stator as it came out of the mold. It released very easily, so the vasaline had worked. The only problem was that as the resin cures, it generates a lot of heat. This had caused the vasaline to become very thin, like water, and it had crept into the stator in a few places. This will be cleaned out and small amounts of resin added in these places. The stator needs a general clean up around the edges where some resin seeped out. If I do this again, I'll try a different approach. It could have come out better, but I was pleased that it came out at all. I'll patch up the few small voids and give the entire stator another coat of resin just to make sure it's all sealed from the elements. I may even give it a coat of paint.