Today was a fun/busy day for the most part. We worked on several different projects. To start with, some may recall that last spring (may 8 I think) my digital camera (a 2 year old Sony MVC CD 500) fell off a workbench and died. Its one of those that keeps its pictures on a small CD. I seem to have fixed it yesterday first thing, by simply dropping it about 3' onto a thin carpet. Dropping electronic devices is, for me - one of the best bets when it comes to repairing them. The height from which they get dropped though, and the surface they hit is critical. Perhaps I'll write a book about all this. Tube amps, for expample - should usually be dropped only about 3" onto a hard wooden surface. At any rate, the camera is fixed so I shot lots of pictures!
George showed up early and we finished building the stairs that I'd started over the weekend. Another little bit of the shop done - now were down to a little shelving, and some finish work upstairs.
Once the stairs were done George set to winding coils for a stator. This will be a 9' machine, we'll be bringing this to an SEI (Solar Energy International) wind turbine seminar on Guemes Island in Oct. This one is wound just like a 10' machine, with 140 windings per coil - although were using #17 gage wire. These days I usually put #16 gage in the 10' machines. To fit #16 wire I made the hole a bit smaller and the mould a bit larger. So these coils are a touch on the small side, but I think it'll give us a good cutin speed and reasonable resistance for a 9' machine. If it's too slow we'll open the airgap up a bit.
Here are the 3 phases wired together. I like to wire each phase one at a time. Each one is 3 coils in series.
Then we used duct tape to hold the coils in exactly the right position in the mould. There are lines in the mould that show the path of the magnets, so we can use the mould to be sure the coils are positioned about perfectly.
Once they were all taped in place we used the little fiberglass squares and super glue to hold it all together.
With the superglue/fiberglass on there, the uncast stator is strong enough that we can remove it from the mould.
We cut fiberglass rings 15.5" in diameter with 6" holes in the middle that fit the mould. There will be one on each side of the stator to provide some strength, and to make sure that none of the wires in the coils can break out of the finished stator.
We got the stator done about mid afternoon. It spent about 1 hour in the mould. I like to pull the lid while its still a bit soft, it makes it easier to trim off excess resin. Then I leave it in the mould till it cools so there's no warpage.
While George was winding coils I primed the machine. We welded this one together about 2 weeks ago. They have serial numbers now! (this helps me keep straight which parts go with which machine and keep notes about exactly what we did, how it worked etc... for each machine). This one is #32. #1 was Dave's machine at the caboose. I prime these with an automotive 'self etching' primer which seems to work nicely.
The paint came out nicely. We use acrylic enamel with a hardener - it blows away the spray paint we used to use. Powder coat would sure be nice though...
Scott came over around 4:00 with a radiator from an old Scout. We figured it might work nicely with the little diesel generator we made - hopefully without the need for a fan.
The generator is just bolted to two pieces of angle iron which are driven into the ground near the generator. We put it high above the engine hoping that it would thermosiphon.
Bonnie will also have to live with this thing... here Scott is teaching her to start it. Lots of smoke... I think this engine could use some adjustment, although once running and up to temp it seems to be running pretty clean.
Here's what its putting out... about 60 amps into the battery and the AC end is unloaded at about 125V. The battery that it's charging is quite full at this time or the amperage would be up a bit more. But we ran it for over an hour last night. The radiator/thermosiphon worked out great. The stator never warmed up, and the rectifiers only got slightly warm. I think its quite an efficient charger. The AC end will easily pull 1500 watts it seems - even while it's charging a battery. I have to say, this is the most powerful 2.5hp engine I've ever known.
Matt and Daphne showed up around 7:00 with pizza as usual.
And folks came over to eat the stuff!
The dogs tested the stairs for us - they seem to work fine. They're steep - we decided they are stairs though because the dogs come down foward, not backward. Had they come down backward we'd have called it a ladder.
And there was a bit of dancing although that had to stop, Sage (a blue healer) would not permit that...
