Hello everyone
I thought it was time to share some of my recent work as there is a lot going on at the beach. Yesterday I completed the transmission and alternator assembly. I welded up an old hand drill onto a one inch hub to apply some hand crank power and wired a doc wattson to a 125 Ah battery at about 12.5 volts.. Spinning the low speed shaft without the hand crank I could get about 5 watts out of it. The alt is a four pole axial flux with 1x2x0.5 inch on ten inch 1/4 inch steel discs. It has six coils 160 turns per coil wired in star. The transmission is a 2:1 chain drive in a heavy plate steel case.
We tested the system with the hand crank and were getting 20 watts into the battery at about 75 rpm on the low speed shaft (I didn't have a tach hooked up but I was counting/estimating). It looks like the cut in is about 60 rpm. We were easily able to get fifty watts out of it and once I spun it up to 87 watts for a few seconds.
Overall I am real happy with how this assembly turned out. It's certainly the best alternator/drivetrain I've built here in Nicaragua. I much prefer using a single shaft with flange bearings as opposed to the automotive hubs I have used in the past. I am now using one
Inch W Hubs to mount the magnet discs. I get them from princess auto in Canada and bring as many down with me as I can. They make the alt assembly really easy to put together as the hubs are sized for a perfect one inch mag to mag airgap. I could shave them down to tighten that up but out here I have found that small airgaps can get clogged up with sand. I also think that the turbine will benefit from a less
"stiff" load curve.
Anyways I would love to post some photos of what goes on here but I only have Internet access through an iPhone. I don't know of a simple way to post but I am able to email small photos if someone could help by posting them in the thread.
All input welcome
-KBwind
