Here is something that might be of interest to readers of GEM.
It’s a wind charger that I built in the late 1920’s before
Rural Electrification and used for quite a number of years. It was
mounted on a 40 foot windmill tower using an old windmill head with
crankshaft and wheel removed, and a piece of shafting turned down to
fit Model T front wheel bearings clamped in place of
a crankshaft.
The generator was 6 volt with third brush set for maximum output
and was driven from 18 inch V pulley. Propeller was made from a
piece of fine grained fir 2 by 8 inches by 8 feet long. Pitch was
about 6 to 1 on outer 2 feet gradually changing to about 4 to 1
near the hub. It would charge in a very light wind and supplemented
the generator I drove from milking machine engine to provide
current for lights around the farm (6 volt car headlight bulbs),
radio, and a home brew electric fence. Propeller should be
perfectly balanced and given several coats of hard drying spar
varnish. Even then there will be considerable erosion due to
running at high speed. It would sometimes vibrate when wind
direction changed suddenly. This however was not due to being out of
balance but to gyroscopic effect. A revolving contact was provided
at bottom of mast pipe so it could follow wind direction without
twisting up leads to battery in house. Generator cut-out was
mounted on charging panel along with ammeter and could be shored
around for motorizing and testing of generator.
I built several of these and also several neighbors built them
and all were very successful. Eventually I replaced the original propeller with one having a different pitch, which I found to work
better. Some need for speed control may be found necessary,
depending on what windmill head is used, but I found that by
setting the counterweight partly out on a pipe proved to be ample
in this particular case. An alternator from a modern car I would
imagine might be used with still better results. The speed step
ratio on this particular one was 6 revolutions of generator to one
of propeller.
