These
blades have been extensively tested under a rather large variety of
wind and weather conditions. We even compared them to a commercial set
(brand will go nameless) and we blew them away... Gradually over a
period of time we just got it right! They are well sized for a
variety of small Generator or PMA applications. what follows are
some random thoughts as to there best operation.
1) they
will work just fine the way they are, Great precision we have
found is NOT required for success, but that is not to say they will not
benefit from additional sanding and or balancing just do not change the
overall geometry. feel free to round the leading edge and taper the
trialling edge, you are creating an airfoil, like an air plane
wing...
2) PAINT THE
BLADES.... any kind of cheap spray paint will work, but I am a big fan
of the Rustoleam brands. White is the least visible. This will
dramatically increase there lifespan in the weather
3) Make a hub
from an old metal circular saw blade or even a nice flat steel or
aluminum cooking pot top they have the perfect hole in the center ready
to go
4) Drill the
holes about a half inch in from the leading edge, you can go a Small way in
either direction as in more pitch for less wind and less pitch
for more wind, you actually can do this without a drill using a
soldering iron or hot poker
5) Get them at
least reasonably evenly spaced, use a protractor or even a string,
while I actually have run some horribly mismatched setup ,
one technique that works is measuring from tip to tip of your blades,
if they are the same then your good to go!!
6) PLEASE be
careful the whole wind thing is full of hidden dangers. While raising
the tower if the blades start spinning AND hit you it WILL NOT BE
PRETTY THEY SPIN FAST AND ARE DESIGNED TO SPIN UP FAST.. I
was hit in the head once, it hurt allot and ruined my whole day
ALSO a warning; when you decide to make your own blades using these as
a template.. be careful, people HAVE already been hurt cutting these on
a table saw.......
7) How long
should they be? Well this is a good question somewhere between
24inch an 30inch is just about right for most setups, The longer
they are the more torque but the slower they spin and and the shorter
the more speed...Your mileage may vary of course..
For more on the history and theory behind these blades please check out
my Micro wind power page
