Just to save time for anyone trying to improve their fan type anemometer, here's what I've discovered. First, bottom line is the 2 bearings LaCrosse uses for the fan aren't sensitive enough for a fan start up threshold as low as a cup type.
I've removed them and soaked/cleaned them so when reassembled they would let the fan rotate easily from the slightest breeze but still no match for the cup type. (comparing with another cup type anemometer mounted beside). Best I could get was about a 2 1/2 Mph start up speed then would follow the cup speed. Next I tried converting over to a self made cup assembly.
Two issues to deal with here. Not only locating bearings sensitive enough but also the speed difference between the fan and cup hubs where the magnets are mounted. That is, the fan hub spins considerably faster for a given wind speed than the cup style hub for the same wind speed. A 10Mph wind will spin the fan's hub faster producing more pulses than the cup style hub for the same wind speed. I believe a firmware change would be needed for this conversion to work. The bearings are another issue altogether. I'm still searching for a factory or manufacturer for ceramic or Teflon bearings in the size needed for the fan.
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Also see:
http://www.wxforum.net/index.php?topic=11195.msg115176#msg115176 (discovered at a later time).
