A logging anemometer too!
I made this using a bicycle speedometer, a (front) bicycle hub, and 3 stainless steel mixing bowls.
The construction procedure is:
- De-spoke the wheel;
- Weld three 8" bolts to one end of the hub, threaded end out (easier if you cut the bolt heads off first);
- Pound a nice curve into the bottom of the mixing bowls (probably not necessary);
- Attach the bowls to the ends of the bolts by drilling a hole in the side of each bowl and using 2 nuts;
- Tape a magnet to one of the shafts to trigger the speedo's reed switch;
- Make some sort of bracket to hold the reed switch at an appropriate position (I used aluminium wire).
- Do the old pole-on-a-truck calibration routine. ;-)
The good part about this is that for $40 or so you can have an anemometer that will (depending on the bicycle speedometer you chose) display average windspeed, odometer, highest windspeed, trip time, etc. The odometer on the speedo I'm using will run to 9,999km, so I can easily leave it for a week between readings.
Some sort of cover over the top of the bicycle hub to keep water out of the bearings is a good idea - I used a small spraycan cap with 3 slots cut in it so that it could be wedged over the "spokes".
BTH
