||Building an Anemometer
You’re used to feeling the wind. Sometimes there’s not much of it and
other times you wish it would stop. An anemometer is used to measure
- Old bicycle wheel assemblies
- bicycle speedometer
- 5, 2-liter soda bottles
- 1-gallon plastic milk container
- 4-foot wood closet rod
- 3 “L” shaped wood brackets
- drill with drill bits
- nuts and bolts
- fine sand-paper
- wood screws
- twist ties
Read allPrecautionsbefore beginning this activity.
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- Clamp the closet rod firmly in place on a work bench. Drill a
shallow hole in one end of the closet rod with a diameter slightly
smaller than the threaded screw on the bicycle wheel’s axle.
- Be sure the caps on the 2-liter bottles are securely tightened.
Cut off the bottoms of the bottles. File or sand any rough or sharp
ends until smooth.
- Drill 4 holes in the wheel using a drill bit the diameter of the
bolts you have. The holes should be at 0 degrees, 90 degrees, 180
degrees and 270 degrees on the wheel. Drill a second hole 4 to 5
inches next to each of the first ones. It’s important that the
distances be exactly the same for each new hole. Otherwise, your wheel
will be out of balance. You now have 2 holes apiece through which you
will secure a nut and bolt (the screws must face outward).
- All the bottles must face the same direction when mounted on the
wheel. The open ends and top will lay on the circumference of the
wheel. Mark the bottles where the bolts touch. Drill or punch holes
at those locations.
- Put washers on the bolts. (You will now have a bolt through a
hole, a nut on the bolt and a washer on the bolt.) Slip a bottle in
place on the bolts. Reach in the bottle and put a washer on the bolts.
Be careful, in case you left any sharp edges! Then tighten the nuts
in place. Do the same for the other bottles.
- If you have room, you can mount another 4 bottles on the wheel.
- Turn the wheel assembly sidewards and place the axle screw over the
hole in the closet rod. Hammer the screw into the hole.
- Mount and level the anemometer to the side of a shed or construct a
base from 24 x 24 inch by 3/4 inch sealed plywood. L-brackets will
make it easy to attach the rod using wood screws.
- Attach the speedometer to the wheel according to manufacturer's
instructions. Attach it to the closet rod, or anywhere you can see it
well. If it isn’t waterproof, design a cover for it.
- Cut the bottom from a 1-gallon plastic milk container to use as a
rain shield for the axle. Poke holes around the cut end to insert twist
ties. Attach the ties securely to spokes. Plastic sheeting can also
be used to cover a larger area.
- Be sure the axle is accessible so you can oil it periodically.
- Take readings several times a day, more often as weather changes