Homemade Anemometer

[Bobcat]

I ran across some plans for anemometers that use a bicycle computer to measure the wind speed. Looks like a neat idea. I have used bicycle speedos on motorcycles and bicycles and they're neat little rigs. No reason why you couldn't use one to measure wind velolcity.

Anyone built one or bought one and use it?

[Ian McColgin]

Just gotta allow for voltage drop on the wire down from the masthead.

[teresajude]

Just gotta allow for voltage drop on the wire down from the masthead.

Actually, you don't. The way most bicycle speedometers work is they have a magnet mounted on one of the spokes. This magnet passes by a reed switch mounted on the fork. The computer simply counts the pulses and works out the speed of the bicycle based on the wheel size you put in.

You would have to calibrate the anemometer, but that should be doable. Honestly the hardest part of the project would be correctly balancing the spinner (the magnet only gets mounted on one side). I don't see why it wouldn't work.

Wayne

[Ian McColgin]

Ah, I was thinking of the generator type that measures speed more than the mechanical unit that in my limited experience only measures distance.

[teresajude]

I think they have gone away from the generator type to the pulse-based systems I mentioned above. This is probably because the electronics to convert pulses to something understandable have become so darn cheap.

I have no idea what use "distance" would have on an anemometer.

Wayne

[Bobcat]

The easiest way to calibrate the cyclocomputer is by trial and error. You take a guess at the setting, which is based on circumference, and then mount the rig on a vehicle on a dead calm day. You use a speedo or GPS to see if it cyclocomputer is accurate and then adjust it.

On my motorcycle, I checked my settings against a GPS and one of those readerboards that show you your speed based on radar.

[Paul Scheuer]

"...the hardest part of the project would be correctly balancing the spinner (the magnet only gets mounted on one side..."

No Problem -

Mount two magnets and work out the math

[PeterSibley]

"...the hardest part of the project would be correctly balancing the spinner (the magnet only gets mounted on one side..."

No Problem -

Mount two magnets and work out the math

Mount 2 weights... one of which is a magnet .