Do It Yourself Anemometer-Bearing Assembly

This is my latest idea for a do-it-yourself anemometer using a 3.5-inch hard drive motor as a bearing and an inexpensive bicycle computer to measure speed. The original disc platter and mounting ring is used to provide a mounting base for the wind cups. The original inspiration and credit goes to http://otherpower.com/anemometer.html , but my version is a bit different.

SAFETY WARNING: Use the proper protective gear, eg. gloves, goggles, and breathing protection when drilling the hard drive platter. WARNING #2---Do NOT use a 2.5-inch laptop drive because the platter in those drives is made from a type of ceramic material that will shatter and send sharp particles of material into your eyes and hands.


Here's the parts I stripped from a Western Digital WD-40 drive. Other drives might work but you have to use a drive that has a screw mounted motor. Some drives have a pressed motor. Not shown is the motor.

As you can see, I have already marked the points where the wind cups will be mounted. Also, I scored a portion on the edge of the platter where a magnet will be mounted to trigger the reed switch on the bike computer.

Here's a link to a Youtube video of how the bearing is assembled.



Here are a few pictures of how everything is mounted to a 1-inch to 1-1/4 inch PVC right-angle adapter. I hang the bearing upside down to help prevent water from entering the motor housing.

 

Finally, here's the wind cups, or Easter egg cups (yes, I'm cheap), mounted to the platter.

 

In the next part of this write-up, I'll show how the magnet and reed switch are mounted. Also, the PVC mast mounting technique  and calibration procedure will be discussed.