An anemometer is a pretty simple device. Attach something to catch the wind to a shaft and then count how quickly the thing turns.
|The initial plan was to use this little scavenged (from a tape drive, I think) stepper motor.|
|The motor had a little nylon gear on it, so I decided to make a small hub that the wind cups could be attached to which would then glue to the gear. Simple is good.|
I traced a jar top onto the scrap fiberglass reinforced plastic I had available. Wood would've worked fine too, just not as rain-proof.
|I used a bandsaw to cut the circles out, I did two because the plastic isn't very thick. The belt sander cleaned them up nicely.|
|Super glue and a little weight stuck two discs together to make them rigid.|
|I used a center finder and Xacto knife to score lines to find the center point.|
|The hub had to attach to the nylon gear somehow, so I just drilled a hole the same diameter as the gear...|
|... stuck it in straight and super glued it there.|
|With a solid hub attached to the motor, I used styrofoam cups and plastic knives along with some tape to do a quick test. Not great, the cups are light but flat on the end so they don't really want to turn much.|
|A trip to the dollar store yeilded a set of metal soup ladles. I broke the plastic handles off of them, drilled two holes in each to put small machine screws through, and bent the shafts to make the angle of the spoon face into the wind once they were mounted on the hub.|
|Here's the side view while attaching the spoons.|
|It works! However, as I held it in my hand I realized that the thing had become far heavier than I expected and that the little motor it was mounted to wasn't tough enough to stand the test of time.|
|I found another (much larger) stepper motor from the same tape drive and mounted my hub to it. It mounted with three screws down into the spindle of the motor, so I drilled holes through the hub for those and attached it. It's much more stable now - and the stepper spins easily as well.|
|With the physical part of the anemometer working, it was time to move on to the electrical part!|