~ Notes on Bike Hubs ~
You may wonder what makes our whirligigs spin.
The answer is a bicycle hub. A basic front wheel hub is designed to spin well and fast and last a good long time. I originally repurposed old bike wheels to get their hubs, but when I began teaching workshops and needing so many so often I had to start ordering them new. I wanted to point out that not all front hubs are the same. TYhey all should spin and work for a whirligig but the material it's made of an it's dimensions can vary slightly. Aluminum hubs are lighter in weight than steel but this makes little difference as far as the spinning goes. What does matter is that often a hub is tight and not smooth moving. Hold onto one bolt end an spin with your fingers. It should rotate smoothly and easily.
If it doesn't, it may have a little rubber dust cover over the black lock nut. These aren'y needed for whirligig purposes and they slow down the spin. Just pry it off with fingers or a flat head screwdriver. (see below).
Next if it still seems tight, put one ends lock nut in a table top vice clamp and with a closed end wrench on the opposite black lock nut turn gradually to the left. As you do this, continually stop and spin the hub. Stop turning the wrench as soon as the hub is spinning smoothly and easily. If you over loosen the nuts you will notice a up and down wiggle in the hub that can cause the whirligig to vibrate as it spins. If you experience this vibration in your gig, tighten up the hub slightly.