My friend, John, asked me to contribute gyros to the Northern Utah STEM Expo at the Davis Conference Center in Layton. So as I made my mental plans to cobble together a couple of classroom sized demonstrators, I thought about what a teacher might want.
Something simple. Something inexpensive.
My first stop was the Deseret Industries Store at 435 Wall in Harrisville. I knew they had plenty of used bicycles for cheap. They sometimes have single wheels if you ask the manager. But even if you buy a whole bicycle for just the front wheel, you are probably paying around $5.
The trouble with the wheels is that, very often, the bearings are gummed up or shot. I grabbed what looked like a good one, removed the front wheel, and tried it. Yep. Too much friction. I visited my favorite bike shop, Bingham Cyclery at 1895 Washington Boulevard in Downtown Ogden on a slow day. They were more than happy to tweak the bearings and greatly reduce the friction and, since I was a good customer with a good cause and it only took a couple minutes, they did not charge me one cent.
When I was at Deseret, I had picked up a handle for a couple bucks. Probably from a hoe or shovel? It was very hard wood. I cut it into pieces to make a handle. I also notched a groove in one handle with a power grinder perfect sized for a length of clothesline. I drilled holes in the end of each and affixed them to the axle with gorilla glue. Read and follow the directions and that stuff will really stick things together! But it does foam up a bit as it sets, so make sure it doesn’t get near the bearings!
An old drill bit through a trainer wheel (also from Deseret) and stuck into a portable drill gave me an easy way to spin up the wheel.
Have the student hold and feel the wheel before you spin it so they can feel the difference after. You can spin up the wheel and hang it from a piece of clothesline for a dramatic effect. A turntable to stand on while playing with the gyro makes a good angular momentum demonstrator. But I have yet to find a cheap, low-friction lazy susan.
Consider smaller wheels for ease of use and greater safety by smaller students. Pump up the tire and add wheel weights (see photo) to help increase the gyroscopic effect.
I’ll post this now for the teachers at the conference and then add some photos later as I get time. I’ll also talk about how I used the entire front end of a bicycle for my other gyro demonstrator. And I’ll also mention how a teacher might use the bicycle wheel gyro to explain their properties and uses. My favorite is how they are used as speedometers in missiles.