Building a Homemade Crank Organ: Groovy Wheels

The wooden wheels I cut out are used for driving the take-up spool. The larger of the wheels is on the same axle as the take-up spool and it is driven by the rotating action of the crankshaft which is translated through a spring tensioned axle that holds the idler wheel. The idler wheel is fitted with a rubber ring and it uses the rubber friction and the spring tension to keep it in contact with the spool wheel. All of this is eventually hidden in the casing of the organ, and the only way to see it would be to install hinged panels on the case (which I'll likely do) or make the thing out of plexiglass (yuck).

To put the requisite grooves in the edges of the spool and idler wheels (to accommodate the Hoover vacuum cleaner belt/ "tire"), I first put a short machine screw through the small hole I had drilled in the center of each wheel and secured it in place with a nut. The screw needed to be a tight fit, so I kept poking around in my junk cans until I found a couple that were tight enough that they needed to be put through the wheel with a screwdriver.

I then attached the wheel to my drill press using the machine screw as a shank, then - after making sure of the rotation direction - I tried various odds and ends to cut out the groove. I tried a drill bit, a needle file, sandpaper wrapped around a rod, and even a piece of 1/4" threaded rod. The drill bit was too jumpy, the needle file and sandpaper got varnished quickly and didn't remove material fast enough, but the threaded rod worked fairly well. I held the rod parallel to the the wheel and used the threads to cut into the material. My wife brought me a bullet shaped grinding stone from the dremel tool case, and I soon found that this was the best solution, as it allowed for fast material removal and a great degree of control over the shaping of the groove.