H. P. Friedrichs (AC7ZL) Homepage
Marvelous Magnetic Machines
My grandson Kaden watched with great interest as I built the motors that appear in my book, Marvelous Magnetic Machines. In fact, he told me that he wished he could have one. That wasn't possible, at least not at the time, because I was still in the process of preparing illustrations for the book.
However, as his birthday was just around the corner, I decided to build him his own, one-of-a-kind motor, based on the projects in my book. This particular motor does not appear in Marvelous Magnetic Machines, but it does give you a good idea of the type of machine that can be built using the ideas described in the book.
Here is a three-quarter view of the completed motor. The base is scrap metal, a slab of 1/4-inch aluminum. The walls of the crankcase are aluminum castings that were salvaged from the head actuators of a couple of scrapped DEC disk-pack-type hard drives.
The motor is driven by the cylindrical solenoid at the top of the motor.
Here is a view from the terminal end of the motor. The binding posts and the bracket they're mounted on were salvaged from some scrapped instrumentation that I picked up at a ham fest. Notice the pretty brass feet? Those are valve bodies from a set of four discarded air valves.
This is a closer look at the crank on Kaden's motor. The crank was made from a brass gear extracted from a scrapped fish-finder. The flywheel and the bronze bearings it rides on were salvaged from a junked VCR.
Motor timing is accomplished with a leaf switch that is triggerd by the movement of the crank. There is no separate timing cam. The threaded hex standoffs are simply used as nuts to secure the leaf switch stack.
Here is a top view of the completed motor. Notice the vent hole at the top of the solenoid. The motor speed was limited until I enlarged the vent hole with a drill bit. A solenoid plunger can move a surprising amount of air.
Here is a parting shot of the completed motor.
(initial - 10/17/2011)
(last update - 04/22/2021)