Lenz's Law 27 July 2016
I saw a really fun device called Feel Flux which demonstrates Lenz's law and decided to build one myself as they are rather expensive. I acquired a 1" neodymium ball magnet from a guy in China for about $14 and dropped it through a piece of bronze thick walled tubing. A total dud - it fell through as though dropping through air. Which I guess it was. I need to ponder why the bronze didn't work, because as far as I am concerned, it should have. Undaunted, I bought a length of 2" x 6" tellurium copper rod for about $40 and machined out two of the below devices. There is a shallow groove around the middle, and I cut a piece of leather to give it a better feel. TeCu has really superior machining properties to pure copper and the additional Te did not kill-off the Lenz effect as bronze did. The ball drops through in about 4 seconds - impressive!
5 December 2018
I obtained some 1" Copper/Tellurium rod which machines nicely, and set upon building a few more of these things for gifts. The 1" version is shown above next to the 2". The smaller model feels better, is much lighter, and makes a good fidget device. I'm including a few pictures of the machining process. This sort of machining is very therapeutic, being repetitious and all.
The rod is cut into 2" lengths, faced off on the lathe, center drilled and drilled to 1/2". Once all the pieces are drilled, they are bored to .53" to accommodate the magnetic ball easily. And the boring leaves a cleaner hole.
I obtained some 1" Copper/Tellurium rod which machines nicely, and set upon building a few more of these things for gifts. The 1" version is shown above next to the 2". The smaller model feels better, is much lighter, and makes a good fidget device. I'm including a few pictures of the machining process. This sort of machining is very therapeutic, being repetitious and all.
The rod is cut into 2" lengths, faced off on the lathe, center drilled and drilled to 1/2". Once all the pieces are drilled, they are bored to .53" to accommodate the magnetic ball easily. And the boring leaves a cleaner hole.
Once bored correctly, or incorrectly, the pieces are faced off cleanly and beveled. Here are three of the seven ready for the next step, which is cutting the outside diameter to accommodate the leather inset.