It’s funny how creation and understanding interact. Sometimes the urge to create something comes from a new-found deep understanding of a concept, and sometimes the act of creation leads to that understanding. And sometimes creation and understanding are linked together in such a way as to lead in an entirely new direction, which is the story behind this plywood recreation of the Michelson Fourier analysis machine.
For those not familiar with this piece of computing history, it’s worth watching the videos in our article covering [Bill “The Engineer Guy” Hammack]’s discussion of this amazing early 20th-century analog computer. Those videos were shown to [nopvelthuizen] in a math class he took at the outset of degree work in physics education. The beauty of the sinusoids being created by the cam-operated rocker arms and summed to display the output waveforms captured his imagination and lead to an eight-channel copy of the 20-channel original.
Working with plywood and a CNC router, [nopvelthuizen]’s creation is faithful to the original if a bit limited by the smaller number of sinusoids that can be summed. A laser cutter or 3D printer would have allowed for a longer gear train, but we think the replica is great the way it is. What’s more, the real winners are [nopvelthuizen]’s eventual physics students, who will probably look with some awe at their teacher’s skills and enthusiasm.
Continue reading “Fourier Machine Mimics Michelson Original In Plywood”








For the past few years, OSH Park, purveyors of perfect purple PCBs, put purple stickers into purple padded envelopes in each order. These stickers weren’t really anything special – just a rectangle with one rounded off corner, a gear, and the OSH Park URL. A few months ago, [Laen] at OSH Park ditched these plain purple stickers for something that taps into the same sentiment as the Apollo 13 pogs distributed through Hardee’s kids meals that included a modular Saturn V-shaped pog case and an aluminum slammer embossed on the obverse side with the Apollo 13 mission patch.