Uwe Oehler has written a simple program that prints out fold-up paper templates for the conic sections that make up the reflective surface of a Fresnel mirror. Cut the templates out of cardboard, cover the cardboard with aluminum tape, fold up the sections, and apply them to a flat backing. Even the relatively simple, five ring, 59% coverage reflector shown in the video will burn holes in construction paper under modest sunlight.
Check out this elaborate page-turning Rube Goldberg machine from Brooklyn area maker Joseph Herscher. The inclusion of fire and trained guinea pig really makes this one stand out.
Here’s yet another delightful mechanical curiosity from among Nikola Tesla’s nearly 300 known patents. Shown above is the sole drawing page from US patent #1,329,559, “Valvular Conduit,” issued 1920. You may have to stare at the upper section, for a moment, to figure out what’s going on: Flow from left to right, as illustrated, is against the valve’s bias—the stream is broken up and diverted in circular paths that return to interfere with each other. Flow from right to left, however, is not so impeded.
This model by Bohr Institute physicist Sascha Mehlhase does not, of course, represent the whole Large Hadron Collider, which is a huge circular underground accelerator. Even at minifig scale, such a model would be enormous. Rather, it represents what is probably the most iconic part of the LHC, the ATLAS detector (Wikipedia). Dr. Mehlhase reports 80 hours of work in the build, about evenly split between design (in software) and physical assembly of its almost 10,000 bricks. [Thanks, Rachel!]
We covered Flickr user yamamo2’s (and his father’s) first high-performance double pendulum build back in 2009. The first version would swing for about 10 minutes, without added energy, after being started. The latest version swings for fully twice that, as the embedded video—all twenty-two minutes of it—thoroughly demonstrates. I haven’t seen any info about the design changes required to achieve this level of performance, unfortunately.
Longtime MAKE pal Raphaël Assénat wanted to recycle his stash of anti-static bags for component shipping, and built an improvised heat-sealer to do it. It’s just a step-down transformer, some current-limiting resistors, a momentary switch, and a resistance wire made by uncoiling a compression spring.
Neat idea from Instructables user Random_Canadian, whose mini metal lathe and homemade plastics extruder we have recently featured. His take on the classic physics toy uses five glass marbles, each illuminated by an attached LED and suspended by the wires that power it.
