Levers

being a person who has always taken interest in music & art, i am even more fascinated by those mechanisms which help us make such things. for example, the vandercook printing press remains probably one of my favorite mechanisms ever made. also, i grew up with a piano in my household and have, for my entire life, been in love with this musical interface. in recent years i have fallen in love with the sound & size of toy pianos, and was fortunate enough to recently have one bestowed upon me as a gift. being the "take it apart" kind of guy that i am, i unscrewed the lid and flipped it over, upon which all of the keys and levers fell out. it hadn't occured to me that none of them were fixed in place or attatched to anything, but now it makes sense. so how does it work?



sure enough, each key is a lever, in fact each key is two levers, one pressed by the user, and the other (the hammer) to strike the key.

where F1 is unknown, and F2 is fixed (equal to F1)

Gears

A project that I made as an undergrad student was a handmade book that was an instruction pamphlet on how the book was built. The book itself was actually one giant piece of paper with all the pages printed on it, and then folded together in a kind of origami accordion. The book actually showed how it was meant to be taken apart, and then interwoven in a zigzag through a series of wooden dowels on a circular piece of wood. The circular base could then be spun like a zoetrope would allow the viewer to see each page of the book in a "persistence of vision" sequence revealing an animation of the book being assembled and taken apart.

The biggest problem with this piece was it took one person to operate the spinning mechanism, and another person to watch it. What it needed, was was a hand crank on the side that would be geared to the rotating base, and allow the viewer to easily spin the zoetrope by hand, and not need assistance...

Since that project is in a garage somewhere in Washington state, and I am in new york city, I can't very easily recreate it, however, I did play around a bunch with lego gears and had a lot of fun...

Hoodie Power

In the spirit of sustainable energy, fellow ITP student Gilad Lotan and I worked on a circuit that would enable the wearer of a hooded sweatshirt to light small embedded lights, using the movent of the string through the hood. The concept behind this comes from that of a "shake powered" flashlight, which uses a solenoid like motor coil and a magnet to pass back and forth inside of it. The idea is to transfer the kinetic movement of a magnetic field through the coil into an electrical signal which is can then be used for a light.

For the prototype that we built, Gilad and I took a black plastic tube, and made coils around the outside using enamel coated wire. Below is an image of us making one of the coils using an electric drill.





We experimented with several different guages of enamel coated wire, and eventually settled on a wire that was much thinner than the wire in this photograph, the only reason we didn't start with it is because I had assumed that we needed continuity across the coil, but it turned out that it's fine without continuity to induce electrical current. That concept alone was a hard, but rather useful lesson in the flow of electricity. By stacking several coils, connected in paralell, we were able to up the "juice" to an acceptable level. The circuit itself is just the coils, each attatched to a diode bridge (as shown on the previous post) and then into a capacitor. We also have several groupings of 5 strong magnets in various places on a string that runs through the center of the tube. As the string is pulled back and forth, the coils induce an alternating electromagnetic current, which is then changed to a DC current stored as a charge in the capacitor.

Gilad has included a diagram of how the coil induces current on his BLOG, as well as the figures on the millivolts we were harvesting through the transfer of energy. Also there is a great video of our early prototype in action!