by Crimethinc. Workers' Collective
Available in 284 free installments
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When I was twelve, my friend David demonstrated something to me; you should try it too. He pinned a needle into a piece of paper as if it were a lapel, so the sharp end extended past one edge of the paper. He turned his record player on and, holding the paper up, allowed the needle to drag gently in a groove. Led Zeppelin II rose faintly but clearly out of the piece of paper. I was dumbfounded.
But there's nothing too crazy about it. If you want to talk about crazy, crazy is getting sound off a compact disc! A record is analog. In the case of a record, analog means that the texture inside the groove fluctuates the same way air molecules moved in the
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Field Notes
Make a Bicycle into a Record Player
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recording studio when the music was played, and the same way your eardrum vibrates when you hear the sound. The surface of the record is the texture of the sound. The only trick is making the leap from one medium to the next. The needle David used was tiny enough to fit inside the groove. The paper it was stuck into had enough surface area to put those vibrations into contact wdth enough air that it would be audible. Simple shit. Fifteen years later a good friend and I locked ourselves in an abandoned ofRce with food, water, a shit bucket, tools, Zegota's first record (with "Bike Song," natch), and, of course, a bicycle. With the latching of the door, we vowed not to leave the room until we had played that song on the bicycle. We could try this because we knew any piece of paper and any needle could make it possible. Our job was simply to make a machine that could turn the record at a steady speed and an apparatus to hold the needle in the groove while the record turned.
Our speaker cone was made of paper and glue. A standard sewing needle was pinned into the end of the cone and superglued in place. The angle between the needle and record surface was around 45 degrees.
Our record player was vertical This made the weight of our paper cone easier to deal with, because most of it was supported by a hook. The cone was further supported by a few stabiHzing threads that prevented it from flopping to one side or another.
We made a Masonite platter, which we attached to the wheel of the bike with threaded rods, nuts, and washers. We used another threaded rod as the center post. We kept the record in place using a vnng nut and washer.
We isolated the hand-crank apparatus from the turntable and cone by building the record player in two parts. We decided on separation because in our first attempt the vibration and jiggle caused by hand cranking made the record skip. After splitting the machine in two, the crank side could be wobbly and the record side would still spin
clean. We connected the two halves with a thin rubber belt. The pulley on the crank side was fabricated from scraps; the pulley on the record side was a 27" bicycle wheel with no tire. We made the belt from thin strips of inner tube.
At first, the belt had trouble staying in the trough of the pulleys. It would gradually cHmb up the side and jump over the edge. We solved this problem by sewing the flat belt into a tube.
Gearing the machine was important. We wanted to be able to turn the pedal at a comfortable speed and still have the turntable going approximately 33 1/3 RPM. It turns out that is a really slow speed for a hand to turn. That's why we used such a big pulley with such a small pulley. We coupled the 27" front wheel with a 10" pulley that we cobbled together from scraps and fixed to the bottom bracket where we took off the other crank.
Being made of bike parts, the entire drive train weighed very little. That seemed good at first, but it wasn't. Low mass means low inertia, so the record could change speeds quickly in response to slight changes in cranking speed. To add mass, we ran a chain from our crank pulley to the sprockets on the back wheel. We froze the sprockets in place, as on a fixed-gear track bike, so the back wheel fimctioned as a flywheel. The flywheel smoothed out the inconsistent power of hand cranking, making the pitch easier to control. It also allowed you to stop cranking for a moment or change hands without too much drop in pitch.
You might break through this technological barrier, but we found that old records played louder and tracked better than new records. This is because the groves are deeper and more widely spaced.
Make a Bicycle into a Record Player
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