Prototype I: Hand-Cranked Harmonograph
Project in a Nutshell: I created a hand-cranked harmonograph with a set of exchangable gears with different teeth #s so users can create unique patterns and discover the effects of different gear ratios on the pattern outcome. In general, mechanical harmonographs use either pendulums or cranks for oscillators. The movement of a horizontal crank when viewed from the side is the same as that of a pendulum when viewed from the bottom. Both are examples of harmonic motion, and they create different types of curves, often resembling Lissajous curves, which are graphs of a system of parametric equations which describe complex harmonic motion. [Video to be added soon -- at the time I couldn't manage to hold my iPhone and crank the harmonograph both at once]
Concept and Evolution: I originally wanted to create a harmonograph with pendulums, similar to one of Britt's mechanical prototypes. Thus I researched ways to build harmonographs and found many interesting set-ups, some with 2 pendulums, some with three. However, they all had two things in common: the need for heavy weights, and the need for a large table or a large space to set up the harmonograph. While exhibits are awesome and engaging on the large scale, I wanted to seek out something smaller and more confined for my prototype. Furthermore, the problem with weights was, I knew to overcome friction I needed really heavy weights, else the pendulum movement would be dampened too quickly and you wouldn't get much of a pattern and more of a squiggle. Finally, I read an article where a scientist who developed a hand-cranked version he called a pantograph once said, "The [pendulum-driven] harmonograph, generally speaking, is some-what tolerantly regarded in physical circles as a scientific toy, though the beauty of the result never fails to excite admiration ... through begrudgingly. The cause of this attitude probably lies in the fact that science always deals with exact premises and in this the usual pendulum-controlled harmonograph fails lamentably." This was further impetus to develop a different way to exhibit these patterns that is more controlled, and more open to discovery and exploration, in the light of the Exploratorium.
Concept and Evolution: I originally wanted to create a harmonograph with pendulums, similar to one of Britt's mechanical prototypes. Thus I researched ways to build harmonographs and found many interesting set-ups, some with 2 pendulums, some with three. However, they all had two things in common: the need for heavy weights, and the need for a large table or a large space to set up the harmonograph. While exhibits are awesome and engaging on the large scale, I wanted to seek out something smaller and more confined for my prototype. Furthermore, the problem with weights was, I knew to overcome friction I needed really heavy weights, else the pendulum movement would be dampened too quickly and you wouldn't get much of a pattern and more of a squiggle. Finally, I read an article where a scientist who developed a hand-cranked version he called a pantograph once said, "The [pendulum-driven] harmonograph, generally speaking, is some-what tolerantly regarded in physical circles as a scientific toy, though the beauty of the result never fails to excite admiration ... through begrudgingly. The cause of this attitude probably lies in the fact that science always deals with exact premises and in this the usual pendulum-controlled harmonograph fails lamentably." This was further impetus to develop a different way to exhibit these patterns that is more controlled, and more open to discovery and exploration, in the light of the Exploratorium.
Thus I decided to create a harmonograph driven by gears instead of pendulums, because users can directly swap out gears and note the numerical differences in the # of teeth per gear, and how that may affect the outcome of the pattern. It was also smaller, more confined, and more transportable. I was inspired by an old version called the "Wondergraph" to create a harmonograph that also uses gears, but is different in design.
Ideal Interaction: My concept of the ideal interaction would be to have users crank the gear system to create an interesting pattern/curve on paper that they can then keep and bring home. However, to enhance the interaction so the users aren't simply "motors" to crank the machine, the gears are all removable and users can switch out gears of different teeth numbers from 29 to 43. Thus the use has a degree of freedom to explore the effects of different gear size relationships to see how this affects the curve that is produced. Ideally the user would try to make multiple drawings using different combinations from large-small gear pairings to all small gears, to gears with all prime numbers, to gears that are a direct ratio of teeth such as 40-20-40.
Problems and Improvements: One problem I have is with the pencil/pen holder, as shown in the image. I tried to be as resourceful as possible and used a series of rubber bands and screws to hold the pen up. But since then I have prototyped more in the PRL and have laser cut better pen holders that work more effectively. Ideally I want to create a pen holder similar to those of circle compasses that use a bolt and can tightly grip onto a pen of any diameter. Right now with my design, the pen clips in so that severely limits what pens can be used. I wonder if I should optimize for pens or colored pencils/pencils for my final design? (since the girths are different.)
* Another problem I had was the mechanism for easily removing the gears. I want the users to feel encouraged to swap out gears, but the harder it is, the more unlikely they will exert the effort to do so. Right now the user has to twist dowels and slide them between gaps in the harmonograph base, which is a clunky interaction. I will need to brainstorm ways for the 2nd iteration of my prototype.
* For easy addition and removal of drawing paper, I think I will have a system of two or four clothespin clips that grip the paper tightly so that its stable but doesn't require the hassle of taping paper down each time.
* Another improvement for the exhibit would be to create perhaps 2-3 more cranked harmonographs that are based on the same concept of gear ratio, but are constructed differently and have slightly different mechanics. It would be interesting to compare and contrast the behavior exhibited by each. Also this gives me the opportunity to explore building new things.
* Last but perhaps not least, if anyone has better title suggestions than "Hand-Cranked Harmonograph" please entertain me with ideas and let me know in the comments!
Problems and Improvements: One problem I have is with the pencil/pen holder, as shown in the image. I tried to be as resourceful as possible and used a series of rubber bands and screws to hold the pen up. But since then I have prototyped more in the PRL and have laser cut better pen holders that work more effectively. Ideally I want to create a pen holder similar to those of circle compasses that use a bolt and can tightly grip onto a pen of any diameter. Right now with my design, the pen clips in so that severely limits what pens can be used. I wonder if I should optimize for pens or colored pencils/pencils for my final design? (since the girths are different.) * Another problem I had was the mechanism for easily removing the gears. I want the users to feel encouraged to swap out gears, but the harder it is, the more unlikely they will exert the effort to do so. Right now the user has to twist dowels and slide them between gaps in the harmonograph base, which is a clunky interaction. I will need to brainstorm ways for the 2nd iteration of my prototype.
* For easy addition and removal of drawing paper, I think I will have a system of two or four clothespin clips that grip the paper tightly so that its stable but doesn't require the hassle of taping paper down each time.
* Another improvement for the exhibit would be to create perhaps 2-3 more cranked harmonographs that are based on the same concept of gear ratio, but are constructed differently and have slightly different mechanics. It would be interesting to compare and contrast the behavior exhibited by each. Also this gives me the opportunity to explore building new things.
* Last but perhaps not least, if anyone has better title suggestions than "Hand-Cranked Harmonograph" please entertain me with ideas and let me know in the comments!
Other ideas: An aside, I discovered that the arms I made could also be used as a pantograph in this interesting manner (below.) I don't think I'll include this in the final exhibit design because it doesn't seems directly related to the harmonographs concept, but I thought it was interesting and wanted to leave it here. It reminds me a bit of Alice's "Drawing Watt" mechanic arms and how you can do so much with something so simple:
Prototype II: Spirograph
Project in a Nutshell: I created a spirograph (spirograph and patterns created by the spirograph on the right side of the image below) that creates different patterns depending on the gear ratio between the gear and the outer gear tracks as well as the distance from the center of the gear upon which the user places the pen. The gears range from 29 to 43 teeth.
Concept and Ideal Interaction: When I laser-cut gears from acrylic square scraps I was amused to realize that the "scrap" portion of the acrylic with the gear cut out doubled as a spirograph. Thus came the inspiration to create a spirograph as the 2nd prototype, since it nicely complemented the first. Building upon the idea of having the two prototypes complement each other, I purposefully made all of the gears swappable between the two prototypes, so that each gear as the right holes for the harmonograph, but also the right holes for the spirograph. Thus the user can realize by moving gears between prototypes that both drawing apparatuses are based off of the same concept of gear ratios and would find delight in using the exact same gear set for 2 different mechanisms. The spirograph is something that a lot of children have played with when they were young (well, maybe before the advent of computer and video games...) so I wanted to compare and contrast something familiar to us, the Spirograph, with something more novel, the hand-cranked Harmonograph.
Problems and Improvements: Moving forward, I feel that the spirographs alone would definitely not be sufficient for an exhibit. I would either want to have it complement the harmonograph set-up, or somehow enhance the user interaction to invite more discovery and something more surprising, for instance, a 3-gear spirograph.
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