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No-tech Puppeteering |
The task at hand was to make 3 human-actuated human sketches to create motion for visual and haptic feedback. With the aesthetics being of little relevance and building Rube Goldberg machines simple enough, perhaps the biggest hurdle to overcome in the design process was keeping things different- using different forms of energy, movements and materials.
I didn't want to design something and then realize that I don't have the stuff to build it. So, the first thing I needed to accomplish the task of making things move was, well- things! Since I don't seem to have accumulated stuff I don't need (yet!), I went to the next best option: SRL. However, I quickly learnt that there is no dearth of stuff I could use, and so I moved on to the designing and building.
The movement I set out to create for the 1mm sketch was bobbing. The first most apparent sketch for this was to make a cantilever type setup. I accomplished this quite quickly with a popsicle stick held in place with a bench vise. I also added in a piece of wood (with a cat head drawn on it) and secured it in place with some wire to emphasize where one could experience the said prodding or nudging.
But since this was just too easy and not quite in the spirit of the assignment, I proceeded to make a second sketch which was inspired by a mechanical toy.
To build this I used some wooden dowels, a part that seemed like a motor mount, wire, and one piece of wood to served as a mounting, and another cylindrical piece which (very conveniently!) had a slightly off-centred hole.
After securing it all in place with a screw, wire and tape for good measure I was almost there. I had initially intended to make a stand with carton boxes but decided to use the metal step stool we have at the lab instead. This meant an uglier setup but significantly less effort and perhaps a stabler final result.
To complete the setup, I fastened a pipe at the top to keep the bobbing dowel in position. Also, I added a wooden ramp to allow for activating the mechanism by sliding a weight down rather than manually rotating it.
Given how convoluted and haphazardly put together this was though, I wasn't quite so surprised when it didn't work on the first try.
The primary issue was the rotating cylindrical wood piece jamming at the corner, and I managed to resolve it by adding a nut to keep the piece from moving entirely to the side.
And finally I had a functional bobbing toy, that was complicated in a true Rube Goldberg fashion.
Using methods like vibration due to deformation (or even a spring) results in movements that damp over time unlike the rolling mechanism in the second sketch. But given how small and simple the motion is the resulting difference is quite unnoticeable for most of the time period, the implementation method made a great deal of difference in terms of the overall effort even though it resulted in an approximately identical final result.
The haptic effect I selected for this case was a texture change. My sketch involved the use of an elastic band and magnets as the main elements.
To build the setup, I repurposed the dowel sticks and mounting wood piece from the 1mm sketch, washers, magnets, an elastic band, push pins and a piece of honeycomb cushioning wrap.
The activation of the setup involved pulling down on the washer which was attached to the top of the dowel. When pulled down sufficiently, the magnet attached to the washer attracted the magnet attached to the honeycomb wrap. On releasing the washer the elastic band relaxed pulling the wrapping paper along with it, resulting in a texture change.
I did not face any notable issues when building this setup. If anything, the only tweaking involved was adjusting the length of the elastic band and paper to get the desired effect.
I initially struggled a bit finding things that changed texture when moved (or stretched in this case), but, in hindsight, I probably could have tried out texture changes cause by wetting surfaces. This sketch was admitedly simpler than the 1mm Rube Goldberg setup, however, in this case, I liked that the haptic feedback changed and was observable before and after the activation rather than just during.
With the scale of motion required quite drastically increased for this sketch, I decided to use a spring for this sketch along with some other readily available materials.
I quickly realized that unlike the previous sketches my challenge here was not to achieve sufficient movement but rather to restrict it.
While one option of limiting motion to the required scale was to activate the mechanism with lesser force, I opted to instead block the movement by using a cylindrical outer cylinder and a cap. I secured everything in place with a glue gun and some tape.
Since this was my final sketch, I also added in a little bit of aesthetics.
The problems I faced for this setup were completely different in comparison to the previous sketches. If I had instead pulled a spring and released it as I had with the elastic band in the 10mm setup, I wouldn't have encountered the issues of uncontrolled motion at all.
In retrospect, despite my initial intention to keep things as different as possible, which I followed to the extent of using different sources of energy for each sketch, my sketches only managed to cover material properties like magnetism and elasticity for most part. Even with just this, the design space was quite wide and I wonder how much more vast it would be had I used heat, fluids and air.
Even so, with each of the scales of movements I feel like I learnt a different set of things. While I'll perhaps never have to build toys or make Rube Goldberg machines for a living, I'm hoping these reflections will still be useful in some way.