rope&pulley at ITP Spring Show
video: Gian Pablo Villamil
May 13, 2008
May 08, 2008
Upcoming Events
Thesis Presentation
Every graduating student in my program is required to give a twenty minute presentation on their thesis project. My presentation about the rope&pulley performance system I developed will take place on Thursday evening at 9:00pm EST. You can watch my presentation in two ways:
On the Web:
http://itp.nyu.edu/shows/thesis2008/video-stream/
- the presentation is streamed live and also recorded for later viewing
In Person:
721 Broadway
4th Floor - Room 447
New York, NY 10013
ITP Spring Show
My rope&pulley system will also be exhibited in the ITP Spring Show, where I'll demonstrate a different application of the system -- as an instrument for informal musical collaboration
Monday, May 12: 5-9pm
Tuesday, May 13: 5-9pm
This Spring Show is also located at the addressed listed above, but takes up the entire fourth floor.
April 26, 2008
April 25 Drawing
April 25, 2008 [tex|ges]ture Drawing - compressed charcoal, oil pastel on butcher paper (96-inch x 36-inch). While listening to SoundGarden (Boot Camp) and Bjork (Pagan Poetry) and trying to map out my final thesis performance, the drawing disintegrated into another gestural exploration.
April 18, 2008
New Pulley Assemblies
All of the pieces for a single assembly are together. I'm happy with the way the unit looks and feels. I'm a little dissatisfied with the way it turns, though, so I'll need to do a bit more sanding to make sure the wheel spins as freely as possible.
April 15, 2008
Pulley Encoder Boards
Today I etched two test boards for the pulley encoders: the RJ-45 breakout board and the emitter/detector pair board. I wanted to make sure that the board design worked correctly before ordering multiple copies of the boards. After soldering the components onto the boards, I connected a CAT-5 cable between the newly fabricated boards and the interface board I made last week. Before plugging anything in, I checked continuity on the various traces to make sure things were wired properly -- or so I thought. When I plugged in the unit after testing, I found that it didn't detect rotation. I inspected the infrared LED on the detector and found that it wasn't glowing (I used my digital camera to check). I wasn't completely surprised; when I hacked apart the mouse circuit board, I found that the X- and Y-axis LEDs were wired together. To fix this problem, I soldered the second IR LED onto the bottom of my interface board. Still no luck. Double checking things, I found that copper traces were bridged on one of the the circuit board I etched. After fixing the bridged traces, I found that the circuit still didn't work. From prior experience, I figured that either the LEDs, the phototransistors, or both were probably blown, so I decided to try again with another mouse.
April 13, 2008
Pulley Fabrication at Glide Design
This afternoon I returned to Glide Design to have my pulley parts fabricated on a CNC milling machine. David Liatti tweaked my designs to make sure the mill produced the best results. The sounds of machinery running, the smell of sawdust, and the opportunity to spend the afternoon watching and learning from a man who practices the art of converting ideas into physical objects was inspiring. Thank you, David!
April 08, 2008
April 8 Drawing
Yesterday as I was looking for inspiration, I found an Erhu recording from the subway platform last November. I liked that I could use my rope to "bow" the sound as I applied granular synthesis to it. I used this sample yesterday for my first drawing with the Rope&Pulley. Today, I made a larger drawing. One of the ropes controls the location of the sampling "window" (ie, the area of the sample the granular synthesis engine looks at) and the other controls the output volume. This was a fairly crude demo.
April 07, 2008
April 7 Drawing
Oops... or Happy Accident?
So I goofed -- maybe. When I modeled the pulleys earlier this week, I somehow messed up the dimensions. I drew the model too small -- and only caught the mistake after I purchased my materials. Remember measure twice -- cut once? Well, I didn't cut yet, but I definitely didn't measure twice.
I was not thrilled about correcting my mistake, as it will take some time to correct it. Further complicating matters is that obtaining the correct material dimensions will become more difficult, too. I will need to go to Dimension Lumber to get a custom piece milled -- and I prefer not to do that now because of the time involved. I was also somewhat concerned about the aesthetics of the pulleys, but maybe the smaller pulley looks nicer. It's going to be hard to say without seeing it build. The point of these remaining weeks is to develop my performance -- not to sweat mechanical details.
I'm going to sleep on it, consider the feedback I've received from friends, and then decide in the morning.
April 02, 2008
Designing "With" Constraints
Today has been another marathon CAD session.
I created the electronic compartment cover (which is subject to change depending on the final contents). I'm waiting to hear back about milling the parts before I make any more changes. I expect that there will be some finessing to do once I build up another encoder board. Although it is tempting to start pushing towards ready-built solutions like those found at Acroname or switching over to an optical mouse encoder system, it's too late in the game to try new stuff that might not work even if it might ultimately make my life easier. I have a working system now that will serve me until the next phase of this project.
Alibre Design Xpress is powerful and pretty easy to use. One of the coolest features is the way "assemblies" work. One I sketch individual parts, there are tools for "gluing" and aligning the parts together so the form an assembly.
Unfortunately, it is also easy to get lost in the miles and miles of faces and edges. Also, it is a tool that, at least for the present. has "obsession potential" for me. I was like this with Google Sketchup, too, when I was learning it. My tendency is to become obsessed with figuring out how to do something when I run into an obstacle -- and ignore time limits I might place on my work. This is something I must avoid falling into in these final weeks, when the focii are going to be the performance, the presentation, and the paper.
Close to Fabrication
Yesterday, I alternated between programming and 3-D modeling. I've assembled most of the components for the pulley supports. It has taken probably 8 hours in total to build this 3-D model. I ended up recreating the assembly this morning because some of the constraints I created on the previous assembly prevented me from moving the pieces around.
In some ways, this looks pretty similar to the mode I drew in SketchUp almost two months ago; however, this model has 3-D models of actual parts that I will purchase this week and the dimensions are exact.
I still need to create a design for the housing that covers the encoder, but that is a job for this afternoon/evening.
March 31, 2008
New Old Rope
I now have a 60 meters of used rope to build my next units. Special thanks go out to the great folks at the City Climbers Club. Once my final mechanical designs are done this week, I will be building again.
March 06, 2008
Midterm Presentation
Here's video of my midterm presentation.
February 24, 2008
Mounting Systems
I've also been working on mounting systems this week. After the testing I did with Martha Mason and Wendy Richmond last weekend, I've been trying to improve the mounting system and and the pulley supports so that the rope stays on the pulley. Martha pointed out that a dancer needs vertical space to work in as well as horizontal space. By opening the pulleys into a triangular formation, I was able to give her the vertical space she longed for.
I bought some pulleys from the hardware store and tried mounting them to the Super Clamps. Mounting them was easy, but as I discovered today, the pulleys are not right for my system. They introduce far too much friction and acoustic noise. They really take something away from the quality that the system had before.
I also experimented with ways of mounting the pulleys that allow me to adjust them easily. While I liked the way the pulleys look when they're mounted with the pipe running through them, this will be difficult to construct. For now, I think I'm going to stick with the super clamps.
February 23, 2008
Building a Wooden Pulley (continued)
I want to be able to work with two pulleys simultaneously, so I'm adding the rotary encoder to wooden pulley I started building last week. The PS/2 mice have turned out to be quite a clever hack because each one gives me two rotary encoders and three switch inputs in exchange to two pins on the Arduino. I've started thinking a bit more about multiples -- and while this may be a little premature, I want to work out a bit of the technical end of this before getting too heavily into final fabrication.
I've invested rather heavily in this for the past two days. Perhaps because this is more comfortable for me than other things that need to get done now -- like preparing for the mid-term presentation.
What this does mean, however, is that I have the pieces for a much more modular system. I'm envisioning a hub that I can plug each pulley into using a single CAT-5 cable. This makes the performance setup clean -- and won't require any soldering.
February 15, 2008
Iterations: A Wooden Pulley
Today I worked on fabricating another two pulleys out of wood. I finished drilling well-aligned shaft holes in the side pieces and made new pulleys out of particleboard and plywood. The most time-consuming part of this process was cutting the circles out of with the bandsaw. I remembered that there is a jig for cutting circles, but didn't want to spend time figuring out how to construct it in order to cut six circles. I first started by cutting around the contour of the circle, but ended up just making tangent cuts and then sanding away the excess. I was really trying to have another pulley finished by Saturday so I could test two of them with Wendy and Martha, but that doesn't seem to be realistic at this point. I still have to make the encoder structure.
The completed wooden pulleys:
Building Another PS/2 Connector Breakout Board
I constructed another P2/2 Connector Breakout Board so I can attach another pulley to my performance system. This time, I've annotated the photos in Flickr so the next time I construct one of these I don't have to think how to build it again.
The Week in Review / Request for Feedback
It felt very good to spend much of the day in the shop working with my hands. Much of the week, however, was spent struggling with how to make progress on the materials/form of the rope&pulley and also struggling with what I am producing.
Earlier in the week, I was researching materials. There are two directions I am considering: natural wood (mahogany, maple, walnut, cherry, etc) or recycled parts. The natural wood direction comes from my appreciation for naturally finished wooden instruments: electric and acoustic guitars, pianos, etc. The recycled direction relates more closely with one of the themes of the project which is, in a way, the recycling of musical content and the loop-based music metaphor.
When I got stuck researching, I tried to work a bit with the form. I started with raw sketches and then tried to work material in Google Sketchup.
I spent too much time trying to manipulate the materials in Sketchup, though, and became frustrated. A breakthrough occurred when I realized that I could use foam to quickly work through ideas. My previous prototype was cardboard, which is durable, but not easy to work with quickly.
Pretty in Pink: A photo essay about my process today. Click on the individual pictures for notes.
I made three new prototype shapes today and I'm looking for feedback on them.
February 11, 2008
Cutting New Supports
I'm crafting another rope&pulley system -- this time out of wood to address some of the problems I've observed with the cardboard prototype -- and also to explore materials.
1-inch x 3-inch pine stock cut into rough forms to make a new set of pulley supports. I'm going to resize the paper templates I used when I created the cardboard prototype so I can accurately drill and shape these pieces.
February 07, 2008
rope&pulley Tests
Wendy came to ITP today to try out the rope&pulley system. We also shot some videos which better explain the interaction between the user and the system.
Introduction
Here, the rope&pulley is controlling the playback speed, direction, and volume of a sample from Jimi Hendrix's "Red House."
Explanation
Vertical
February 06, 2008
Max Patch Revisions
Today I made some revisions to the Max/MSP patches that interface the rope&pulley to the computer. In preparation for the videotaping session I'm doing with Wendy tomorrow, I wanted to make sure that it was easy to switch back and forth between the different patches. When I've done that in the past, I've always run into trouble -- I invariably forget to configure some part of the patch. While cleaning up the patches I found that I could structure things in a way that may make it easier to combine them should the need arise.
I have three different versions of the patch now:
Audio
- rope&pulley controls playback direction (and optionally speed) of user-selectable .wav audio samples.
MIDI
- rope&pulley plays notes on a MIDI synthesizer and can adjust two user-configurable MIDI realtime controller values.
Movie
- rope&pulley scrubs a looped QuickTime movieplays. Scrubbing rate is mapped to the pulley's rotation speed and the scaling of this value can be adjusted from the patch.
February 04, 2008
Exercise Equipment Investigation and Observation
I visited the Coles Athletic Center at NYU with Lisa Lurie to observe gestures and get a sense of the haptic feedback that exercise machines provide. While Lisa worked out on the rowing and elliptical machines, I recorded my observations by sketching. I also spent some time working out on the machine to perceive the force feedback it delivered.
General Observations
- When you step into the workout room, all you can hear is the sound of whirring equipment
- The row of elliptical machines looked like a massive multi-cylinder engine as the pistons moved in and out.
Rowing Machine
- Lisa pointed out that the trade-off of energy on the rowing machine is pleasing. In the first half of the cycle, you work to pull the handle to your abdomen. To complete the cycle, you allow the handle to return to its starting point and the machine does the work.
- The rowing machine provides a great deal more resistance than my pulley.
- There is a fan in the rowing machine. Interestingly, the fan spins in only one direction. This may be useful for me. It raises the question of whether the rope&pulley needs to have some sort of inertia. I was thinking about whether to add weights to the pulleys, but another way of approaching this is to make the pulleys behave like bicycle wheels: pulling on the rope adds energy to the system, but the rope won't continue to spin. This may be a tricky mechanism to built.
- The rowing machine works out a bunch of muscle groups. A body takes several different shapes while using the machine from very compressed to fully extended.
- The rowing machine is designed ergonomically for the action it is meant to receive. The handle exits the machine at the height you should be pulling it towards on the abdomen.
- The sound of the rowing machine corresponds to the motion... ZZZzzzZZzzZz z z z ZZZzzzZZzzZz z z z
- There is an expressive quality to the gestures the body makes when exercising on a rowing machine.
Elliptical Machine
- We also tried the elliptical machines
- When using an elliptical machine, the torso is stationary. The arms and legs move and the shoulders twist, but the torso remains in practically the same position.
February 01, 2008
Week 2 Presentation: A Visual Reflection
This evening, I presented by visual reflection to the thesis seminar class and gave a short demo of the current system. Despina asked the class to come up with lists of words that resonated with each of our presentation. The following words were associated with my reflection and demo:
theremin
gestural
expressive
skeletal
movement
tactile
mechanical
playful
delight
contrast (between organic construction and electronic sound)
inventive
January 30, 2008
Pedal Prototyping
I built a rough foot pedal assembly for the rope & pulley system. I'm not quite sure what to make of it just yet, but it didn't feel right. Previously, pulling the rope towards my body would trigger a note on the synthesizer. As I pulled with increasing speed, the pulley system would increase the volume of the note along with a sound modulating parameter. As I pulled with decreasing speed, the system would decrease the volume and modulation parameter. Once the pulley stopped rotating, the system would turn off the note on the synthesizer. Today, I changed my code so that the rope only controls volume and modulation. I used the two foot switches I built to trigger two different notes on the synthesizer. It felt a bit more like playing a piano with my feet. I felt like I couldn't move as freely because my feet needed to be on the switches for the notes to stay on.
Ideas:
- Maybe there is an "initial state" of the instrument -- akin to an open string on a guitar or violin. (This can be tuned to the user's preference). This way, stepping off the footswitches still allows sound to occur when the rope is pulled.
- Does it make sense to allow more than one switch to be pressed at a time? I like the idea of being able to play intervals or simple chords with the system, but it doesn't make sense with the string metaphor.
- This is the synthesizer setup -- what about the sample playback setup? What experiments can I do there to push forward a bit?
- How do I capture a "gesture" with the rope like a rapid direction change?
Thesis Project: Rope and Pulley
During the course of this thesis project, I will develop a new electronic musical instrument that combines the expressive possibilities of large-scale human body motions with the sonic flexibility of computer-based synthesis into an intuitive live performance tool. Through frequent user-testing, a review of research in the field of New Instruments for Musical Expression, and specific attention to a disciplined creative process, this thesis will also investigate and comment on the relationships between tools and the work they are used to produce as well as the process a toolmaker goes through to develop an instrument.
I started working on this project as a sketch for Performing Technology last semester. It turned into my final project. You can look at the background information here.
January 18, 2008
User Testing
Yesterday, several people looked at my rope and pulley instrument / interface. Generally speaking, they all liked what they saw and found the interface to be intuitive. I didn't have to really explain what to do with it -- they "got it" almost immediately.
The Test Setup
- rope & pulley system connected via Arduino to computer running Max patch
- computer connected via MIDI interface to Roland M-DC-1 dance module
When my right side faces the computer, pulling the rope towards my body triggers a note on the MIDI synthesizer. Pulling the rope with increasing speed increases the volume of the note as well as a sound modulating parameter. Decreasing the pulley's speed decreases the volume and modulation parameter. When the pulley stops rotating, the system turns off the note on the synthesizer.
I also demonstrated the original performance patch which plays Jimi Hendrix's "Red House" when the rope is pulled.
Observations
- It was difficult for me to come up with questions on the spot to ask other than, "how did it feel?", "was it intuitive?", etc.
- I was hoping to observe something that would bring me an idea for the next direction, but I'm not sure if I saw something.
- I found myself explaining and demonstrating the system to generate interest in the idea even though the system was only playing a single note.
- The system needs a bit more refinement in order to demonstrate it quickly. I sometimes get flustered when I switch between modes because it doesn't work immediately. I either need to write down the steps for setting it up or fix the Max patch so it does a few more of the setup functions automatically.
- When Amit was teaching us about user testing last year, he focused on picking a particular task. What was the task I wanted tested? It was hard to get specific answers because I wasn't asking specific questions.
- The responsiveness of the system is an important feature. Right now it feels good.
- All testers found that synthesizer version of the system really needed something to happen when the string was pulled back in the direction of the sensing wheel. It wasn't clear what that something should be, though. Shinyoung suggested some sort of record scratching sound. Rui understood the technical problem I was having with mapping volume / modulation with a positive and negative motion source. But he agreed that it felt strange that nothing happened in the "negative" direction. For this reason, he found that he liked the interaction with the computer-based sample playback ("Red House") better. The sample playback corresponded directly to the motion he was making with the rope. As he pulled the rope towards his body, the sample played "forward", slowing down and speeding up as he pulled with varying speeds. When he pulled the rope in the opposite direction, the sample responded in kind.
- One of the testers was very much interested in the body motion available as a result of this system. Being a "non-musical person", she was interested in how someone moves when playing the instrument. She wanted to see the installation of this instrument afford a nice set of gestures / body movements for the user. To observe this sort of behavior, I think I may need to build another unit that can easily be mounted horizontally, vertically (or on any angle, for that matter).
- Another tester enjoyed the materials the system was made out of. He felt like he could be rough and expressive with it because it was made out of discarded materials. Because the interface was not "precious," he felt that he could play hard. He mentioned that he wouldn't feel bad breaking the string or some other part of the mechanism because he had the sense that things would be easy to fix. If I can get the knot right, this would probably be the case. The only things I really worry about in the system as it is (made out of cardboard), is a kid trying to hang off of the rope. What I've observed several times is that people playing with an interface for the first time want to play ROUGH as the developer looks on in horror.
- I want the ability to change pitches on the instrument -- but not with the pulley. I want some sort of system on the floor that allows discrete pitch selection. One of the testers agreed with this.
- There may be something important about the fact that you can hide behind this instrument (like a guitar, piano, or even a laptop)
- I am hesitant to provide speed control over the sample playback unless it has some very natural smoothing that doesn't allow it to get too much out of control. These could be done as a series of short user feedback experiments. The other trick in allowing speed control is that stopping the rope must instantly stop the sound. This is one of the affordances of the current system. This could change if I add more mass to the pulley, however. A metal pulley will definitely want to keep spinning unless the rope is heavy enough (and has enough friction) to stop it.
- It was suggested that I ask other people (non sound people) should try it out and see if they get the mapping
- Jamie suggested trying a collaboration with motion theater people (like Judson Church) to establish a type of choreography.
December 01, 2007
Shaft (can you dig it?)
Today I converted my pulleys to work with the new detection strategy. Instead of using the outer rim of the pulley to rotate the mouse ball, I'm going to attach the optical encoder wheel to the end of the pulley's shaft. To avoid building the pulleys again, I've decided to patch up the hole where the bearings were seated.
