Prompts¶

The main objective is to create a machine which uses movement to reveal the relationships between a hidden algorithm, a visible mechanism, and external objects.

Some possible interpretations of this include:

1. Create motions that activate the dynamics of an object.
2. Create an interplay between algorithm and mechanism.
3. Create a movement which inhabits a body.
4. Create a movement which reveals intent.

Other questions to provoke your thinking:

1. Does it dance?
2. What movements might evoke a familiar somatic experience?
3. Is there a tactile component to the performance?
4. What is the audible experience?
5. Does the physical effect extend beyond the confines of the device?

Examples¶

1. Abstract suspended fabric: three actuated tendons moving a piece of gauze in air.
2. Tabletop juggler: three actuated ‘fingers’ catching, batting, and flinging pinballs back and forth across a gently tilted surface.
3. A musical device directing a cascade of ball bearings.

Learning Objectives¶

1. Explore machine choreography as an art form.
2. Demonstrate basic use of a stepper motor.
3. Develop an actuated mechanical structure capable of live performance.
4. Develop a movement concept into mechanism and algorithm.

Deliverables¶

Each group will be responsible for developing a simple shared performance machine. This can use the basic actuator assembly as-is or redevelop it as necessary. Most performances will require the addition of props or other structures.

Each individual will be responsible for developing and documenting a performance scene using the machine. No specific duration is required: a successful performance could be as short as a single gesture, or as long as eternity. Each individual will provide:

1. Short video (less than one minute) posted to the blog.
2. Live demo in class.

Technical Approaches¶

Mechanical resources include:

1. three stepper motors (NEMA17)
2. stepper motor driver: A4988 shield on Arduino, 12V power supply
3. laser-cut plywood motor mounting
4. motor tendon drive arms
5. hard-wire pushrods
6. tendons
7. fabric
8. rotational joint bearings (shoulder screw, bushing)
9. lazy-susan bearings
10. timing belts and pulleys
11. springs

Some options for the software implementation include:

1. Custom Arduino sketch.
2. Laptop-side scripting with communication to embedded sketch. Host options include Python, Max/MSP, Processing, etc.
3. Fixed G-code sequence with grbl package.

Rules and Limitations¶

1. No physical changeover between separate performances. I.e., the machine must be fully shared, no changing props or reconnecting pieces.
2. The software scene change should be limited to reflashing the Arduino; ideally, it would be executed by changing a parameter or choosing different scripts.
3. Please limit construction to laser-cut plywood and available parts. If you feel you need additional mechanical components or different fabrication resources, please talk to the instructor for clearance or possible purchase.
4. Additional uncontrolled energy sources (e.g. a fan, lamp) are allowable.
5. No anthromorphic puppets.
6. No drawing machines.
7. No additional controlled actuation beyond the three provided stepper motors.
8. No exposed water or liquid.
9. No sensors.
10. No network data communication.
11. Music may be included only if composed and performed wby the student. Diegetic sound is greatly preferred, i.e., sound created directly by the machine itself.

Evaluation¶

1. Is the result surprisingly animate?
2. Is the underlying dynamic physical process apparent?
3. Does the performance behavior balance algorithmic and mechanical processes?
4. Are the boundaries between algorithm and mechanism legible?

Discussion¶

The emphasis of this exercise is on dynamics and motion. Please refrain from story-telling narratives. Instead, think like a dancer who conveys an idea purely through motion and pose.

Interactivity is still possible within the limitations, but will be limited to direct mechanical response.