Home Chapter 12 DC gearhead motor, darlington transistor, and PWM with a passive infrared sensor
DC gearhead motor, darlington transistor, and PWM with a passive infrared sensor

"I generally think of motors, lamps, circuits, etc, as they are used in my sculptures as having little interest in themselves; it is the way they are integrated into a functioning system that strikes me as the essential application of contemporary technology.”
~James Seawright

 

Question: How can I add motion to my projects?

DC motors and sensor feedback loops are the muscles and brains of industry, and they provide artists and inventors with a variety of unique and sometimes counter-intuitive applications for motors.

Molholy Nagy (1895--1946) created the film "Light Display Machine: Black, White, Grey" (1932) to integrate film media and create a play of light in space. He used a rotating kaleidoscope that could project patterns of light, color, and shadow. Nagy was so excited about the work that he said “The mobile was so startling in its coordinated motions and space articulations of light and shadow sequences that I almost believed in magic." 1 Jean Tinguely (1925--1991), working with Billy Kluver, created Homage to NY (1960), a machine designed to commit mechanical suicide at MOMA, New York. Fragments of scrap metal, motors, paint bombs, bottles of chemical stink, bicycle wheels, and a piano were part of the sculpture’s self-destructive performance.

The contemporary artists Jeff Carter and Susan Giles have been collaborating for years on electronic and interactive works. In this work the artists captured video footage of

 

Footage by Jeff Carter and Susan Giles. 2000.  Vedanta Gallery, Chicago.

 

people walking in Indonesia and reanimated that act of walking by spinning the video monitor at about the same speed that the pedestrians walked. This work utilized a powerful motor and a Darlington transistor, such as you will be using in this lesson. The monitor’s orbit and the focus on the feet make the simple act of walking seem both mundane and fascinating. [2]

The contemporary media artist Fernando Orellana has constructed drawing machines that are simultaneously chaotic and constrained in their motions.

 

Drawing machine V.2 by Fernando Orellana, 1999.

 

Drawing Machine 3.14159 (2001) explores the possibility of giving machines the ability to create artwork without human interference or input. The artist has expressed his desire that the work produced is equal in quality and complexity to human-made artwork. A BS2 drives a DC motor and counterbalanced pens, which make intermittent contact with the paper. The drawing paths and pressure are the result of the kinematics of the mobile that holds the pen. However, the inputs from viewers’ voices that activate the motors allow a complex and random drawing that could never be repeated twice. [3] The code and schematic for Fernando’s work are at the end of this chapter.

 

The Unstoppable Hum by Sabrina Raaf. 1999.

 

Sabrina Raaf created The Unstoppable Hum (2002), an installation work that acknowledges the ceaseless hum and random noise found in the human body. The building the sculpture inhabits provides a metaphor for the body.

With this installation, Raaf has connected a whole series of sensors and numerous microprocessors to monitor, amplify, and reflect the building’s vibrations and ceaseless hum.

All buildings are like living systems, and as the artist says, “A sometimes subtle, sometimes deafening, but ever present hum extends from our walls, our refrigerators, our computers, and our whole electronically infused late 20th century living/working environment. There is secondary set of hums, which we experience when we place our hands over our ears. This is the hum of our own blood rushing, the strange high frequency in our ears, and the vibrations of our voice boxes.” [Artists web site] In this work, contact microphones and microprocessors “listen to” elements such as telephones, vibrating ventilation pipes, human footsteps, and automatic doors. This outputs to fans blowing into the necks of individual glass bottles, which emit sensually dissonant musical tones and phrases. Micro video cameras also monitor and play back images of inhabitants of the space, which are distorted by a thin flesh-like membrane that stretches over the LCD screen, which plays back the images. Raaf used power-driving transistors to activate the motors in this work similar to the ones you will be learning to use in this chapter. [4]

The contemporary Artist Jane Prophet uses motor controllers and devices called linear actuators to activate a milled aluminum sculpture in Birminham UK.

 

 
 Jane Prophet, (Trans)Plant 2008

(Trans)Plant (2008) is a mechanical and kinetic art work at a very large scale. This self-assembling sculpture is inspired by the structure of cow parsley (Anthriscus sylvestris) a native British plant. The artist writes "In the past children used it's hollow, furrowed stems as peashooters." and this plant is quite common in the UK.

Increasing the scale of this everyday plant gives it an unexpected emphasis and it becomes surprisingly grandiose. The jointed sculpture is made from milled aluminum blocks and tubes. The work is activated throughout the day as the branching structures rise from a collapsed state, they snap into the organic form you see in the photo above.  

(Trans)Plant changes and morphs as it assembles itself, into a three dimensional form. At the touch of a button the installation moves and its branches collapse and droop, until it is activated again.