Archives for the month of: March, 2013

First step complete- a solid base.

photo-5

 

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I’ll be building something along the lines of the second sketch.  Basically, a small piece of plastic (diffraction grating) moves in x-y via joystick- between two crossed polarizers, creating a transparent window to a scene behind it (see sketch 2).  The movement of the window is done by a pulley system inspired in part by printers- the servos are mobile, moving along tracks.  Polarizers are glued between glass, everything is taking place between the glass :
photo-2I collect scrap plate glass- the cleanest stuff I have are these 2’x1′ pieces.  I’d should probably cut them down, but thanks to american science and surplus I can at least afford a lot of polarizing material.  We’ll see how this goes…
photo-3

Robokitty created by me, Cody, Marissa &  Kayleigh. (Real kitty in the background is mine :)).

The arduino controls 2 servos and some LEDs. The original design had a 3rd servo which would rotate the head, however this proved hard to implement.
Code:
//////////////////////////////////////////////////////////////
#include <Servo.h>

const int ledPin = 11;
int eyebrightness = 0;

Servo paws;
int pawsValu = 50; //initial servo angle
int dir = 1;

Servo tail;
int tailValu = 50;
int dir2 = 1;
///////////////////////////////////////////////////////
void setup() {
//Serial.begin(9600);
pinMode(ledPin, OUTPUT);

paws.attach(5);
tail.attach(3);

}
//////////////////////////////////////////////////////
void loop() {

//control speed of paws/tail by adjusting ‘dir’ value and delay value

pawsValu = pawsValu + dir;
tailValu = tailValu + dir2;

if(pawsValu >= 100) {
dir = -5;
} else if(pawsValu <= 80){
dir = 5;}

paws.write(pawsValu);
if(tailValu >= 120) {
dir2 = -1;
}else if(tailValu <=30){
dir2 = 1;}

tail.write(tailValu);

eyebrightness = map(pawsValu, 65, 100, 0, 255); //eye brightness follows paws, somewhat
analogWrite(ledPin, eyebrightness);

delay(50);
//Serial.println(eyebrightness);
}

This one is my favorite- a shark jaw forms a doorway to a sort of cavern, within which a dancer-like form cycles between two poses, while the entrance to the cavern fades in a cycle between transparent/opaque/transparent/ (using polarizers, perhaps).  The two cycles go in and out of phase with one another, while some lone teeth mounted on magnets spin erratically just outside the entrance.

(click to view full size) IMG_4215
IMG_4211

Sketch 4a uses polarizers cut into strips to make black censor bars. Push a button, and one will rotate slightly, becoming transparent- exposing some obscene body part (but only for a split second- never enough time to ‘satisfy’ the gaze.  There are restraints imposed on how often the button can be pushed, as well).
The 2nd drawing is just for fun- various frivolous objects- clothing-like (or not)- make their way in front of a risqué photo, timed in a way so as never to reveal everything.
IMG_4233

Polarizers again- as windows into a creepy house.
IMG_4225

Here a small piece of plastic is layered between two polarizers crossed to extinction (i.e. no transmitted light).  The plastic scatters the light- disrupting the polarization to create a little transparent window.  In the sculpture this window is mobile in x-y and exposes small parts of an image/scene behind it.
IMG_4221

Below- an example of what I’m getting at:  two polarizing sheets, one with a photo transparency taped to the back:
IMG_4198
rotate…
IMG_4200
Still the same setup as above, but a piece of plastic (a diffraction grating, for colorful effect) is sandwiched between the two polarizer sheets, creating a ‘window’:
IMG_4209

The next five posts are rough ideas for mechanical sculpture for our midterm.

Sketch 1:   The device below simply illuminates things- it uses a violet laser pointer (similar wavelength to a blacklight) to scan across a square area.  The first drawing is a top down view of the setup.  After the laser hits a curved mirror it becomes a horizontal line, eliminating the need to scan in x.
IMG_4197
Here are results of a quick mock up- I put some paper colored with fluorescent paint behind frosted glass- on the glass you can see the line created by the curved mirror (or a warped piece of silvery plastic, in my case).
IMG_4185I’m hoping my servos are fast enough to be used as a galvo to rapidly scan the light across an area:
linescanIn case that the violet laser doesn’t work out, I’ve been accumulating these “380µm” LEDs from the science surplus store:
led