Working With Lasers! (M2 Lasered!)

For this Comp Fab assignment, I had to design three different designs using code that utilize the three main methods of laser cutting; Laser engraving/etching, vector line marks and the standard laser cut. Etching moves the laser across a designated area at fast speeds to leave a burned mark, but not much depth. laser vector lines leave an indent, but do not cut all the way through. A laser cut separates the material fully.

import Turtle.*;
Turtle t;
import processing.pdf.*;
import processing.svg.*;
String fileName;

//global variables
color cut = color(255,0,0);//use stroke(X); to change the color of the lines
color etch = color(0,0,0);
color line = color(0,0,255);

void setup() {
  size(500,500);
  background(255);
  stroke(0);
  fill(etch);
  t = new Turtle(this);
  noLoop();//only use draw once
}

//saving the drawing
void keyPressed() 
{
  //press the 's' key to save a pdf of your drawing
  if (key == 's') 
  {
    //name of file is "turtleDrawing" plus a unique(ish) number
    fileName= "turtleDrawing"+ second() +".svg";
    beginRecord(SVG, fileName);
    draw();
    endRecord();
  }
} 

Design 1: Hex Pattern

For this pattern, I wanted a pattern of randomly changing hexagonal holes; some empty, some full. Like a beehive populated by some bees. The system creates a hexagon at a set interval where on even layers, the even layer hexagons are offset by the radius.

void draw () {
  stroke(line);
  hex_grid(30.0,75.0,6,5,40,20);
}

void hex_grid(float x, float y, int rows, int columns, int size, int spacing)
{
  for(int i = 0; i < rows; i++)
  {
     for(int j = 0; j < columns; j++)
     {
       //color selection
       int rand = (int)random(0,2);
       switch(rand)
       {
         case 0://will laser cut a hex hole
           stroke(line);
           break;
         case 1://will just be a weak cut
           stroke(cut);
           break;
       }
       
       //drawing code
        float _x = j * (size * 1.7 + spacing) + x;
        float _y = i * (size * 1.5 + spacing) + y;
        if(i % 2 == 1)//if odd row...
        {
          _x += (1.65 * size) / 2 + (spacing * .5);
        }
        turtle_walk(_x, _y, size, 6); 
     }
  }
}

Design 2: Demo Cube

This design was made to demonstrate the three methods of using the laser. each “face” of the cube was done with a different method. As can be seen, the raster etch was very shallow. I later found out this was because the laser power setting had been tampered with. The rhombuses are also not correctly aligned. I couldn’t use the rotate function in processing because of the noLoop in the setup.

void draw () {
  float x = 100.0;
  float y = 100.0;
  float offset_x = 28;
  float offset_y = 50;
  float size_x = 50;
  float size_y = 30;
  
  //cut part
  stroke(cut);
  noFill();
  rhombus(x,y,size_x,size_y,0);
  
  //vector line part
  stroke(line);
  noFill();
  rhombus(x+offset_x,y+offset_y,size_x,size_y,2*PI/3);
  
  //etch
  stroke(etch);
  fill(etch);
  rhombus(x-offset_x,y+offset_y,size_x,size_y,PI/3);
  
  //outline cut
  stroke(cut);
  noFill();
  t.setX(x);
  t.setY(y-size_y - 7.5);
  t.setHeading(60.0);
  for(int i = 0; i < 6; i++)
  {
    
    t.right(60.0);
    t.forward(70.0);
  }
}

void rhombus(float x, float y, float size_x, float size_y, float rad)
{
  //println("new rhombus");
  float xs[] = {0,0,0,0};
  float ys[] = {0,0,0,0};
  for(int i = 0; i < 4; i++)
  {
    float selector = 1;
    float _x = x;
    float _y = y;
    if((i/2) % 2== 0)//if second half
      selector = -1 * selector;
    
    if(i % 2 == 0)//top points
    {
      _y += size_y * selector * sin(rad+PI/2);
      _x += size_y * selector * cos(rad+PI/2);
    }
    else//x points
    {
      _x += size_x * selector * cos(rad);
      _y += size_x * selector * sin(rad);
    }
    
    xs[i] = _x;
    ys[i] = _y;
    println(_x, " " ,_y);
  }
  //println(xs);
  //println(ys);
  quad(xs[0], ys[0], xs[1], ys[1], xs[2], ys[2], xs[3], ys[3]);
}

Design 3: Gears

I wanted to make a gear system that was modular with both size and teeth count. The system utilizes arcs and creating a lines between the two radai of the gear.

void draw () {
  noFill();
  stroke(line);
  circle(250,250,310);
  circle(250,250,255);
  gear(250.0,250.0, 272.5,20,20);
  
  stroke(cut);
  gear(250.0,250.0, 350.0,25,25);
  gear(250,250,180,15,40);
}

void gear(float x, float y, float diameter, float teeth_num, float teeth_length)
{
  float angle = 2*PI / (2 * teeth_num);
  for(float i = 0.0; i < (2*PI); i+= angle*2)
  {
    float ang1 = i;
    float ang2 = i + angle;
    float ang3 = ang2+ angle;
    //teeth bump
    arc(x,y,diameter+teeth_length,diameter+teeth_length,ang1, ang2);
    line(x+(diameter+teeth_length)*cos(ang1)/2, y+(diameter+teeth_length)*sin(ang1)/2,x+(diameter)*cos(ang1)/2, y+(diameter)*sin(ang1)/2);
    
    //teeth groove
    arc(x,y,diameter,diameter,ang2, ang2+angle);
    line(x+(diameter+teeth_length)*cos(ang2)/2, y+(diameter+teeth_length)*sin(ang2)/2,x+(diameter)*cos(ang2)/2, y+(diameter)*sin(ang2)/2);
  }
}

Conclusion

Lasers are an amazing technology that can create amazing 2D geometries. The main restriction with using a laser is both the Kerf and that lasers operate on a 2D plane. To create more interesting geometries with a laser in the future, multiple cuts will have to be used and the end products will have to be stacked to form a 3 dimensional object.