$fn = 128;

/////////////////////////////////////////////////////////////////
// Parameters for the model in mm
/////////////////////////////////////////////////////////////////
heads            = 6;   // no. of heads
handle           = 0;   // length of handle
width            = 3.0; // width of comb for 3D printing
thickness        = 5.5; // thikness of comb-back

spacer_height    = 2.10; // hight of the spacer
spacer_peak      = 0.07; // hight of the peak to overcome
spacer_distance  = 1.40; // spacing between spacers (MIN. ==  spacer_peak * 2 + 0.3 !!!)
spacer_length    = 2.60; // length of resting-area for head


/////////////////////////////////////////////////////////////////
// Calculations for the model
// Don't change them
/////////////////////////////////////////////////////////////////
spacers = ceil(heads / 2);
height  = handle + (spacer_height + spacer_distance) * spacers + 0.5;


/////////////////////////////////////////////////////////////////
// Fixed Parameters
// Don't change them
/////////////////////////////////////////////////////////////////
phase = 1.2;


/////////////////////////////////////////////////////////////////
// Spacer model 2D for CNC
/////////////////////////////////////////////////////////////////
module Spacer2D(){
    square([spacer_length - 0.1, spacer_height]);
    
    hull(){
        translate([spacer_length - 0.1, 0]) 
          square([0.1, spacer_height]); 
        
        translate([spacer_length + 0.6, -spacer_peak]) 
          square([0.1, spacer_height + spacer_peak * 2]);
        
        translate([spacer_length + 2.4, (spacer_height) / 2 - 0.1]) 
          square([0.1, 0.2]);
    }
}


/////////////////////////////////////////////////////////////////
// Comb model 2D for CNC
/////////////////////////////////////////////////////////////////
module Comb2D(){
    difference(){
        translate([-thickness, 0]) square([thickness, height]);
        
        lb = sqrt(phase * phase / 2);// - phase/2 * phase/2);
        #translate([-thickness - phase/2, 0]) rotate([0, 0, -45]) square([lb, lb]);
        translate([-thickness - phase/2, height]) rotate([0, 0, -45]) square([lb, lb]);
        translate([-phase/2, height]) rotate([0, 0, -45]) square([lb, lb]);
    }

    // Add spacers in position 
    for(i = [0 : 1 : spacers - 1]){
        z_pos = i * (spacer_height + spacer_distance) + 0.5;
        translate([0, z_pos]) 
          Spacer2D();
    }
}


/////////////////////////////////////////////////////////////////
// Comb model 3D for printing
/////////////////////////////////////////////////////////////////
module Comb3D(){
    linear_extrude(width) Comb2D();
}


/////////////////////////////////////////////////////////////////
// Display model
/////////////////////////////////////////////////////////////////
Comb2D();
//Comb3D();