key_lower_skull.scad

// Row 4 decorated Cherry MX key

// dimensions Cherry MX connector
c_corr = .2;                // tolerance
c_horiz = 1.1;              // horizontal bar width
c_vert = 1.0;               // vertical bar width
c_dia = 4;                  // cross width
c_depth = 6;                // connector depth
c_space = 4;                // height of hollow inside
c_inset = .75;              // distance connector start to keycap base

//cut out size
cut_h=9;
cut_x=1.4;
cut_y=1;

// decoration
obj = "skull.stl";          // decoration object
obj_pos = [0,-4,10];        // decoration offset
obj_scale = [1.18,1.1,1.1]; // decoration scale
obj_rot = [40,0,0];          // decoration rotation

// keycap shape
head_tilt = 3;              // rotation of top around x-axis
head_pos = 2.25;            // keycap top y-offset
head_height = 11;           // z-offset of keycap top from the bottom of the keycap
cutoff = 6.5;               // cut keycap here to make room for decoration
                            // must be bigger than c_space + c_corr
key_scale = [1.01,1.01,1.01]; // overall scale

// stuff
$fn = 64;

// create basic key shape from dxf frames for base and top
module shape()
{
    hull()
    {
        translate([0,0,-c_inset]) linear_extrude(height=.01) import("base.dxf");
        rotate([head_tilt,0,0]) translate([0,6.75+head_pos,head_height-c_inset]) linear_extrude(height=.01) import("top.dxf");
    }
}

// construct the connector pin
module connector() 
{
    translate([0,0,c_depth/2-.1]) union()
    {
        cube([c_vert+c_corr,c_dia+c_corr,c_depth+.1], center=true );
        cube([c_dia+c_corr,c_horiz+c_corr,c_depth+.1], center=true );
    }
}

//the cut out for eyes
module ovalTube(height, rx, ry, wall, center = false) {
  difference() {
    scale([1, ry/rx, 1]) cylinder(h=height, r=rx, center=center);
    scale([(rx-wall)/rx, (ry-wall)/rx, 1]) cylinder(h=height, r=rx, center=center);
  }
}

//oval tube cutout
module cutout()
{
	ovalTube( height=cut_h, rx=cut_x, ry=cut_y, wall=1.4 );
}


// create the hollow key with decoration
module key()
{
    difference()
    {
        // combine basic key shape with decoration
        union()
        {
            translate(obj_pos) rotate(obj_rot) scale(obj_scale) import(obj);
            
            difference()
            {
                shape();
                rotate([head_tilt,0,0]) translate([0,0,5+cutoff-c_inset]) cube([100,100,10], center=true);
            }
        }

        // subtract scaled basic shape, cut at minimum required height
        difference()
        {
            scale([.9,.9,.9]) translate([0,0,-1]) shape();
            translate([0,0,5+c_space+c_corr]) cube([100,100,10], center=true);
        }
    }
}

// combine key, pin and connector. cleanup below the key
scale(key_scale) difference()
{
    union() 
    { 
        key();
        cylinder( h=c_space+c_corr, r=(c_dia+c_corr)/2 );
    }
    
	connector();

	difference(){
	//	cutout();
		translate([3.1,-3.7,0]) cutout();
	}
	difference(){
	translate([-3.1,-3.7,0]) cutout();
	}
	translate([0,0,-50-c_inset]) cube([100,100,100], center=true);
}