//Design: Parametric shredder.
//Date: 2014-10-20
//Version: 0.2
//Author: M. <domenzain@pmclab.fr>

$fa=0.01;
teeth=5;
outer_diameter=55;
inner_diameter=40;
attack_angle=15;
inner_angle=360/teeth;

module axis_shape() {square([15,15],center=true);}

//Main cutting disk
outer_radius=outer_diameter/2;
inner_radius=inner_diameter/2;
difference(){
    circle(r=outer_radius);
    union()
    {
    for (i=[1:teeth])
    {
        rotate([0,0,360*i/teeth])
        polygon([
                [inner_radius,0],
                2*outer_radius*[cos(attack_angle),-sin(attack_angle)],
                2*outer_radius*[cos(inner_angle),-sin(inner_angle)]]);
    }
    axis_shape();
    }
}

//Washer
translate([2*outer_radius,0,0])
difference()
{
    circle(r=inner_radius,center=true);
    axis_shape();
}

//Outside closure
translate([outer_radius, outer_diameter,0])
difference(){
    polygon([
    inner_radius*[cos(45),sin(45)],
    sqrt(2)*outer_radius*[cos(45),sin(45)],
    sqrt(2)*outer_radius*[cos(-45),sin(-45)],
    inner_radius*[cos(-45),sin(-45)]
    ]);
    circle(r=inner_radius);
}