gears.scad

include <openfusion.scad>

// Personal Constants
in_to_mm = 25.4;
tol = .2;

/* Bore              */ bore = 45 + tol; // mm
/* Height            */ h = 5; // mm
/* Number of teeth   */ N = 32;
/* Diametrical pitch */ P = 12;
/* Pressure angle    */ pa = 14.5;

/* ********************* 
   Calculated Values (distances) 
   *********************/
/* Whole depth                */ ht = (in_to_mm) * (2.157 / P); // in_to_mm * ((2.2 / P) + 0.002);
/* Addendum                   */ a = (1 / P) * in_to_mm;
/* Dedendum                   */ b = ht - a;
/* Pitch Circle (diameter)    */ D = (N / P) * in_to_mm;
/* Base Circle (diameter)     */ Db = D * cos(pa);
/* Root Circle (diameter)     */ Dr = D - (2 * b);

echo("Final size ~");
echo(D + a);

/* ********************* 
   Calculated Values (other) 
   *********************/
/* Circular pitch    */ p = (3.1416 / P) * in_to_mm;
/* Tooth thickness   */ t = (1.5708 / P) * in_to_mm;
/* Clearance         */ c = ht - 2 * a;

module base_circle() {
    // NOTE:
    // The additional .2 is for tolerances
    // and might need to be changed
    circle(d=Dr + tol, $fn=100);
}

module tooth_mesh() {
    x = cos(90-pa) * a;
    xop = cos(90+pa) * a;
    polygon(
         points=[
            [-t,0],
            [-t + x, a],
            [xop, a],
            [0,0]
        ] 
    );
}

module tooth() {
    rotate(90)
    translate([-t/2,Dr/2,0])
    union() {
        square([t,b]);
        translate([t,b]) tooth_mesh();
    }
}

module teeth() {
    circular_mirror(d=0, steps=N)
    tooth();    
}

module gear() {
    teeth();
    base_circle();
}


module final() {
    difference() {
        gear();
        circle(d=bore, $fn=100);
    }
    //circle(d=D, $fn=100);
}

linear_extrude(height=h)
final();

openfusion.scad

/**
	Maths
**/
function rad(degree) = (degree / 180) * 3.14;
function deg(rad) = (rad * 180) / 3.14;

/**
	Modules
**/
module circular_mirror(x=0, y=0, d, steps) {
    aps = 360 / steps;
    for (step=[0:steps]) {
        current_angle = step * aps;
        unit_x = cos(current_angle);
        unit_y = sin(current_angle);
        translate([x, y, 0]) {
            translate([unit_x * d, unit_y * d, 0]) {
                rotate(current_angle) children();
            }    
        }
    }
}

// This is a hexagon, but radius is the distance 
// from the center point to the middle of a side. 
// (rather than to a pointy end) which mimics fusion.
module hexagon(r) {
	rotate(90) circle($fn=6, r=r * 1.125);
}

// Mirror in 4 directions
module quadruple_mirror() {
    children();
    mirror([-1, 0, 0]) children();
    mirror([0, -1, 0]) children();
    mirror([-1, 0, 0]) mirror([0, -1, 0]) children();
}

// Splat children elements equidistance "count" times along 
// a particular vector (x, y, and/or z) over some distance (d)
module splat(d, count, x=false, y=false, z=false) {
    step_distance=d / (count - 1);
    for (step=[0:count - 1]) {
        move = step * step_distance;        
        translate([x ? move : 0, y ? move : 0, z ? move : 0])
        children();
    }
}