test-rack.scad

use <MCAD/gears/rack_and_pinion.scad>
include <MCAD/units/metric.scad>

$fs = 0.4;
$fa = 1;

N = 10;
cp = 5;
pitch_perimeter = cp * N;
pitch_radius = pitch_perimeter / 2 / PI;
addendum = 1.0 * cp / PI;
dedendum = 1.1 * cp / PI;

function get_fragments_from_r (r) = (
    (r < 0.00000095367431640625) ? 3 :
    ceil (max (min (360 / $fa, r * 2 * PI / $fs), 5))
);

rack_length = cp;

module our_rack ()
rack (cp = cp, N = 2, width = 10 + epsilon * 4, thickness = 10);

linear_extrude (height = 10)
difference () {
    circle (r = pitch_radius + addendum);

    union ()
    for (t = [0:1/get_fragments_from_r (pitch_radius):1.01]) {
        rotate (t * 360, Z)
        translate ([
                -rack_length / 2 + (pitch_perimeter * t) % rack_length,
                5 + dedendum + pitch_radius
            ])
        projection ()
        our_rack ();
    }
}