NopSCADlib/vitamins/insert.scad

//
// NopSCADlib Copyright Chris Palmer 2018
// nop.head@gmail.com
// hydraraptor.blogspot.com
//
// This file is part of NopSCADlib.
//
// NopSCADlib is free software: you can redistribute it and/or modify it under the terms of the
// GNU General Public License as published by the Free Software Foundation, either version 3 of
// the License, or (at your option) any later version.
//
// NopSCADlib is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
// without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
// See the GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License along with NopSCADlib.
// If not, see <https://www.gnu.org/licenses/>.
//

//
//! Heatfit threaded inserts. Can be pushed into thermoplastics using a soldering iron with a conical bit set to 200&deg;C.
//
include <../utils/core/core.scad>
use <../utils/quadrant.scad>
use <../utils/thread.scad>

function insert_length(type)         = type[1];     //! Length
function insert_outer_d(type)        = type[2];     //! Outer diameter at the top
function insert_hole_radius(type)    = type[3] / 2; //! Radius of the required hole in the plastic
function insert_screw_diameter(type) = type[4];     //! Screw size
function insert_barrel_d(type)       = type[5];     //! Diameter of the main barrel
function insert_ring1_h(type)        = type[6];     //! Height of the top and middle rings
function insert_ring2_d(type)        = type[7];     //! Diameter of the middle ring
function insert_ring3_d(type)        = type[8];     //! Diameter of the bottom ring

function insert_hole_length(type) = round_to_layer(insert_length(type));

function insert_nose_length(type, d) = let( //! The length before the second ring.
        length = insert_length(type),
        ring1_h = insert_ring1_h(type),
        chamfer1 = (insert_ring2_d(type) - insert_barrel_d(type)) / 2,
        chamfer2 = (insert_ring3_d(type) - insert_barrel_d(type)) / 2,
        ring2_h = ring1_h + chamfer1,
        gap = (length - ring1_h - ring2_h - chamfer2) / 3
    ) ring1_h + gap + ring2_h - d + insert_barrel_d(type);

module insert(type) { //! Draw specified insert
    length = insert_length(type);
    ring1_h = insert_ring1_h(type);

    chamfer1 = (insert_ring2_d(type) - insert_barrel_d(type)) / 2;
    chamfer2 = (insert_ring3_d(type) - insert_barrel_d(type)) / 2;
    ring2_h = ring1_h + chamfer1;
    gap = (length - ring1_h - ring2_h - chamfer2) / 3;

    vitamin(str("insert(", type[0], "): Heatfit insert M", insert_screw_diameter(type)));
    $fn = 64;
    thread_d = insert_screw_diameter(type);
    explode(20, offset = [0, 0, -5]) translate_z(eps) vflip() {
        r1 = thread_d / 2;
        r2 = insert_barrel_d(type) / 2;
        r3 = insert_ring3_d(type) / 2;
        r4 = insert_ring2_d(type) / 2;
        r5 = insert_outer_d(type) / 2;
        h1 = ring1_h;
        h2 = ring1_h + gap;
        h3 = ring1_h + gap + ring2_h;
        h4 = ring1_h + gap + ring2_h + gap;
        color(brass)
            rotate_extrude(convexity = 3)
                polygon([
                    [r1, 0],
                    [r1, length],
                    [r2, length],
                    [r3, length - chamfer2],
                    [r3, h4],
                    [r2, h4],
                    [r2, h3],
                    [r4, h3 - chamfer1],
                    [r4, h2],
                    [r2, h2],
                    [r2, h1],
                    [r5, h1],
                    [r5, 0],
                ]);

        if(show_threads)
            female_metric_thread(thread_d, metric_coarse_pitch(thread_d), length, center = false, colour = brass);
    }
}

module insert_hole(type, counterbore = 0, horizontal = false) { //! Make a hole to take an insert, ```counterbore``` is the extra length for the screw
    h = insert_hole_length(type);

    render(convexity = 2)
        if(horizontal) {
            teardrop_plus(r = insert_hole_radius(type), h = 2 * h);

            if(counterbore)
                teardrop_plus(r = insert_screw_diameter(type) / 2 + 0.1, h = 2 * (h + counterbore));
        }
        else {
            poly_cylinder(r = insert_hole_radius(type), h = 2 * h, center = true);

            if(counterbore)
                poly_cylinder(r = insert_screw_diameter(type) / 2 + 0.1, h = 2 * (h + counterbore), center = true);
        }
}

function insert_boss_radius(type, wall) = corrected_radius(insert_hole_radius(type)) + wall; //! Compute the outer radius of an insert boss

module insert_boss(type, z, wall = 2 * extrusion_width) { //! Make a boss to take an insert
    ir = insert_hole_radius(type);
    or = corrected_radius(ir) + wall;

    module shape()
        hull()
            poly_ring(or, ir);

    linear_extrude(z)
        poly_ring(or, ir);

    linear_extrude(z - insert_hole_length(type))
        difference() {
            shape();

            poly_circle(insert_screw_diameter(type) / 2 + 0.1);
        }

    if(z > insert_hole_length(type) + 2 * layer_height)
        linear_extrude(2 * layer_height)       // cap the end if room
            shape();
}

module insert_lug(insert, wall, counter_bore = 0, extension = 0, corner_r = 0, flying = true) { //! Make a flying insert lug, see [ssr_shroud](#Ssr_shroud)
    boss_r = insert_boss_radius(insert, wall);
    boss_h = insert_hole_length(insert);
    boss_h2 = boss_h + counter_bore;

    module shape() {
        module _shape()
            hull() {
                circle(boss_r);

                translate([boss_r + extension - eps, 0])
                    square([eps, 2 * boss_r], center = true);
            }

        if(corner_r)
            intersection() {
                _shape();

                translate([boss_r + extension - corner_r, 0])
                    rotate(-45)
                        quadrant(w = 100, r = corner_r - eps, center = true);
            }
        else
            _shape();
    }

    translate_z(-boss_h)
        linear_extrude(boss_h)
             difference() {
                shape();

                poly_circle(insert_hole_radius(insert));
            }

    // insert boss counter_bore
    translate_z(-boss_h2) {
        linear_extrude(counter_bore + eps)
             difference() {
                shape();

                poly_circle(insert_screw_diameter(insert) / 2 + 0.1);
            }

        // support cone
        if(flying)
            hull() {
                linear_extrude(eps)
                    shape();

                translate([boss_r + extension - wall - eps, 0, - (2 * boss_r + extension - wall)])
                    cube(eps, center = true);
            }
    }
}