NopSCADlib/printed/box.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/>.
//

//
//! A box made from routed or laser cut sheet sheets and printed profiles and bezels. It can be arbitrarily large
//! compared to the 3D printed parts because they can be cut into interlocking sections and solvent welded
//! together. The box panels can be customised to have holes and parts mounted on them by overriding the
//! definitions of `box_base()`, `box_front()`, etc.
//!
//! `box.scad` should be ```use```d and `box_assembly.scad` ```include```d.
//!
//! A box is defined with a list that specifies the inside dimensions, top, bottom and side sheet materials, the
//! screw type and printed part wall thickness. This diagram shows how the various dimensions are labelled:
//! ![](docs/box.png)
//!
//! Normally the side sheets are the same type but they can be overridden individually as long as the substitute has the same thickness.
//
include <../core.scad>
use <../vitamins/sheet.scad>
use <../vitamins/screw.scad>
use <../vitamins/washer.scad>

include <../vitamins/inserts.scad>
use <../utils/quadrant.scad>

bezel_clearance = 0.2;
sheet_end_clearance = 1;
sheet_slot_clearance = 0.2;

function box_screw(type)     = type[0]; //! Screw type to be used at the corners
function box_wall(type)      = type[1]; //! Wall thickness of 3D parts
function box_sheets(type)    = type[2]; //! Sheet type used for the sides
function box_top_sheet(type) = type[3]; //! Sheet type for the top
function box_base_sheet(type)= type[4]; //! Sheet type for the bottom
function box_feet(type)      = type[5]; //! True to enable feet on the bottom bezel
function box_width(type)     = type[6]; //! Internal width
function box_depth(type)     = type[7]; //! Internal depth
function box_height(type)    = type[8]; //! Internal height

function box_bezel_clearance(type) = bezel_clearance;

function box_corner_gap(type) = 3; //! Gap between box_sheets at the corners to connect inside and outside profiles
function box_profile_overlap(type) = 3 + sheet_end_clearance / 2;

function box_washer(type) = screw_washer(box_screw(type));
function box_insert(type) = screw_insert(box_screw(type));

function box_hole_inset(type) = washer_radius(box_washer(type)) + 1;
function box_insert_r(type) = insert_hole_radius(box_insert(type));
function box_insert_l(type) = insert_length(box_insert(type));
function box_boss_r(type) = ceil(corrected_radius(box_insert_r(type)) + box_wall(type));

function box_sheet_slot(type) = sheet_thickness(box_sheets(type)) + sheet_slot_clearance; // add some clearance
function box_corner_overlap(type) = box_wall(type);

function box_corner_rad(type) = box_sheet_slot(type) - sheet_slot_clearance / 2 + box_corner_gap(type) + box_corner_overlap(type);
function box_sheet_r(type) = box_corner_rad(type) - box_sheet_slot(type) - box_corner_overlap(type);

function box_screw_length(type, top) = screw_longer_than(2 * washer_thickness(box_washer(type))
                                                    + sheet_thickness(top ? box_top_sheet(type) : box_base_sheet(type))
                                                    + box_corner_gap(type) + box_profile_overlap(type) + box_insert_l(type) - 1);

function box_wall_clearance(type) = box_sheet_slot(type) / 2 - sheet_thickness(box_sheets(type)) / 2;
function box_margin(type) = box_profile_overlap(type) + box_corner_gap(type); //! How much the bezel intrudes on the specified height
function box_intrusion(type) = box_hole_inset(type) + box_boss_r(type); //! Corner profile intrusion
function sheet_reduction(type) = 2 * box_corner_gap(type) + sheet_end_clearance;
function box_outset(type) = box_sheet_slot(type) + box_wall(type) - sheet_slot_clearance / 2;  //! How much the bezel expands the specified internal size
function box_inset(type) = box_wall(type) + sheet_slot_clearance / 2; //! How much the bezel intrudes on the specified width and length, away from the corners
function box_bezel_height(type, bottom) = //! Bezel height for top or bottom
    let(t1 = sheet_thickness(box_base_sheet(type)), t2 = sheet_thickness(box_top_sheet(type)))
        box_corner_rad(type) + box_profile_overlap(type) + (bottom ? max(t1, t2) : t2) - sheet_thickness(box_sheets(type));

grill_hole = 5;
grill_gap = 1.9;
module grill(width, height, r = 1000, poly = false, h = 0) { //! A staggered array of 5mm holes to make grills in sheets. Can be constrained to be circular. Set ```poly``` ```true``` for printing, ```false``` for milling.
    nx = floor(width / (grill_hole + grill_gap));
    xpitch = width / nx;
    ny = floor(height / ((grill_hole + grill_gap) * cos(30)));
    ypitch = height / ny;

    extrude_if(h)
        for(y = [0 : ny - 1], x = [0 : nx - 1 - (y % 2)]) {
            x = -width / 2 + (x + 0.5 + (y % 2) / 2) * xpitch;
            y = -height / 2 + (y + 0.5) * ypitch;
            if(sqrt(sqr(x) + sqr(y)) + grill_hole / 2 <= r)
                translate([x, y])
                    if(poly)
                        poly_circle(r = grill_hole / 2);
                    else
                        circle(d = grill_hole);
        }
}

module box_corner_profile_2D(type) { //! The 2D shape of the corner profile.
    t = box_sheet_slot(type);
    difference() {
        union() {
            quadrant(box_hole_inset(type) + box_boss_r(type), box_boss_r(type));     // inside corner

            translate([box_corner_gap(type) + box_profile_overlap(type), box_corner_gap(type) + box_profile_overlap(type)])
                rotate(180)
                    quadrant(box_profile_overlap(type) + box_corner_rad(type), box_corner_rad(type)); // outside corner
        }
        translate([box_corner_gap(type), -t + sheet_slot_clearance / 2])
            square([100, t]);

        translate([-t + sheet_slot_clearance / 2, box_corner_gap(type)])
            square([t, 100]);
    }
}

module box_corner_profile(type) { //! Generates the corner profile STL for 3D printing.
    stl("box_corner_profile");

    length = box_height(type) - 2 * box_margin(type);
    difference() {
        linear_extrude(height = length, center = true, convexity = 5)
            box_corner_profile_2D(type);

        for(z = [-1, 1])
            translate([box_hole_inset(type), box_hole_inset(type), z * length / 2])
                insert_hole(box_insert(type), 5);
    }
}

module box_corner_profile_section(type, section, sections) { //! Generates interlocking sections of the corner profile to allow it to be taller than the printer
    overlap = 4;
    length = box_height(type) - 2 * box_margin(type);
    section_length = round_to_layer((length - overlap) / sections);
    last_section = section >= sections - 1;
    h = last_section ? length - (sections - 1) * section_length : section_length;
    overlap_wall = 2;

    difference() {
        union() {
            linear_extrude(height = h, convexity = 5)
                box_corner_profile_2D(type);

            if(!last_section)                              // male end always at the top
                translate_z(section_length - 1)
                    for(i = [0 : 1], offset = i * layer_height)
                        linear_extrude(height = overlap + 1 - offset)
                            offset(1 + offset - layer_height)
                                offset(-overlap_wall - 1)
                                    box_corner_profile_2D(type);
        }
        if(section > 0)
            translate_z(last_section ? h : 0) {       // female at bottom unless last section
                linear_extrude(height = 2 * (overlap + layer_height), center = true, convexity = 5)
                    offset(-overlap_wall)
                        box_corner_profile_2D(type);

                linear_extrude(height = 2 * layer_height, center = true, convexity = 5)
                    offset(-overlap_wall + layer_height)
                        box_corner_profile_2D(type);
            }
        if(!section || last_section)                        // insert holes always at the bottom
            translate([box_hole_inset(type), box_hole_inset(type)])
                insert_hole(box_insert(type), 5);
    }
}

module box_corner_quadrants(type, width, depth)
    for(corner = [0:3]) {
        x = [-1,1,1,-1][corner];
        y = [-1,-1,1,1][corner];

        translate([x * width / 2, y * depth / 2, 0])
            rotate(corner * 90)
                quadrant(box_intrusion(type), box_boss_r(type));
    }

module box_bezel(type, bottom) { //! Generates top and bottom bezel STLs
    stl(bottom ? "bottom_bezel" : "top_bezel");
    feet = bottom && box_feet(type);
    t = box_sheet_slot(type);
    outset =  box_outset(type);
    inner_r = box_sheet_r(type);
    foot_height = box_corner_gap(type) + sheet_thickness(box_base_sheet(type)) + washer_thickness(box_washer(type)) + screw_head_height(box_screw(type)) + box_profile_overlap(type) + 2;
    foot_length = box_corner_rad(type) * 2;
    height = box_bezel_height(type, bottom);
    foot_extension = foot_height - height;

    difference() {
        translate_z(-box_profile_overlap(type)) difference() {
            rounded_rectangle([box_width(type) + 2 * outset, box_depth(type) + 2 * outset, feet ? foot_height : height], box_corner_rad(type), false);
            //
            // Remove edges between the feet
            //
            if(feet)
                hull() {
                    translate_z(height + 0.5)
                        cube([box_width(type) - 2 * foot_length, box_depth(type) + 2 * outset + 1, 1], center = true);

                    translate_z(foot_height + 1)
                        cube([box_width(type) - 2 * (foot_length - foot_extension), box_depth(type) + 2 * outset + 1, 1], center = true);
                }
            if(feet)
                hull() {
                    translate_z(height + 0.5)
                        cube([box_width(type) + 2 * outset + 1, box_depth(type) - 2 * foot_length, 1], center = true);

                    translate_z(foot_height + 1)
                        cube([box_width(type) + 2 * outset + 1, box_depth(type) - 2 * (foot_length - foot_extension), 1], center = true);
                }
        }
        //
        // slots for side panels
        //
        translate_z(-box_profile_overlap(type))
            linear_extrude(height = 2 * box_profile_overlap(type), center = true)
                for(i = [-1, 1]) {
                    translate([i * (box_width(type) / 2 + t / 2 - sheet_slot_clearance / 2), 0])
                         square([t, box_depth(type) - 2 * box_corner_gap(type)], center = true);

                    translate([0, i * (box_depth(type) / 2 + t / 2 - sheet_slot_clearance / 2)])
                         square([box_width(type) - 2 * box_corner_gap(type), t], center = true);
                }
        //
        // recess for top / bottom panel
        //
        translate_z(box_corner_gap(type))
            rounded_rectangle([box_width(type) + bezel_clearance, box_depth(type) + bezel_clearance, height], inner_r + bezel_clearance / 2, false);
        //
        // leave plastic over the corner profiles
        //
        translate_z(-box_profile_overlap(type) - 1)
            linear_extrude(height = box_profile_overlap(type) + box_corner_gap(type) + 2)
                union() {
                    difference() {
                        square([box_width(type) - 2 * box_inset(type),
                                box_depth(type) - 2 * box_inset(type)], center = true);

                        box_corner_quadrants(type, box_width(type), box_depth(type));
                    }
                    box_screw_hole_positions(type)
                        poly_circle(screw_clearance_radius(box_screw(type)));
                }
     }
}

dowel_length = 20;
dowel_wall = extrusion_width * 3;
dowel_h_wall = layer_height * 6;


module box_bezel_section(type, bottom, rows, cols, x, y) { //! Generates interlocking sections of the bezel to allow it to be bigger than the printer
    w = (box_width(type) + 2 * box_outset(type)) / cols;
    h = (box_depth(type) + 2 * box_outset(type)) / rows;
    bw = box_outset(type) - bezel_clearance / 2;
    bw2 = box_outset(type) + box_inset(type);

    dw = bw - 2 * dowel_wall;
    dh = box_bezel_height(type, bottom) - dowel_h_wall;

    dh2 = box_profile_overlap(type) + box_corner_gap(type) - dowel_h_wall;

    end_clearance = 0.5;
    module male() {
        rotate([90, 0, 90])
            linear_extrude(height = dowel_length - 2 * end_clearance, center = true)
                difference() {
                    union() {
                        h = dh - layer_height;
                        h2 = dh2 - layer_height;
                        hull() {
                            translate([bw / 2, h / 2])
                                square([dw - 1, h], center = true);

                            translate([bw / 2, (h - 1) / 2])
                                square([dw, h - 1], center = true);
                        }

                        hull() {
                            translate([bw2 / 2, h2 / 2])
                                square([bw2 - 2 * dowel_wall - 1, h2], center = true);

                            translate([bw2 / 2, (h2 - 1) / 2])
                                square([bw2 - 2 * dowel_wall, h2 - 1], center = true);
                        }
                    }
                    translate([bw2 / 2, 0])
                        square([box_sheet_slot(type), 2 * box_profile_overlap(type)], center = true);
                }
    }

    module female() {
        union() {
            translate([0, bw / 2, dh / 2])
                cube([dowel_length, dw, dh], center = true);

            translate([0, bw2 / 2])
                cube([dowel_length, bw2 - 2 * dowel_wall, dh2 * 2], center = true);

            hull() {
                translate([0, bw / 2, dh / 2])
                    cube([2, dw, dh], center = true);

                translate([0, bw / 2, dh / 2])
                    cube([eps, dw + 2 * extrusion_width, dh], center = true);

            }
            hull() {
                translate([0, bw2 / 2, dh2 / 2])
                    cube([2, bw2 - 2 * dowel_wall, dh2], center = true);

                translate([0, bw2 / 2, dh2 / 2])
                    cube([eps, bw2 - 2 * dowel_wall + 2 * extrusion_width, dh2], center = true);

            }
        }
    }

    module support() {
        if(!$preview)
            translate([0, bw / 2 + dw / 2])
                cube([dowel_length / 2 - 0.25, 2 * extrusion_width + 0.2, dh2]);
    }

    union() {
        render() difference() {
            union() {
                clip(xmin = 0, xmax = w, ymin = 0, ymax = h)
                    translate([box_width(type) / 2 + box_outset(type) - x * w, box_depth(type) / 2 + box_outset(type) - y * h, box_profile_overlap(type)])
                        box_bezel(type, bottom);

                if(x < cols - 1 && y == 0)
                    translate([w, 0])
                        male();

                if(x > 0 && y == rows - 1)
                    translate([0, h])
                        rotate(180)
                            male();

                if(y < rows - 1 && x == cols - 1)
                    translate([w, h])
                        rotate(90)
                            male();

                if(y > 0 && x == 0)
                    rotate(-90)
                        male();
            }

            if(x < cols - 1 && y == rows - 1)
                translate([w, h])
                    rotate(180)
                        female();

            if(x > 0 && y == 0)
                female();

            if(y < rows - 1 && x == 0)
                translate([0, h])
                    rotate(-90)
                        female();

            if(y > 0 && x == cols - 1)
                translate([w, 0])
                    rotate(90)
                        female();
        }
        if(x < cols - 1 && y == rows - 1)
            translate([w, h])
                rotate(180)
                    support();

        if(x > 0 && y == 0)
            support();

        if(y < rows - 1 && x == 0)
            translate([0, h])
                rotate(-90)
                    support();

        if(y > 0 && x == cols - 1)
            translate([w, 0])
                rotate(90)
                    support();
    }
}


module box_screw_hole_positions(type)
    for(x = [-1, 1], y = [-1, 1])
        translate([x * (box_width(type) / 2 - box_hole_inset(type)), y * (box_depth(type) / 2 - box_hole_inset(type))])
            children();

module box_base_blank(type) { //! Generates a 2D template for the base sheet
    dxf("box_base");

    difference() {
        sheet_2D(box_base_sheet(type), box_width(type), box_depth(type), box_sheet_r(type));

        box_screw_hole_positions(type)
            drill(screw_clearance_radius(box_screw(type)), 0);
    }
}

module box_top_blank(type) {  //! Generates a 2D template for the top sheet
    dxf("box_top");

    difference() {
        sheet_2D(box_top_sheet(type), box_width(type), box_depth(type), box_sheet_r(type));

        box_screw_hole_positions(type)
            drill(screw_clearance_radius(box_screw(type)), 0);
    }
}

function subst_sheet(type, sheet) =
    let(s = box_sheets(type))
        sheet ? assert(sheet_thickness(sheet) == sheet_thickness(s)) sheet : s;

module box_shelf_blank(type, sheet = false) { //! Generates a 2D template for a shelf sheet
    dxf("box_shelf");

    difference() {
        sheet_2D(subst_sheet(type, sheet), box_width(type) - bezel_clearance, box_depth(type) - bezel_clearance, 1);

        offset(bezel_clearance / 2)
            box_corner_quadrants(type, box_width(type), box_depth(type));
    }
}

module box_left_blank(type, sheet = false) { //! Generates a 2D template for the left sheet, ```sheet``` can be set to override the type
    dxf("box_left");

    sheet_2D(subst_sheet(type, sheet), box_depth(type) - sheet_reduction(type), box_height(type) - sheet_reduction(type), 1);
}

module box_right_blank(type, sheet = false) { //! Generates a 2D template for the right sheet, ```sheet``` can be set to override the type
    dxf("box_right");

    sheet_2D(subst_sheet(type, sheet), box_depth(type) - sheet_reduction(type), box_height(type) - sheet_reduction(type), 1);
}

module box_front_blank(type, sheet = false) { //! Generates a 2D template for the front sheet, ```sheet``` can be set to override the type
    dxf("box_front");

    sheet_2D(subst_sheet(type, sheet), box_width(type) - sheet_reduction(type), box_height(type) - sheet_reduction(type), 1);
}

module box_back_blank(type, sheet = false) { //! Generates a 2D template for the back sheet, ```sheet``` can be set to override the type
    dxf("box_back");

    sheet_2D(subst_sheet(type, sheet), box_width(type) - sheet_reduction(type), box_height(type) - sheet_reduction(type), 1);
}

module box_base(type)  render_2D_sheet(box_base_sheet(type)) box_base_blank(type);  //! Default base, can be overridden to customise
module box_top(type)   render_2D_sheet(box_top_sheet(type))  box_top_blank(type);   //! Default top, can be overridden to customise
module box_back(type)  render_2D_sheet(box_sheets(type))     box_back_blank(type);  //! Default back, can be overridden to customise
module box_front(type) render_2D_sheet(box_sheets(type))     box_front_blank(type); //! Default front, can be overridden to customise
module box_left(type)  render_2D_sheet(box_sheets(type))     box_left_blank(type);  //! Default left side, can be overridden to customise
module box_right(type) render_2D_sheet(box_sheets(type))     box_right_blank(type); //! Default right side, can be overridden to customise