esphome-samsung-vfd/case/vfd-case.scad

// Desk case for the Samsung 20L203 2x20 VFD and a WEMOS D1 R1 (UNO-sized ESP8266).
//
// Three parts, all printable without supports:
//   body   sides, top and back wall (DC jack + USB cut-outs). Print upside down, top on the bed.
//   bezel  15 degree front panel with the window and the display bosses. Print face down.
//   base   floor with the board standoffs. Print flat.
//
// Assembly:
//   1. Melt M3 heat-set inserts into: 4 display bosses + 2 feet on the bezel,
//      2 rear corner bosses in the body, 4 board standoffs on the base.
//   2. Bolt the display to the bezel from behind (4x M3x8).
//   3. Screw the D1 board onto the base (4x M3x6).
//   4. Slide the bezel (with display) up into the body's side grooves from below.
//   5. Wire up, put the body on the base and screw it together from below (4x M3x8).
//
// Render one part:  openscad -D 'part="body"' -o body.stl vfd-case.scad
// Parts: "assembly" (preview with dummy display + board), "body", "bezel", "base",
//        "check_*" (collision checks, see the end of this file).

part = "assembly";
section_x = 130;        // cut position for part = "section"

/* [Case] */
tilt = 15;              // display tilt back from upright, degrees
wall = 3;               // side, top and back wall thickness
lip = 1.5;              // how far the bezel sits behind the front edge of the body
bezel_t = 3;            // bezel thickness
groove = 1.5;           // how deep the bezel edges sit in the side walls
clr = 0.3;              // fit clearance for sliding / mating parts
base_t = 3.5;           // base plate thickness
depth = 112;            // outer depth (front bottom edge to back)
top_margin = 4;         // bezel above the display's top edge (along the panel)

/* [Display module, datasheet 4.10] */
disp_w = 190;
disp_h = 64;
disp_hole_inset = 4;    // hole centres from the PCB edges (182 x 56 spacing)
glass_x0 = 3.0;         // glass left edge from PCB left edge (datasheet front view)
glass_y0 = 7.85;        // glass bottom edge from PCB bottom edge (datasheet front view)
glass_w = 175.2;
glass_h = 48.3;
glass_depth = 12.0;     // glass front face to PCB front face
glass_gap = 0.5;        // air gap between bezel and glass (datasheet asks for one)
pcb_t = 1.6;
disp_back = 11;         // components behind the display PCB
disp_raise = 14;        // PCB bottom edge, measured along the panel from the bottom
disp_rotated = true;    // display turned 180 deg from the datasheet's front view
                        // (jumper header on the left seen from the front); the
                        // glass is off-centre, so this moves the bosses 8.8 mm

/* [Window] */
win_w = 156;
win_h = 36;
win_r = 2;
win_chamfer = 1.5;

/* [Heat-set inserts, M3] */
insert_d = 4.0;         // hole for the insert
insert_depth = 6;
boss_d = 7;             // display bosses (larger would touch the glass)
screw_d = 3.4;          // M3 clearance
head_d = 6.2;           // M3 head counterbore in the base
head_depth = 2;

/* [WEMOS D1 R1 (Arduino UNO footprint)] */
board_l = 68.58;        // along the case depth, connector edge at the back
board_w = 53.34;
board_gap = 0.5;        // board edge to back wall
standoff_h = 6;
standoff_d = 7;
// UNO hole positions: (distance from the connector edge, distance from the jack side)
board_holes = [[13.97, 2.54], [15.24, 50.8], [66.04, 7.62], [66.04, 35.56]];
jack_pos = 7.6;         // DC jack centre from the board's jack-side edge
jack_cut = [12, 13];    // width, height (from 0.5 below the PCB top)
usb_pos = 38.1;         // micro-USB centre from the jack-side edge -- measure yours!
usb_cut = [12, 8];      // width, height (centred 1.6 above the PCB top)
board_comp_h = 10;      // tallest part on the board (dummy for the collision check)

$fn = 48;

// ---------- derived ----------
// glass position from the PCB's bottom-left corner as mounted (front view)
gl_x = disp_rotated ? disp_w - glass_x0 - glass_w : glass_x0;
gl_y = disp_rotated ? disp_h - glass_y0 - glass_h : glass_y0;
gx_c = gl_x + glass_w / 2;                            // glass centre from PCB left
inner_w = 2 * (max(gx_c, disp_w - gx_c) + 1.5);       // window centred, 1.5 mm side clearance
outer_w = inner_w + 2 * wall;
disp_x0 = inner_w / 2 - gx_c;                         // PCB left edge, x
z_top_in = (disp_raise + disp_h + top_margin) * cos(tilt);   // top wall underside
height = z_top_in + wall;
n_bezel_in = lip + bezel_t;                           // bezel inner face (local N)
n_glass = n_bezel_in + glass_gap;
n_pcb = n_glass + glass_depth;
win_s = disp_raise + gl_y + glass_h / 2;          // window centre along the panel
board_x0 = inner_w / 2 - board_w / 2;
board_conn_y = depth - wall - board_gap;              // y of the board's connector edge
pcb_top_z = standoff_h + pcb_t;
foot_n = n_bezel_in + 6;                              // insert axis in the bezel feet
foot_y = foot_n / cos(tilt);
foot_xs = [inner_w * 0.25, inner_w * 0.75];
rear_boss = 9;                                        // rear corner boss block size
rear_screws = [[rear_boss / 2, depth - wall - rear_boss / 2],
               [inner_w - rear_boss / 2, depth - wall - rear_boss / 2]];
base_screws = concat([for (x = foot_xs) [x, foot_y]], rear_screws);

echo(str("Outer size: ", outer_w, " x ", depth, " x ", height + base_t, " mm (W x D x H)"));

// Panel-local frame: X = across, S = up the panel from the bottom front edge,
// N = into the case from the body's front plane. The matrix is its own inverse.
M = [[1, 0, 0, 0],
     [0, sin(tilt), cos(tilt), 0],
     [0, cos(tilt), -sin(tilt), 0],
     [0, 0, 0, 1]];
module panel() multmatrix(M) children();

module rrect(w, h, r) {
    offset(r) square([w - 2 * r, h - 2 * r], center = true);
}

// 2D side profile (y, z) extruded along x.
module side_extrude(w) rotate([90, 0, 90]) linear_extrude(w) children();

// ---------- body ----------
module body() {
    difference() {
        union() {
            translate([-wall, 0, 0]) side_extrude(outer_w)
                polygon([[0, 0], [depth, 0], [depth, height], [height * tan(tilt), height]]);
        }
        // cavity, open at the front and bottom
        translate([0, -50, -1]) cube([inner_w, depth - wall + 50, z_top_in + 1]);
        // bezel grooves in the side walls
        intersection() {
            panel() translate([-groove - clr, -50, lip]) cube([inner_w + 2 * (groove + clr), 300, bezel_t + clr]);
            translate([-50, -50, -1]) cube([inner_w + 100, depth + 100, z_top_in + 1]);
        }
        // DC jack and USB
        for (c = [[jack_pos, jack_cut, pcb_top_z - 0.5 + jack_cut[1] / 2],
                  [usb_pos, usb_cut, pcb_top_z + 1.6]])
            translate([board_x0 + c[0], depth - wall / 2, c[2]])
                rotate([90, 0, 0]) linear_extrude(wall + 2, center = true) rrect(c[1][0], c[1][1], 1.5);
        // top vents over the back half
        for (i = [0 : 3]) translate([inner_w / 2, depth - wall - 14 - i * 8, height - wall / 2])
            linear_extrude(wall + 2, center = true) rrect(inner_w - 50, 3, 1.4);
    }
    // rear corner bosses for the base screws, chamfered up into the walls
    for (p = rear_screws) {
        x0 = p[0] < inner_w / 2 ? 0 : inner_w - rear_boss;
        xw = p[0] < inner_w / 2 ? 0 : inner_w - 0.01;
        difference() {
            hull() {
                translate([x0, depth - wall - rear_boss, 0]) cube([rear_boss, rear_boss, 10]);
                translate([xw, depth - wall - 0.01, 0]) cube([0.01, 0.01, 10 + rear_boss]);
                translate([x0, depth - wall - 0.01, 0]) cube([rear_boss, 0.01, 10 + rear_boss]);
                translate([xw, depth - wall - rear_boss, 0]) cube([0.01, rear_boss, 10 + rear_boss]);
            }
            translate([p[0], p[1], -1]) cylinder(d = insert_d, h = insert_depth + 1);
        }
    }
}

// ---------- bezel ----------
display_holes = [for (hx = [disp_hole_inset, disp_w - disp_hole_inset])
                 for (hy = [disp_hole_inset, disp_h - disp_hole_inset])
                 [disp_x0 + hx, disp_raise + hy]];

module bezel() {
    difference() {
        intersection() {
            panel() union() {
                // plate
                translate([-groove + clr, -50, lip]) cube([inner_w + 2 * (groove - clr), 300, bezel_t]);
                // display bosses, from the bezel to the PCB front face
                for (h = display_holes) translate([h[0], h[1], n_bezel_in - 0.01])
                    cylinder(d = boss_d, h = n_pcb - n_bezel_in + 0.01);
                // feet that take the front base screws
                for (x = foot_xs) translate([x - 6, -10, n_bezel_in - 0.01]) cube([12, 22, 12]);
            }
            // flat bottom on the base, flat top against the top wall
            translate([-50, -50, 0]) cube([inner_w + 100, depth + 100, z_top_in - clr]);
        }
        // window, chamfered on the front
        panel() translate([inner_w / 2, win_s, 0]) {
            translate([0, 0, lip - 1]) linear_extrude(bezel_t + 2) rrect(win_w, win_h, win_r);
            hull() {
                translate([0, 0, lip - 0.01]) linear_extrude(0.01) rrect(win_w + 2 * win_chamfer, win_h + 2 * win_chamfer, win_r + win_chamfer);
                translate([0, 0, lip + win_chamfer]) linear_extrude(0.01) rrect(win_w, win_h, win_r);
            }
        }
        // inserts in the display bosses
        panel() for (h = display_holes) translate([h[0], h[1], n_pcb - insert_depth])
            cylinder(d = insert_d, h = insert_depth + 1);
        // inserts in the feet (vertical)
        for (x = foot_xs) translate([x, foot_y, -1]) cylinder(d = insert_d, h = insert_depth + 1);
    }
}

// ---------- base ----------
module base() {
    difference() {
        union() {
            translate([-wall, 0, -base_t]) cube([outer_w, depth, base_t]);
            // locating rim inside the side and back walls (stops short of the bezel and bosses)
            rim_y0 = 20;
            for (x = [clr, inner_w - clr - 1.6])
                translate([x, rim_y0, -0.01]) cube([1.6, depth - wall - rear_boss - clr - rim_y0, 2]);
            translate([rear_boss + clr, depth - wall - clr - 1.6, -0.01])
                cube([inner_w - 2 * (rear_boss + clr), 1.6, 2]);
            // board standoffs
            for (h = board_holes) translate(board_xy(h)) cylinder(d = standoff_d, h = standoff_h);
            // cable-tie anchor for the MAX3232 / display cable
            translate([inner_w / 2, board_conn_y - board_l - 4.5, 0]) tie_anchor();
        }
        // screws into the body / bezel inserts, counterbored from below
        for (p = base_screws) translate([p[0], p[1], -base_t - 1]) {
            cylinder(d = screw_d, h = base_t + 2);
            cylinder(d = head_d, h = head_depth + 1);
        }
        // board standoff inserts
        for (h = board_holes) translate(board_xy(h)) translate([0, 0, standoff_h - insert_depth + 0.5])
            cylinder(d = insert_d, h = insert_depth);
        // vents under the display
        for (i = [0 : 2]) translate([inner_w / 2, 20 + i * 7, -base_t / 2])
            linear_extrude(base_t + 2, center = true) rrect(inner_w - 70, 3, 1.4);
    }
}

function board_xy(h) = [board_x0 + h[1], board_conn_y - h[0], 0];

module tie_anchor() {
    difference() {
        translate([-5, -3, 0]) cube([10, 6, 5]);
        translate([-2.5, -4, -0.01]) cube([5, 8, 3.2]);
    }
}

// ---------- dummies for the preview and the collision checks ----------
module display_dummy() {
    panel() {
        translate([disp_x0 + gl_x, disp_raise + gl_y, n_glass + 0.01])
            cube([glass_w, glass_h, glass_depth - 0.02]);
        translate([disp_x0, disp_raise, n_pcb + 0.01]) difference() {
            cube([disp_w, disp_h, pcb_t + disp_back]);
            for (hx = [disp_hole_inset, disp_w - disp_hole_inset])
                for (hy = [disp_hole_inset, disp_h - disp_hole_inset])
                    translate([hx, hy, -1]) cylinder(d = 3.5, h = pcb_t + 2);
        }
    }
}

module board_dummy() {
    translate([board_x0, board_conn_y - board_l, standoff_h + 0.01]) difference() {
        union() {
            cube([board_w, board_l, pcb_t]);
            translate([2, 2, pcb_t]) cube([board_w - 4, board_l - 4, board_comp_h]);
            // DC jack, sticking out 1 mm past the board edge
            translate([jack_pos - 4.5, board_l - 14, pcb_t]) cube([9, 15, 11]);
        }
        for (h = board_holes) translate([h[1], board_l - h[0], -1]) cylinder(d = 3.2, h = pcb_t + 2);
    }
}

// ---------- output ----------
if (part == "assembly") {
    color("SlateGray", 0.5) body();
    color("DimGray") bezel();
    color("Gainsboro") base();
    color("SeaGreen") display_dummy();
    color("SteelBlue") board_dummy();
} else if (part == "section") {
    // assembly cut at x = section_x, for checking the inside
    intersection() {
        union() {
            color("SlateGray") body();
            color("DimGray") bezel();
            color("Gainsboro") base();
            color("SeaGreen") display_dummy();
            color("SteelBlue") board_dummy();
        }
        translate([section_x, -50, -50]) cube([500, 500, 500]);
    }
} else if (part == "body") {
    translate([0, depth, height]) rotate([180, 0, 0]) body();      // top on the bed
} else if (part == "bezel") {
    translate([0, 0, -lip]) multmatrix(M) bezel();                 // front face on the bed
} else if (part == "base") {
    translate([0, 0, base_t]) base();
}
// Collision checks: each must render as an empty object.
else if (part == "check_body_bezel") intersection() { body(); bezel(); }
else if (part == "check_body_display") intersection() { body(); display_dummy(); }
else if (part == "check_bezel_display") intersection() { bezel(); display_dummy(); }
else if (part == "check_body_base") intersection() { body(); base(); }
else if (part == "check_bezel_base") intersection() { bezel(); base(); }
else if (part == "check_board") intersection() { union() { body(); bezel(); base(); display_dummy(); } board_dummy(); }
else if (part == "check_display_base") intersection() { base(); display_dummy(); }
// The bezel slides in from below along the panel: sweep it (with the display) down and check.
else if (part == "check_insertion") intersection() {
    body();
    for (k = [5 : 5 : 80]) translate(-k * [0, sin(tilt), cos(tilt)]) { bezel(); display_dummy(); }
}