// Slide-on wall mount for Samsung Galaxy Tab S6 (SM-T860/T865/T867), landscape.
// Three parts. Render each with:  openscad -D 'part="plate"' -o plate.stl mount.scad
// Units: mm. Coordinate system for the plate: x = across the wall (0 = tablet centreline),
// y = up the wall (0 = the tablet's bottom edge when seated), z = out from the wall toward the room.
// Tablet: 244.5 x 159.5 x 5.7, four charging pads centred on its bottom edge, ~3.3 mm pitch.

part = "plate";   // "plate" | "block" | "frame" | "assembly"
$fn = 64;

// ---------- shared numbers ----------
tab_w = 244.5;  tab_h = 159.5;  tab_t = 5.7;
plate_t   = 3;                 // plate body thickness
plate_w   = 120;  plate_h = 110;
plate_y0  = 25;                // plate bottom edge, above the tablet's bottom edge
tongue_h  = 70;  tongue_w_base = 78;  tongue_w_top = 84;  tongue_t = 3;
tongue_y0 = plate_y0 + 20;     // tongue bottom edge (its top edge is 20 below the plate top)
stem_w    = 70;                // stem from plate bottom down to the tablet edge
hole_d    = 16;                // cable hole, big enough to pass the buck converter
hole_y    = 35;
screw_d   = 4.5;  csk_d = 9;   // #8 wood screw, countersunk
clear     = 0.3;               // per-side sliding clearance (FDM: outer walls run oversize, openings undersize)
standoff  = plate_t + tongue_t + 0.5;   // wall to tablet back, ~6.5

// pin block
pins      = 4;  pin_pitch = 3.3;  pin_hole_d = 2.4;   // drill to 2.5 for the Treedix pins
blk_w = 20;  blk_depth = 8;  blk_z0 = 0.5;  blk_top = 12.0;   // body below the tablet edge: from 0.5 off the wall to 0.2 inside the glass plane
chan_w = 3.5;  chan_d = 1.5;                          // wire channel on the wall-side faces (block back, plate back)
blk_gap = 1.0;                                        // shoulder sits this far below the edge = pin working compression
pocket_d = 1.0;                                       // solder pocket depth; pin (9 mm) seats on its floor -> tip = 9-(8-1) = 2 mm proud
pin_z  = standoff + tab_t/2;                          // pin axis at mid-thickness of the tablet edge
slot_len = 60;  slot_y = 8;  slot_w_face = 5;  slot_w_deep = 7;  slot_depth = 2;   // dovetail slot in the stem
bridge_t = 2;

// U-frame (glued to the tablet's back). It occupies z = standoff-fr_t .. standoff, i.e. shifted fr_off above the tongue's base,
// so its dovetail opening is cut for the tongue's width at those heights (flanks are 45 deg: width grows 2 mm per mm of height).
fr_w = 110;  fr_h = 100;  fr_t = 3;  fr_bar = 15;  fr_arm = 15;
fr_off = standoff - (plate_t + tongue_t);        // 0.5
fr_open_wall = tongue_w_base + 2*fr_off + 2*clear;   // opening at the frame's wall-side face
fr_open_tab  = fr_open_wall + 2*fr_t;                // opening at the glue face (45 deg)

// ---------- helpers ----------
module dovetail_prism(w_bottom, w_top, len, height, y0=0, z0=0) {
    // trapezoid in x-z, extruded along y from y0 for len
    hull() {
        translate([-w_bottom/2, y0, z0])       cube([w_bottom, len, 0.01]);
        translate([-w_top/2,    y0, z0+height]) cube([w_top,    len, 0.01]);
    }
}
module dovetail_x(len, w_face, w_deep, z_face, depth, yc) {
    // groove/rail running along x, centred on y=yc; width w_face at z_face, w_deep at z_face-depth
    hull() {
        translate([-len/2, yc - w_face/2, z_face - 0.01])   cube([len, w_face, 0.01]);
        translate([-len/2, yc - w_deep/2, z_face - depth])  cube([len, w_deep, 0.01]);
    }
}
module csk_hole(x, y) {
    translate([x, y, -1]) cylinder(d=screw_d, h=plate_t+2);
    translate([x, y, plate_t - (csk_d-screw_d)/2]) cylinder(d1=screw_d, d2=csk_d, h=(csk_d-screw_d)/2 + 0.01);
}

// ---------- PART A: wall plate ----------
module plate() {
    difference() {
        union() {
            // body
            translate([-plate_w/2, plate_y0, 0]) cube([plate_w, plate_h, plate_t]);
            // stem down to the tablet edge
            translate([-stem_w/2, 0, 0]) cube([stem_w, plate_y0 + 0.01, plate_t]);
            // tongue: dovetail, wider at the top (room side) than at its base
            dovetail_prism(tongue_w_base, tongue_w_top, tongue_h, tongue_t, y0=tongue_y0, z0=plate_t);
        }
        // screw holes, countersunk from the room side
        for (sx=[-1,1], sy=[0,1]) csk_hole(sx*50, sy==0 ? plate_y0+8 : plate_y0+plate_h-8);
        // cable hole
        translate([0, hole_y, -1]) cylinder(d=hole_d, h=plate_t+2);
        // dovetail slot for the pin block, cut into the room-side face of the stem, along x
        translate([0,0,0.02]) dovetail_x(slot_len, slot_w_face, slot_w_deep, plate_t, slot_depth, slot_y + slot_w_deep/2);
        // wire groove on the wall side, routed around the slot: behind the block along the stem bottom (y 1..4.5),
        // over to the stem's right edge, up past the slot, then across to the cable hole
        translate([-chan_w/2, -0.01, -0.01]) cube([35 + chan_w/2, 4.5, chan_d]);
        translate([35 - chan_w, 1, -0.01])   cube([chan_w, 36, chan_d]);
        translate([6, 37 - chan_w, -0.01])   cube([29, chan_w, chan_d]);
    }
}

// ---------- PART B: pin block ----------
module block() {
    difference() {
        union() {
            // rail that rides in the stem's slot (dovetail, wider at the bottom)
            dovetail_x(blk_w, slot_w_face - 2*clear, slot_w_deep - 2*clear, plate_t, slot_depth, slot_y + slot_w_deep/2);
            // bridge over the stem face, from the rail down to the block body
            translate([-blk_w/2, -blk_depth - blk_gap, plate_t]) cube([blk_w, blk_depth + blk_gap + slot_y + slot_w_deep + 1, bridge_t]);
            // body below the tablet edge, reaching back to (almost) the wall so nothing shows behind it
            translate([-blk_w/2, -blk_depth - blk_gap, blk_z0]) cube([blk_w, blk_depth, blk_top - blk_z0]);
        }
        // four pin holes, axis along y, from the shoulder down through the body
        for (i=[0:pins-1]) {
            x = (i - (pins-1)/2) * pin_pitch;
            translate([x, -blk_depth - blk_gap - 1, pin_z]) rotate([-90,0,0]) cylinder(d=pin_hole_d, h=blk_depth + 2);
        }
        // solder pocket on the bottom face for the pin tails and wires
        translate([-blk_w/2 + 2, -blk_depth - blk_gap - 0.01, pin_z - 2.5]) cube([blk_w - 4, pocket_d + 0.01, 5]);
        // wire channel: from the pocket, across the bottom face to the wall side, then up the back face to the stem
        translate([-chan_w/2, -blk_depth - blk_gap - 0.01, blk_z0 - 0.01]) cube([chan_w, pocket_d + 0.02, pin_z - blk_z0]);
        translate([-chan_w/2, -blk_depth - blk_gap - 0.01, blk_z0 - 0.01]) cube([chan_w, blk_depth + blk_gap + 0.02, chan_d + 0.01]);
    }
}

// ---------- PART C: U-frame, glued to the tablet's back ----------
// Frame coords: z=0 is the face glued to the tablet, z=fr_t faces the wall.
// The opening is a dovetail matching the tongue: wide at the tablet face, narrow at the wall face,
// so the arms hook under the tongue's flanks.
module frame() {
    difference() {
        translate([-fr_w/2, 0, 0]) cube([fr_w, fr_h, fr_t]);
        // opening: open at the bottom (y<0), closed by the top bar at y = fr_h - fr_bar
        hull() {
            translate([-fr_open_tab/2,  -1, -0.01])         cube([fr_open_tab,  fr_h - fr_bar + 1, 0.01]);
            translate([-fr_open_wall/2, -1, fr_t - 0.005])  cube([fr_open_wall, fr_h - fr_bar + 1, 0.01]);
        }
    }
}

// ---------- assembly preview (not for printing) ----------
module assembly() {
    color("slategray") plate();
    color("peru") block();
    // frame sits in the same layer as the tongue, hanging with its top bar on the tongue's top edge
    color("steelblue") translate([0, tongue_y0 + tongue_h + clear - (fr_h - fr_bar), standoff]) mirror([0,0,1]) frame();
    // tablet, translucent
    color("black", 0.25) translate([-tab_w/2, 0, standoff]) cube([tab_w, tab_h, tab_t]);
}

if (part == "plate") plate();
else if (part == "block") translate([0,0,blk_depth+blk_gap]) rotate([90,0,0]) block();   // stood on its bottom face for printing
else if (part == "frame") frame();
else assembly();