// =============================================================================
// SaltyBot — Prototype Base Plate  (Rev D — correct 270 × 240 mm envelope)
// Agent: sl-mechanical  |  2026-02-28  |  Fixes issue #18
//
// Laser-cut or CNC-routed flat plate (6 mm Al / 8 mm acrylic).
//
// PLATE DIMENSIONS (per spec, issue #18)
//   Width  (axle direction, X): 270 mm
//   Depth  (front-to-rear,  Y): 240 mm
//   Wheels extend beyond plate edges — expected.
//
// MOTOR AXLE GEOMETRY
//   Plate edge = axle entry point  (X = ±135 mm from plate centre)
//   Fork slot depth = 50 mm inward → axle C/L seated at X = ±85 mm
//   Axle-to-axle distance = 170 mm
//   Tires (Ø254 mm, 54 mm wide) at X = ±(85 ± 27) = ±58 – 112 mm  ← clear of ±135 edge
//
// VERIFIED AXLE PROFILE (caliper)
//   Base section: Ø 16.11 mm, 15 mm long
//   D-cut zone:   Ø 15.95 mm, 13 mm flat chord, 43.35 mm long
//   Tip:          3 mm
//   Total:        65.5 mm from hub face
//   Bearing seat collar: Ø 37.8 mm
// =============================================================================

$fn = 128;

// =============================================================================
// PLATE DIMENSIONS  ← primary parameters for issue #18 fix
// =============================================================================

PLATE_W     = 270.0;   // mm  width  (axle / left-right direction)
PLATE_D     = 240.0;   // mm  depth  (front-to-rear)
PLATE_THICK =   6.0;   // mm  stock thickness

// Derived
PLATE_X_HALF = PLATE_W / 2;                    // 135 mm — plate edge
FORK_DEPTH   = 50.0;                            // mm  fork slot depth (inward from edge)
AXLE_X       = PLATE_X_HALF - FORK_DEPTH;       // 85 mm — axle C/L from plate centre

// =============================================================================
// AXLE PARAMETERS — caliper-verified
// =============================================================================

AXLE_BASE_DIA   = 16.11;   AXLE_BASE_LEN  = 15.00;
AXLE_DCUT_DIA   = 15.95;   AXLE_DCUT_FLAT = 13.00;   AXLE_DCUT_LEN  = 43.35;
AXLE_TIP_LEN    =  3.00;   AXLE_TOTAL     = 65.50;
BEARING_SEAT_OD = 37.80;
TIRE_OD         = 254.0;   // 10" × 25.4 mm

// =============================================================================
// DROPOUT CLAMP PARAMETERS
// =============================================================================

FORK_W          = AXLE_BASE_DIA + 0.4;   // 16.51 mm  fork slot width

CLAMP_L         = 80.0;    // mm  clamp length along axle axis
                            //   outer end at AXLE_X + CLAMP_L/2 = 85+40 = 125 mm
                            //   plate edge at 135 mm → 10 mm margin ✓
CLAMP_H         = 60.0;    // mm  clamp height (front-to-rear, in Y)
CLAMP_THICK     =  8.0;    // mm  each clamp layer
CLAMP_BOLT_D    =  5.3;    // M5 clearance
CLAMP_BOLT_DX   = 22.0;    // mm  bolt offset ±X from axle C/L
                            //   inner bolt at AXLE_X - 22 = 63 mm ✓
                            //   outer bolt at AXLE_X + 22 = 107 mm < 135 mm ✓
CLAMP_BOLT_DY   = 22.0;    // mm  bolt offset ±Y from axle C/L
CLAMP_ALIGN_D   =  4.1;    // Ø4 alignment pin clearance

DCUT_CL         =  0.3;    // mm  D-cut bore clearance (all-round)
DCUT_R          = (AXLE_DCUT_DIA + 2*DCUT_CL) / 2;
DCUT_FC         =  AXLE_DCUT_FLAT + 2*DCUT_CL;

// =============================================================================
// STEM SOCKET
// =============================================================================

STEM_OD         = 38.1;    // mm  1.5" EMT conduit OD
STEM_BORE       = STEM_OD + 0.5;
STEM_FLANGE_OD  = 82.0;    // mm  flange ring OD
STEM_FLANGE_BC  = 66.0;    // mm  M5 bolt circle diameter (r = 33 mm)
STEM_FLANGE_T   =  6.0;    // mm  = PLATE_THICK

// Verify flange bolts clear all other holes:
//   Flange bolts at (±33, 0) and (0, ±33)
//   Clamp bolts at (±63, ±22) and (±107, ±22)
//   FC holes centred at (-40, 0) spanning X = ±55.25, Y = ±15.25
//   All separations are adequate ✓

// =============================================================================
// FC MOUNT  — MAMBA F722S 30.5 × 30.5 mm M3
// =============================================================================

FC_PITCH        = 30.5;
FC_HOLE_D       =  3.2;
FC_X_OFFSET     = -40.0;   // mm  front of plate (−X); FC at (−40, 0) within ±135 ✓

// =============================================================================
// UTILITIES
// =============================================================================

M3 = 3.2;  M4 = 4.3;  M5 = 5.3;

// =============================================================================
// RENDER CONTROL
// =============================================================================
//
//  "assembly"        full 3-D preview
//  "plate_2d"        DXF — base plate
//  "clamp_lower_2d"  DXF — lower dropout clamp  (× 2)
//  "clamp_upper_2d"  DXF — upper dropout clamp  (× 2)
//  "stem_flange_2d"  DXF — stem flange ring      (× 2)

RENDER = "assembly";

if      (RENDER == "assembly")       assembly();
else if (RENDER == "plate_2d")       projection(cut=true) translate([0,0,-PLATE_THICK/2]) base_plate();
else if (RENDER == "clamp_lower_2d") projection(cut=true) translate([0,0,-CLAMP_THICK/2]) clamp_lower();
else if (RENDER == "clamp_upper_2d") projection(cut=true) translate([0,0,-CLAMP_THICK/2]) clamp_upper();
else if (RENDER == "stem_flange_2d") projection(cut=true) translate([0,0,-STEM_FLANGE_T/2]) stem_flange();

// =============================================================================
// ASSEMBLY
// =============================================================================

module assembly() {
    color("Silver",         0.85) base_plate();

    for (side = [-1, 1]) {
        color("SteelBlue",      0.80)
            translate([side * AXLE_X, 0, PLATE_THICK])
                clamp_lower();
        color("CornflowerBlue", 0.80)
            translate([side * AXLE_X, 0, PLATE_THICK + CLAMP_THICK])
                clamp_upper();
    }

    // Stem flanges (above and below plate)
    color("DimGray", 0.70) translate([0, 0, -STEM_FLANGE_T]) stem_flange();
    color("DimGray", 0.70) translate([0, 0, PLATE_THICK])     stem_flange();

    // Ghosts — not exported
    %color("Orange", 0.25)
        translate([0, 0, PLATE_THICK + STEM_FLANGE_T])
            cylinder(d=STEM_OD, h=900);

    %for (side = [-1, 1])
        color("Tomato", 0.20)
            translate([side * PLATE_X_HALF, 0, 0])
                rotate([0, side * (-90), 0])   // axle projects inward from plate edge
                    axle_ghost();
}

// =============================================================================
// BASE PLATE  (Part A — 270 × 240 mm)
// =============================================================================

module base_plate() {
    R = 10;   // corner radius
    difference() {
        // ── Outer profile (minkowski rounded corners) ──────────────────────
        linear_extrude(PLATE_THICK)
            minkowski() {
                square([PLATE_W - 2*R, PLATE_D - 2*R], center=true);
                circle(r=R);
            }

        // ── Fork slots (open at ±X plate edges, semicircular tip) ──────────
        // Slot width FORK_W, depth FORK_DEPTH inward from plate edge.
        // Axle seats in the semicircle at X = ±(PLATE_X_HALF − FORK_DEPTH) = ±85 mm.
        for (side = [-1, 1]) {
            // Rectangular slot body
            translate([side * (PLATE_X_HALF - FORK_DEPTH), -FORK_W/2, -1])
                cube([side > 0 ? FORK_DEPTH + 1 : FORK_DEPTH + 1,
                      FORK_W, PLATE_THICK + 2]);
            // Semicircular slot tip (axle seat)
            translate([side * (PLATE_X_HALF - FORK_DEPTH), 0, -1])
                cylinder(d=FORK_W, h=PLATE_THICK + 2);
        }

        // ── Bearing seat relief (prevents Ø37.8 mm hub collar contacting edge) ─
        for (side = [-1, 1])
            translate([side * (PLATE_X_HALF - BEARING_SEAT_OD/2 - 1),
                       -BEARING_SEAT_OD/2, -1])
                cube([BEARING_SEAT_OD/2 + 2, BEARING_SEAT_OD, PLATE_THICK + 2]);

        // ── Dropout clamp bolt through-holes ───────────────────────────────
        for (side = [-1, 1])
        for (dx = [-CLAMP_BOLT_DX, CLAMP_BOLT_DX])
        for (dy = [-CLAMP_BOLT_DY, CLAMP_BOLT_DY])
            translate([side * AXLE_X + dx, dy, -1])
                cylinder(d=CLAMP_BOLT_D, h=PLATE_THICK + 2);

        // ── Alignment pin holes (Ø4 × 2 per clamp) ─────────────────────────
        for (side = [-1, 1])
        for (dy = [-CLAMP_BOLT_DY + 8, CLAMP_BOLT_DY - 8])
            translate([side * AXLE_X, dy, -1])
                cylinder(d=CLAMP_ALIGN_D, h=PLATE_THICK + 2);

        // ── Stem socket bore ─────────────────────────────────────────────────
        translate([0, 0, -1]) cylinder(d=STEM_BORE, h=PLATE_THICK + 2);

        // ── Stem flange bolt holes (4× M5 at 90° on Ø66 BC) ────────────────
        for (a = [0, 90, 180, 270])
            rotate([0, 0, a])
                translate([STEM_FLANGE_BC/2, 0, -1])
                    cylinder(d=M5, h=PLATE_THICK + 2);

        // ── FC mount holes (MAMBA F722S 30.5 × 30.5 M3) ────────────────────
        for (x = [FC_X_OFFSET - FC_PITCH/2, FC_X_OFFSET + FC_PITCH/2])
        for (y = [-FC_PITCH/2, FC_PITCH/2])
            translate([x, y, -1]) cylinder(d=FC_HOLE_D, h=PLATE_THICK + 2);

        // ── Wiring / cable pass-through slots (flanking stem) ───────────────
        // Placed at Y = ±55 mm (clear of stem flange bolts at ±33 mm and clamp at ±22 mm)
        for (dy = [-55, 55])
            hull() {
                translate([ 12, dy, -1]) cylinder(d=12, h=PLATE_THICK + 2);
                translate([-12, dy, -1]) cylinder(d=12, h=PLATE_THICK + 2);
            }

        // ── Lightening holes (2× in open areas between stem and clamp zones) ─
        // At X = 0, Y = ±80 mm (front/rear open corridor)
        for (dy = [-80, 80])
            hull() {
                translate([ 20, dy, -1]) cylinder(d=20, h=PLATE_THICK + 2);
                translate([-20, dy, -1]) cylinder(d=20, h=PLATE_THICK + 2);
            }
    }
}

// =============================================================================
// STEM FLANGE RING  (laser-cut, qty 2)
// =============================================================================

module stem_flange() {
    difference() {
        cylinder(d=STEM_FLANGE_OD, h=STEM_FLANGE_T);
        translate([0, 0, -1]) cylinder(d=STEM_BORE, h=STEM_FLANGE_T + 2);
        for (a = [0, 90, 180, 270])
            rotate([0, 0, a])
                translate([STEM_FLANGE_BC/2, 0, -1])
                    cylinder(d=M5, h=STEM_FLANGE_T + 2);
    }
}

// =============================================================================
// DROPOUT CLAMP — LOWER  (round bore, base section)
// =============================================================================

module clamp_lower() {
    difference() {
        hull() {
            translate([-CLAMP_L/2 + CLAMP_H/2, 0, 0]) cylinder(d=CLAMP_H, h=CLAMP_THICK);
            translate([ CLAMP_L/2 - CLAMP_H/2, 0, 0]) cylinder(d=CLAMP_H, h=CLAMP_THICK);
        }
        translate([0,0,-1]) cylinder(d=AXLE_BASE_DIA + 0.4, h=CLAMP_THICK + 2);
        // Open entry slot (axle slides in from plate edge)
        translate([-CLAMP_L/2 - 1, -FORK_W/2, -1])
            cube([CLAMP_L/2 + 1, FORK_W, CLAMP_THICK + 2]);
        for (dx = [-CLAMP_BOLT_DX, CLAMP_BOLT_DX])
        for (dy = [-CLAMP_BOLT_DY, CLAMP_BOLT_DY])
            translate([dx, dy, -1]) cylinder(d=CLAMP_BOLT_D, h=CLAMP_THICK + 2);
        for (dy = [-CLAMP_BOLT_DY + 8, CLAMP_BOLT_DY - 8])
            translate([0, dy, -1]) cylinder(d=CLAMP_ALIGN_D, h=CLAMP_THICK + 2);
    }
}

// =============================================================================
// DROPOUT CLAMP — UPPER  (D-cut bore, anti-rotation)
// =============================================================================

module clamp_upper() {
    dcut_d = sqrt(pow(DCUT_R, 2) - pow(DCUT_FC/2, 2));
    difference() {
        hull() {
            translate([-CLAMP_L/2 + CLAMP_H/2, 0, 0]) cylinder(d=CLAMP_H, h=CLAMP_THICK);
            translate([ CLAMP_L/2 - CLAMP_H/2, 0, 0]) cylinder(d=CLAMP_H, h=CLAMP_THICK);
        }
        translate([0,0,-1])
            linear_extrude(CLAMP_THICK + 2) dcut_profile_2d(DCUT_R, dcut_d);
        translate([-CLAMP_L/2 - 1, -FORK_W/2, -1])
            cube([CLAMP_L/2 + 1, FORK_W, CLAMP_THICK + 2]);
        for (dx = [-CLAMP_BOLT_DX, CLAMP_BOLT_DX])
        for (dy = [-CLAMP_BOLT_DY, CLAMP_BOLT_DY])
            translate([dx, dy, -1]) cylinder(d=CLAMP_BOLT_D, h=CLAMP_THICK + 2);
        for (dy = [-CLAMP_BOLT_DY + 8, CLAMP_BOLT_DY - 8])
            translate([0, dy, -1]) cylinder(d=CLAMP_ALIGN_D, h=CLAMP_THICK + 2);
        // Orientation marker (triangle pointing toward flat)
        translate([0, dcut_d + 1.5, CLAMP_THICK - 0.8])
            linear_extrude(1) polygon([[0,0],[-3,-5],[3,-5]]);
    }
}

module dcut_profile_2d(r, flat_d) {
    intersection() {
        circle(r=r);
        translate([-r-1, -r-1]) square([2*(r+1), r+1+flat_d]);
    }
}

// =============================================================================
// AXLE GHOST  (visualisation only)
// =============================================================================

module axle_ghost() {
    cylinder(d=BEARING_SEAT_OD, h=12);
    translate([0,0,12])                cylinder(d=AXLE_BASE_DIA,  h=AXLE_BASE_LEN);
    translate([0,0,12+AXLE_BASE_LEN]) cylinder(d=AXLE_DCUT_DIA, h=AXLE_DCUT_LEN);
}

// =============================================================================
// DXF EXPORT COMMANDS
// =============================================================================
//
//  Base plate (270 × 240 mm, 6 mm Al or 8 mm acrylic):
//    openscad prototype_baseplate.scad -D 'RENDER="plate_2d"' -o baseplate.dxf
//
//  Dropout clamp lower (× 2):
//    openscad prototype_baseplate.scad -D 'RENDER="clamp_lower_2d"' -o clamp_lower.dxf
//
//  Dropout clamp upper (× 2):
//    openscad prototype_baseplate.scad -D 'RENDER="clamp_upper_2d"' -o clamp_upper.dxf
//
//  Stem flange ring (× 2):
//    openscad prototype_baseplate.scad -D 'RENDER="stem_flange_2d"' -o stem_flange.dxf
//
//  PLATE BLANK:   280 × 250 mm  (10 mm oversized each side for datum + clamping)
//  CLAMP BLANKS:  90 × 70 mm each
//  FLANGE BLANKS: Ø90 mm disc each
// =============================================================================