// MB-001 — REMOTE pan-tilt stereo camera rig (concept CAD, parametric)
// Rig only: base (1/4"-20 tripod hole / desk), pan servo, tilt yoke, stereo camera bar,
// ghost servo-controller + Pi 5. Nothing is mounted on the headset.
// Units: mm. Z up. Pan axis = Z through origin. Tilt axis = X. Cameras look toward +Y.
// Render a printable part:  openscad -D 'part="base"' -o base.stl mb001_rig.scad
//   part = "assembly" | "base" | "yoke" | "cam_bar"
//
// SERVO NUMBERS: L,W,H from vendor pages (see research/MB-001-servos-power.md).
//   shaft_off (shaft position from the body end) and spline height are APPROXIMATE
//   concept values, NOT sourced -> check against vendor STEP/drawing before printing.
// CAMERA NUMBERS: Brio 102 x 27 x 26.5 mm (Logitech datasheet). 38 mm module depth is NOT
//   sourced (assumed 15 mm incl. lens) -> measure the Quanrui USB48MP01-QFZ.

part         = "assembly";
cam_type     = "module38";   // "module38" | "brio"
servo_type   = "sts3215";    // "mg90s" | "sh0257" | "mg996r" | "ds3218" | "sts3215"
cam_spacing  = 63;           // centre-to-centre, mm. AVP IPD range 51..75 mm
show_ghosts  = true;         // servos, cameras, Pi, PCA9685 in assembly view
pan_deg      = 0;            // pose preview
tilt_deg     = 0;
tripod_hole  = 6.6;          // 1/4"-20 clearance (6.35 nominal)
use_nut_trap = true;

$fn = 48;

// ---------- servo table: [L, W, H, shaft_off(approx), flange_w, horn_d] ----------
function servo_dims(t) =
  t=="mg90s"   ? [22.8, 12.2, 28.5,  5.5, 32.5, 20] :
  t=="sh0257"  ? [22.8, 12.0, 25.4,  5.5, 32.5, 20] :
  t=="mg996r"  ? [40.7, 19.7, 42.9, 10.0, 53.0, 25] :
  t=="ds3218"  ? [40.0, 20.0, 40.5, 10.0, 54.0, 25] :
  /*sts3215*/    [45.2, 24.7, 35.0, 10.0, 45.2, 25];
function sv_L(t)=servo_dims(t)[0];  function sv_W(t)=servo_dims(t)[1];
function sv_H(t)=servo_dims(t)[2];  function sv_so(t)=servo_dims(t)[3];
function sv_horn(t)=servo_dims(t)[5];

// ---------- camera table: [w, h, depth] as mounted (portrait Brio so 63 mm spacing fits) ----------
module38_dims = [38, 38, 15];
brio_dims     = [27, 102, 26.5];           // Brio rotated 90 deg: 102 mm tall, 27 wide
function cam_dims() = cam_type=="brio" ? brio_dims : module38_dims;
cw = cam_dims()[0]; ch = cam_dims()[1]; cd = cam_dims()[2];

// ---------- derived geometry ----------
sL = sv_L(servo_type); sW = sv_W(servo_type); sH = sv_H(servo_type); so = sv_so(servo_type);
hd = sv_horn(servo_type);
wall  = 2.4;  base_t = 6;
deck_x = 100; deck_y0 = -112; deck_y1 = 46;  // deck: x +-50, y -112..46
horn_t = 3;   yoke_t = 4; arm_t = 4; bar_t = 4; gap = 1.0;
bar_len = cam_spacing + cw + 2*10;           // camera bar length along X
bar_h   = ch + 14;
// pan servo: shaft at origin, body toward +X
z_s   = base_t + sH - 4;                      // spline tip height (body bottom on deck)
z_y   = z_s + horn_t + 1;                     // top of horn / underside of yoke plate
arm_x = bar_len/2 + gap + arm_t/2;            // arm centre-plane
tilt_z = z_y + yoke_t + bar_h/2 + 6;          // tilt axis height
yoke_w = 2*arm_x + arm_t;

// ---------- primitives ----------
module servo_body(t) {            // shaft at origin pointing +Z, body below
  L=sv_L(t); W=sv_W(t); H=sv_H(t); s=sv_so(t); fw=servo_dims(t)[4];
  color("#444") translate([-s, -W/2, -H+4]) cube([L, W, H-8]);       // body
  color("#444") translate([-(fw-L)/2 - s, -W/2, -H+4+ (H-8)*0.62]) cube([fw, W, 2.5]); // flange
  color("#999") cylinder(d=6, h=6);                                   // spline
}
module horn(d, t) { color("#ddd") cylinder(d=d, h=t); }

module camera() {                 // origin at lens centre on rear face; looks +Y
  color("#222") translate([-cw/2, 0, -ch/2]) cube([cw, cd, ch]);
  color("#68c") translate([0, cd, 0]) rotate([-90,0,0]) cylinder(d=min(cw,ch)*0.45, h=3);
}
module m3_hole(h=40, d=3.3) cylinder(d=d, h=h, center=true, $fn=24);

// ---------- BASE ----------
module base() {
  difference() {
    union() {
      translate([-deck_x/2, deck_y0, 0]) cube([deck_x, deck_y1-deck_y0, base_t]);
      // pan-servo cradle walls (servo body toward +X, shaft at origin)
      translate([-so-wall, -sW/2-wall, base_t])
        difference() {
          cube([sL+2*wall, sW+2*wall, sH*0.55]);
          translate([wall, wall, -1]) cube([sL, sW, sH]);
        }
    }
    // 1/4"-20 tripod hole, centred on pan axis, with nut trap underneath
    translate([0,0,-1]) cylinder(d=tripod_hole, h=base_t+2);
    if (use_nut_trap) translate([0,0,-0.01]) cylinder(d=12.0, h=2.5, $fn=6);  // trap: ~11 mm A/F nut (check)
    // desk screw slots
    for (sx=[-1,1], y=[deck_y0+8, deck_y1-8]) translate([sx*(deck_x/2-8), y, 0]) m3_hole(base_t*3, 4.2);
    // Pi 5 standoff holes (58 x 49 pattern per Raspberry Pi mechanical drawing), centred on deck at y=-70
    for (dx=[-29,29], dy=[-24.5,24.5]) translate([dx, -70+dy, 0]) m3_hole(base_t*3, 2.7);
    // servo cable slot
    translate([-so+2, -sW/2, -1]) cube([6, sW, base_t+2]);
  }
}

// ---------- YOKE (pan platform + two arms, tilt servo on +X arm) ----------
module yoke() {
  difference() {
    union() {
      // pan plate (bolts to pan horn)
      translate([-yoke_w/2, -22, z_y]) cube([yoke_w, 44, yoke_t]);
      // arms
      for (sx=[-1,1]) translate([sx*arm_x - arm_t/2, -16, z_y])
        cube([arm_t, 32, tilt_z - z_y + 14]);
    }
    // horn screw pattern (4x on r=8)
    for (a=[0:90:270]) translate([8*cos(a), 8*sin(a), z_y]) m3_hole(3*yoke_t, 2.6);
    // centre hole
    translate([0,0,z_y-1]) cylinder(d=7, h=yoke_t+2);
    // tilt pivot holes (x-axis): bearing/bolt side (-X) and servo spline side (+X)
    translate([0,0,tilt_z]) rotate([0,90,0]) cylinder(d=8.2, h=3*yoke_w, center=true);
  }
  // servo seat on +X arm outer face (servo body outward, shaft pointing -X)
  if (part!="assembly") translate([arm_x+arm_t/2, 0, tilt_z]) rotate([0,-90,0]) %servo_body(servo_type);
}

// ---------- CAMERA BAR (tilts about X axis through its centre) ----------
module cam_bar() {
  difference() {
    translate([-bar_len/2, -bar_t/2, -bar_h/2]) cube([bar_len, bar_t, bar_h]);
    // cable / lens relief windows
    for (sx=[-1,1]) translate([sx*cam_spacing/2, 0, 0])
      cube([cw*0.5, 3*bar_t, ch*0.5], center=true);
    // centre axle hole for tilt pin (also horn screws on the servo end)
    rotate([0,90,0]) cylinder(d=3.3, h=bar_len+2, center=true, $fn=24);
    // M3 mounting holes at each camera (4 per camera at +-(cw/2-3), +-(min(ch,40)/2-3))
    for (sx=[-1,1], hx=[-1,1], hz=[-1,1])
      translate([sx*cam_spacing/2 + hx*(cw/2-3.5), 0, hz*(min(ch,38)/2-3.5)]) rotate([90,0,0]) m3_hole(3*bar_t, 2.9);
  }
  // end hubs that clamp onto the horn / bearing pin
  for (sx=[-1,1]) translate([sx*(bar_len/2), 0, 0]) rotate([0,90,0]) cylinder(d=14, h=2, center=true);
}

// ---------- GHOSTS (pose + non-printed parts) ----------
module ghosts() {
  // pan servo
  translate([0,0,z_s]) servo_body(servo_type);
  // horn
  translate([0,0,z_s+1]) horn(hd, horn_t);
  // Raspberry Pi 5 (85 x 56 mm board, ~20 mm tall with USB) on deck, y centre -70
  color("#2a7", 0.35) translate([-28, -70-42.5, base_t+5]) cube([56, 85, 17]);
  // PCA9685 (approx 62 x 25 x 8) beside the Pi — approximate, unsourced size
  color("#d62", 0.45) translate([-31, -104, base_t+1]) cube([62, 14, 8]);
  // power: servo UBEC / bus adapter placeholder
  color("#c33", 0.4) translate([32, -60, base_t+1]) cube([14, 30, 10]);
}
module tilt_assembly() {
  translate([0,0,tilt_z]) rotate([tilt_deg,0,0]) {
    cam_bar();
    if (show_ghosts) for (sx=[-1,1]) translate([sx*cam_spacing/2, bar_t/2, 0]) camera();
  }
  if (show_ghosts) translate([arm_x+arm_t/2, 0, tilt_z]) rotate([0,-90,0]) servo_body(servo_type);
}

module assembly() {
  color("#b8c4d0") base();
  rotate([0,0,pan_deg]) {
    color("#d9a05b") yoke();
    tilt_assembly();
  }
  if (show_ghosts) ghosts();
}

if (part=="assembly") assembly();
else if (part=="base") base();
else if (part=="yoke") yoke();
else if (part=="cam_bar") rotate([90,0,0]) cam_bar();   // lay flat for printing

// echo key numbers
echo(str("bar_len=",bar_len," bar_h=",bar_h," tilt_z=",tilt_z," yoke_w=",yoke_w,
         " cam=",cam_type," servo=",servo_type," spacing=",cam_spacing));