// NEMA 17 sheet-metal L mount (2 mm steel)
// Z up, part rests on Z=0. Base in XY (X = width, Y = depth, front at Y=0),
// upright rises at the back (outer face at Y = base_depth).
// Dimensions are OUTSIDE (mold-line) sizes: base 50x40, upright 50x50.

/* [Mode] */
mode = "folded"; // [folded, flat, flat3d]

/* [Sheet] */
thickness = 2;        // [0.5:0.1:6]
bend_radius = 2;      // inside bend radius [0.5:0.1:10]
k_factor = 0.44;      // [0.2:0.01:0.5]

/* [Size] */
width = 50;           // [30:1:100]
base_depth = 40;      // outside depth of base [20:1:100]
upright_height = 50;  // outside height of upright [30:1:100]

/* [Motor face (NEMA 17)] */
bore_d = 22.5;        // [10:0.1:30]
screw_d = 3.4;        // [2:0.1:6]
screw_pitch = 31;     // [20:0.1:50]
motor_center_z = 25;  // height of bore centre from Z=0 (face centre) [15:0.5:60]

/* [Base slots] */
slot_w = 5.5;         // [3:0.1:10]
slot_len = 12;        // overall slot length incl. round ends [6:0.5:30]
slot_spacing = 30;    // X distance between slot centres [10:1:90]
slot_center_y = 18;   // slot centre from front edge [6:0.5:40]

/* [Hidden] */
$fn = 96;
T = thickness; R = bend_radius;
bend_ang = 90;
BA = PI/2 * (R + k_factor*T);          // bend allowance, 90 deg
base_flat = base_depth - (R + T);       // straight base length
up_flat = upright_height - (R + T);     // straight upright length
flat_len = base_flat + BA + up_flat;
echo(BA=BA, base_flat=base_flat, up_flat=up_flat, flat_len=flat_len, flat_w=width);

module slot2d(l, w) {
    hull() for (s = [-1, 1]) translate([0, s*(l - w)/2]) circle(d = w);
}
module face_holes2d() {          // centred on (0,0)
    circle(d = bore_d);
    for (sx = [-1, 1], sy = [-1, 1]) translate([sx, sy]*screw_pitch/2) circle(d = screw_d);
}
module base_holes2d() {
    for (sx = [-1, 1]) translate([width/2 + sx*slot_spacing/2, slot_center_y]) slot2d(slot_len, slot_w);
}

// ---------- folded ----------
module folded() {
    // base
    difference() {
        cube([width, base_flat, T]);
        translate([0, 0, -1]) linear_extrude(T + 2) base_holes2d();
    }
    // bend: axis along X at (y = base_flat, z = R + T)
    translate([0, base_flat, R + T])
        multmatrix([[0,0,1,0],[0,1,0,0],[-1,0,0,0],[0,0,0,1]])
            rotate_extrude(angle = bend_ang, $fn = 128)
                translate([R, 0]) square([T, width]);
    // upright
    difference() {
        translate([0, base_flat + R, R + T]) cube([width, T, up_flat]);
        translate([width/2, base_flat + R - 1, motor_center_z])
            rotate([-90, 0, 0]) linear_extrude(T + 2) face_holes2d();
    }
}

// ---------- flat pattern (2D, XY) ----------
// Y = 0 at base front edge, upright free edge at Y = flat_len.
module flat2d() {
    difference() {
        square([width, flat_len]);
        base_holes2d();
        translate([width/2, base_flat + BA + (motor_center_z - (R + T))]) face_holes2d();
    }
}

if (mode == "folded") folded();
else if (mode == "flat") flat2d();
else linear_extrude(T) flat2d();