bare/qwen3-0.6b / tier-3-butt-hinge

```openscad
// OpenSCAD butt hinge design: left plate, right plate, and pivot pin

// Define base plates (left and right)
part left_plate = cylinder(
    dimensions => [30, 25, 2],
    radius => 1.5,
    height => 2,
    y => 30,
    x => -0.5,
    z => 0
);

part right_plate = cylinder(
    dimensions => [30, 25, 2],
    radius => 1.5,
    height => 2,
    y => 6,
    x => 0.5,
    z => 0
);

// Define pivot pin (cylinder)
pin_cylinders = cylinder(
    dimensions => [32, 4, 0.1],
    radius => 2,
    height => 32,
    center_y => 0.5
);

// Knuckles for left and right plates
left_knuckles = [
    pin_cylinders,
    pin_cylinders,
    pin_cylinders,
    pin_cylinders
];

right_knuckles = [
    pin_cylinders,
    pin_cylinders
];

// Holes in knuckles (M3 nuts)
holes_left = [
    cylinder(
        dimensions => [8, 6, 1.5],
        radius => 3.2,
        z => -0.5
    ),
    cylinder(
        dimensions => [8, 6, 1.5],
        radius => 4.6,
        z => 0.5
    )
];

holes_right = [
    cylinder(
        dimensions => [8, 6, 1.5],
        radius => 3.2,
        z => -0.5
    ),
    cylinder(
        dimensions => [8, 6, 1.5],
        radius => 4.6,
        z => 0.5
    )
];

// Coordinate system setup
set_coords() {
    pivot_y = 32mm;
    left_x = -0.5;
    right_x = 0.5;
    knuckle_center_y = 6mm;
}

// Combine all components into one file with correct positions and connections
file "butt_hinge.scad" {
    // Left plate at x <0, right at x >0
    left_plate + right_plate + pin_cylinders + holes_left + holes_right
}
```