Light Diffuser for the Lamp of My Kid

#!/home/sam/.local/pipx/venvs/clk/bin/python

from build123d import *


# --- Parameters ---
cylinder_diameter = 80  # 8cm cylinder diameter
cylinder_radius = cylinder_diameter / 2
edge_thickness = 2  # 2mm edge thickness of the cylinder
clip_depth = 10  # depth the clip slides onto the cylinder
diffuser_thickness = 1.5  # thickness of the diffuser dome shell
dome_height = 25  # height of the dome bulge

# Derived dimensions
# The 8cm diameter is the circle formed by the gap between walls.
# The gap (= edge_thickness) is centered on cylinder_radius.
inner_wall_outer_radius = cylinder_radius - edge_thickness / 2
outer_wall_inner_radius = cylinder_radius + edge_thickness / 2
wall_thickness = 1.2  # thickness of each clip wall
diffuser_radius = (
    outer_wall_inner_radius + wall_thickness + 5
)  # disk extends beyond clip

with BuildPart() as diffuser:
    # --- Dome diffuser (bulgy shell, sitting on build plate) ---
    # Outer dome
    with BuildSketch(Plane.XZ):
        with BuildLine():
            Line((0, 0), (diffuser_radius, 0))
            EllipticalCenterArc((0, 0), diffuser_radius, dome_height, 0, 90)
            Line((0, dome_height), (0, 0))
        make_face()
    revolve(axis=Axis.Z)
    # Hollow out the dome, keeping a closed shell of diffuser_thickness
    # Profile in XZ plane: the ellipse center is shifted up by diffuser_thickness
    # so the cavity doesn't reach Z=0, leaving a solid base
    with BuildSketch(Plane.XZ):
        with BuildLine():
            dt = diffuser_thickness
            Line((0, dt), (diffuser_radius - dt, dt))
            EllipticalCenterArc(
                (0, dt),
                diffuser_radius - dt,
                dome_height - dt,
                0,
                90,
            )
            Line((0, dome_height), (0, dt))
        make_face()
    revolve(axis=Axis.Z, mode=Mode.SUBTRACT)

    # --- Inner clip wall (grows upward from dome base) ---
    Cylinder(
        radius=inner_wall_outer_radius,
        height=dome_height + clip_depth,
        align=(Align.CENTER, Align.CENTER, Align.MIN),
    )
    Cylinder(
        radius=inner_wall_outer_radius - wall_thickness,
        height=dome_height + clip_depth,
        align=(Align.CENTER, Align.CENTER, Align.MIN),
        mode=Mode.SUBTRACT,
    )

    # --- Outer clip wall (grows upward from dome base) ---
    Cylinder(
        radius=outer_wall_inner_radius + wall_thickness,
        height=dome_height + clip_depth,
        align=(Align.CENTER, Align.CENTER, Align.MIN),
    )
    Cylinder(
        radius=outer_wall_inner_radius,
        height=dome_height + clip_depth,
        align=(Align.CENTER, Align.CENTER, Align.MIN),
        mode=Mode.SUBTRACT,
    )

export_stl(diffuser.part, "test.stl")