opel-cad/opel_pin.py

from build123d import *
from ocp_vscode import show

# ==========================================
# --- MASTER PARAMETERS ---
model_size = 31.0  # Outer diameter of the ring
overhang = model_size * (3.0 / 31.0)     # How many mm the bolt sticks out
# ==========================================

# --- Derived Parameters ---
outer_diameter = model_size
inner_diameter = model_size * (25.4 / 31.0)
thickness      = model_size * (2.3 / 31.0)

pin_diameter   = model_size * (3.1 / 31.0)
pin_length     = model_size * (10.8 / 31.0)
pin_spacing    = model_size * (14.0 / 31.0)
pin_height_offset = model_size * (1.55 / 31.0)
fillet_radius  = model_size * (0.15 / 31.0)

# --- Stud Parameters ---
stud_stickout  = model_size * (0.4 / 31.0)
stud_thickness = model_size * (0.5 / 31.0)

# --- Lightning Bolt Proportions ---
W = (outer_diameter / 2) + overhang
bound = model_size 
H_outer = model_size * (3.1 / 31.0) 
H_inner = model_size * (0.5 / 31.0)
X_point = model_size * (5.8 / 31.0)
X_inner = model_size * (2.7 / 31.0)

# ==========================================
# --- 1. BUILD THE MASTER PIN ---
# We build a single fully-studded pin first.
with BuildPart() as master_pin:
    # Build the smooth base cylinder
    Cylinder(radius=pin_diameter / 2, height=pin_length)
    
    # We will place 3 rows of studs vertically along the pin
    # We use 0.25 and -0.25 so the studs sit neatly along the middle shaft
    z_offsets = [pin_length * 0.25, 0, -pin_length * 0.25]
    
    for z in z_offsets:
        with Locations((0, 0, z)):
            # PolarLocations places local coordinate systems around a circle.
            # It naturally rotates so the local "X" axis points directly outward!
            with PolarLocations(radius=pin_diameter / 2, count=4):
                # A box is drawn. Since we want it sticking out by "stud_stickout",
                # we make its length exactly double that (half embeds into the pin, half sticks out)
                Box(length=stud_stickout * 2, width=stud_thickness, height=stud_thickness)
# ==========================================


# ==========================================
# --- 2. BUILD THE OPEL LOGO ---
with BuildPart() as opel_pin:
    # 1. Base Ring
    with BuildSketch() as ring_sketch:
        Circle(outer_diameter / 2)
        Circle(inner_diameter / 2, mode=Mode.SUBTRACT)
    extrude(amount=thickness)

    # 2. Lightning Bolt Profile (Aggressive Z-Shape)
    with BuildSketch() as bolt_sketch:
        pts = [
            (-bound, H_outer),           
            (-bound, -H_inner),          
            (-X_inner, -H_inner),        
            (-X_point, -H_outer),        
            (bound, -H_outer),           
            (bound, H_inner),            
            (X_inner, H_inner),          
            (X_point, H_outer)           
        ]
        z_shape = Polygon(*pts)
        fillet(z_shape.vertices(), radius=fillet_radius)
        Circle(W, mode=Mode.INTERSECT)
    extrude(amount=thickness)

    # 3. Fillet ALL top edges
    top_face = opel_pin.faces().sort_by(Axis.Z)[-1]
    fillet(top_face.edges(), radius=fillet_radius)

    # 4. Attach the Studded Mounting Pins
    # Because the logo extrudes upwards from Z=0, the back is perfectly flat at Z=0.
    # We place our master_pin so its top (pin_length / 2) sits flush against the back.
    with Locations((-pin_spacing, pin_height_offset, -pin_length / 2), 
                   (pin_spacing, -pin_height_offset, -pin_length / 2)):
        add(master_pin.part)
# ==========================================

# --- Export for 3D Printing ---
export_step(opel_pin.part, "vintage_opel_pin.step")

# --- Send to OCP CAD Viewer ---
show(opel_pin)