Import CAD projects and cad-router v1

2026-07-22 19:38:36 +08:00
parent e4e0199bd5
commit af9f630c11
2253 changed files with 1994207 additions and 0 deletions
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+from math import asin, cos, hypot, radians, sin, tau
+
+from build123d import (
+    Align,
+    BuildPart,
+    BuildSketch,
+    Color,
+    Cylinder,
+    Location,
+    Locations,
+    Mode,
+    Plane,
+    Polygon,
+    add,
+    extrude,
+    fillet,
+)
+
+
+# Units: millimeters.
+# Origin: impeller axis centered at X=0, Y=0.
+# XY: backplate plane. +Z: vertical impeller axis.
+# Assumed rotation direction: counter-clockwise viewed from +Z, so blade tips
+# trail clockwise by the specified backward sweep.
+
+BACKPLATE_DIAMETER = 90.0
+BACKPLATE_RADIUS = BACKPLATE_DIAMETER / 2.0
+BACKPLATE_THICKNESS = 6.0
+BACKPLATE_OUTER_FILLET_RADIUS = 1.5
+
+HUB_DIAMETER = 26.0
+HUB_RADIUS = HUB_DIAMETER / 2.0
+HUB_HEIGHT_ABOVE_BACKPLATE = 22.0
+
+BORE_DIAMETER = 8.0
+BORE_RADIUS = BORE_DIAMETER / 2.0
+
+BLADE_COUNT = 12
+BLADE_ROOT_RADIUS = 18.0
+BLADE_TIP_RADIUS = 43.0
+BLADE_THICKNESS = 3.0
+BLADE_HEIGHT_ABOVE_BACKPLATE = 16.0
+BLADE_BACKWARD_SWEEP_ANGLE = radians(45.0)
+BLADE_CURVE_SEGMENTS = 5
+BLADE_ROOT_FILLET_RADIUS = 1.0
+BLADE_ROOT_FILLET_MAX_RADIUS = 30.0
+
+MODEL_LABEL = "centrifugal_impeller_12_backward_curved_blades"
+
+
+def _polar_point(radius: float, angle: float) -> tuple[float, float]:
+    return (radius * cos(angle), radius * sin(angle))
+
+
+def _clamp_radius(point: tuple[float, float]) -> tuple[float, float]:
+    x_pos, y_pos = point
+    radius = hypot(x_pos, y_pos)
+
+    if radius < BLADE_ROOT_RADIUS:
+        scale = BLADE_ROOT_RADIUS / radius
+        return (x_pos * scale, y_pos * scale)
+    if radius > BLADE_TIP_RADIUS:
+        scale = BLADE_TIP_RADIUS / radius
+        return (x_pos * scale, y_pos * scale)
+    return point
+
+
+def _blade_center_point(base_angle: float, t: float) -> tuple[float, float]:
+    radius = BLADE_ROOT_RADIUS + (BLADE_TIP_RADIUS - BLADE_ROOT_RADIUS) * t
+    angle = base_angle - BLADE_BACKWARD_SWEEP_ANGLE * t
+    return _polar_point(radius, angle)
+
+
+def _blade_normal(base_angle: float, t: float) -> tuple[float, float]:
+    radius = BLADE_ROOT_RADIUS + (BLADE_TIP_RADIUS - BLADE_ROOT_RADIUS) * t
+    dr_dt = BLADE_TIP_RADIUS - BLADE_ROOT_RADIUS
+    dtheta_dt = -BLADE_BACKWARD_SWEEP_ANGLE
+    angle = base_angle + dtheta_dt * t
+
+    dx_dt = dr_dt * cos(angle) - radius * sin(angle) * dtheta_dt
+    dy_dt = dr_dt * sin(angle) + radius * cos(angle) * dtheta_dt
+    length = hypot(dx_dt, dy_dt)
+    return (-dy_dt / length, dx_dt / length)
+
+
+def _blade_endpoint_points(base_angle: float, t: float) -> tuple[tuple[float, float], tuple[float, float]]:
+    radius = BLADE_ROOT_RADIUS if t == 0.0 else BLADE_TIP_RADIUS
+    angle = base_angle - BLADE_BACKWARD_SWEEP_ANGLE * t
+    half_angle = asin((BLADE_THICKNESS / 2.0) / radius)
+    return (
+        _polar_point(radius, angle + half_angle),
+        _polar_point(radius, angle - half_angle),
+    )
+
+
+def _blade_outline(base_angle: float) -> list[tuple[float, float]]:
+    left_side: list[tuple[float, float]] = []
+    right_side: list[tuple[float, float]] = []
+    half_thickness = BLADE_THICKNESS / 2.0
+
+    for index in range(BLADE_CURVE_SEGMENTS + 1):
+        t = index / BLADE_CURVE_SEGMENTS
+        if index == 0 or index == BLADE_CURVE_SEGMENTS:
+            left_point, right_point = _blade_endpoint_points(base_angle, t)
+            left_side.append(left_point)
+            right_side.append(right_point)
+            continue
+
+        x_pos, y_pos = _blade_center_point(base_angle, t)
+        nx, ny = _blade_normal(base_angle, t)
+        left_side.append(
+            _clamp_radius((x_pos + nx * half_thickness, y_pos + ny * half_thickness))
+        )
+        right_side.append(
+            _clamp_radius((x_pos - nx * half_thickness, y_pos - ny * half_thickness))
+        )
+
+    return left_side + list(reversed(right_side))
+
+
+def _make_blade(index: int):
+    base_angle = tau * index / BLADE_COUNT
+
+    with BuildPart() as blade:
+        with BuildSketch(Plane.XY):
+            Polygon(_blade_outline(base_angle), align=None)
+        extrude(amount=BLADE_HEIGHT_ABOVE_BACKPLATE)
+
+    part = blade.part.moved(Location((0.0, 0.0, BACKPLATE_THICKNESS)))
+    part.label = f"blade_{index + 1:02d}"
+    return part
+
+
+def _make_backplate():
+    with BuildPart() as backplate:
+        Cylinder(
+            radius=BACKPLATE_RADIUS,
+            height=BACKPLATE_THICKNESS,
+            align=(Align.CENTER, Align.CENTER, Align.MIN),
+        )
+
+    part = backplate.part
+    outer_edges = []
+    outer_edges.extend(_edges_near_z_radius(part, 0.0, BACKPLATE_RADIUS))
+    outer_edges.extend(_edges_near_z_radius(part, BACKPLATE_THICKNESS, BACKPLATE_RADIUS))
+    part = fillet(outer_edges, radius=BACKPLATE_OUTER_FILLET_RADIUS)
+    part.label = "filleted_backplate"
+    return part
+
+
+def _edge_z(edge) -> float:
+    return edge.bounding_box().center().Z
+
+
+def _edge_xy_radius(edge) -> float:
+    center = edge.bounding_box().center()
+    return hypot(center.X, center.Y)
+
+
+def _circle_radius(edge) -> float | None:
+    try:
+        return edge.radius
+    except ValueError:
+        return None
+
+
+def _edges_near_z_radius(part, z_value: float, radius: float, tolerance: float = 0.02):
+    edges = []
+    for edge in part.edges():
+        circle_radius = _circle_radius(edge)
+        if circle_radius is None:
+            continue
+        if abs(_edge_z(edge) - z_value) <= tolerance and abs(circle_radius - radius) <= tolerance:
+            edges.append(edge)
+    return edges
+
+
+def _blade_root_edges(part):
+    min_radius = BLADE_ROOT_RADIUS - BLADE_THICKNESS
+    edges = []
+
+    for edge in part.edges():
+        if _circle_radius(edge) is not None:
+            continue
+        if abs(_edge_z(edge) - BACKPLATE_THICKNESS) > 0.02:
+            continue
+        if min_radius <= _edge_xy_radius(edge) <= BLADE_ROOT_FILLET_MAX_RADIUS:
+            edges.append(edge)
+
+    return edges
+
+
+def gen_step():
+    """Return a single solid centrifugal impeller in millimeters."""
+    total_height = BACKPLATE_THICKNESS + HUB_HEIGHT_ABOVE_BACKPLATE
+    backplate = _make_backplate()
+
+    with BuildPart() as impeller:
+        add(backplate, mode=Mode.ADD)
+
+        with Locations(Location((0.0, 0.0, BACKPLATE_THICKNESS))):
+            Cylinder(
+                radius=HUB_RADIUS,
+                height=HUB_HEIGHT_ABOVE_BACKPLATE,
+                align=(Align.CENTER, Align.CENTER, Align.MIN),
+                mode=Mode.ADD,
+            )
+
+        for blade_index in range(BLADE_COUNT):
+            add(_make_blade(blade_index), mode=Mode.ADD)
+
+        with Locations(Location((0.0, 0.0, -1.0))):
+            Cylinder(
+                radius=BORE_RADIUS,
+                height=total_height + 2.0,
+                align=(Align.CENTER, Align.CENTER, Align.MIN),
+                mode=Mode.SUBTRACT,
+            )
+
+    part = impeller.part
+
+    root_edges = _blade_root_edges(part)
+    root_edges.extend(_edges_near_z_radius(part, BACKPLATE_THICKNESS, HUB_RADIUS))
+    if root_edges:
+        part = fillet(root_edges, radius=BLADE_ROOT_FILLET_RADIUS)
+
+    part.label = MODEL_LABEL
+    part.color = Color(0.62, 0.66, 0.70, 1.0)
+    return part