Split project into frontend and backend

2026-08-13 16:24:36 +08:00
commit f051146486
274 changed files with 953932 additions and 0 deletions
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+from dataclasses import dataclass
+from pathlib import Path
+import math
+
+import cadquery as cq
+
+
+# All dimensions are millimetres.  The main body is a revolved radial section.
+INNER_BOTTOM_RADIUS = 60.0
+INNER_STEP_RADIUS = 57.5
+INNER_SHOULDER_RADIUS = 70.0
+INNER_WALL_RADIUS = 79.0
+BOTTOM_OUTER_RADIUS = 77.5
+BODY_OUTER_RADIUS = 82.5
+TOP_OUTER_RADIUS = 85.0
+BASE_MIN_Z = -18.0
+BASE_MAX_Z = 92.0
+BASE_HEIGHT = BASE_MAX_Z - BASE_MIN_Z
+
+
+@dataclass(frozen=True)
+class HousingScale:
+    radial_scale: float = 1.0
+    axial_scale: float = 1.0
+    source: str = "default_template_scale"
+
+
+def scaled_dimensions(scale: HousingScale) -> dict[str, float]:
+    return {
+        "inner_bottom_radius": INNER_BOTTOM_RADIUS * scale.radial_scale,
+        "inner_step_radius": INNER_STEP_RADIUS * scale.radial_scale,
+        "inner_shoulder_radius": INNER_SHOULDER_RADIUS * scale.radial_scale,
+        "inner_wall_radius": INNER_WALL_RADIUS * scale.radial_scale,
+        "bottom_outer_radius": BOTTOM_OUTER_RADIUS * scale.radial_scale,
+        "body_outer_radius": BODY_OUTER_RADIUS * scale.radial_scale,
+        "top_outer_radius": TOP_OUTER_RADIUS * scale.radial_scale,
+        "min_z": BASE_MIN_Z * scale.axial_scale,
+        "max_z": BASE_MAX_Z * scale.axial_scale,
+        "height": BASE_HEIGHT * scale.axial_scale,
+        "radial_scale": scale.radial_scale,
+        "axial_scale": scale.axial_scale,
+        "source": scale.source,
+    }
+
+
+def scale_from_motor(
+    *,
+    motor_radial_diameter_mm: float,
+    motor_axis_length_mm: float,
+    radial_clearance_mm: float = 14.0,
+    reducer_axial_allowance_mm: float = 42.0,
+    min_radial_scale: float = 0.45,
+    max_radial_scale: float = 1.50,
+    min_axial_scale: float = 0.55,
+    max_axial_scale: float = 1.80,
+) -> HousingScale:
+    target_inner_radius = motor_radial_diameter_mm / 2.0 + radial_clearance_mm
+    radial_scale = target_inner_radius / INNER_WALL_RADIUS
+    target_height = motor_axis_length_mm + reducer_axial_allowance_mm
+    axial_scale = target_height / BASE_HEIGHT
+    return HousingScale(
+        radial_scale=max(min_radial_scale, min(max_radial_scale, radial_scale)),
+        axial_scale=max(min_axial_scale, min(max_axial_scale, axial_scale)),
+        source="computed_from_motor_bbox",
+    )
+
+
+def _polar_points(radius: float, start_degrees: float, count: int):
+    return [
+        (
+            radius * math.cos(math.radians(start_degrees + 360.0 * index / count)),
+            radius * math.sin(math.radians(start_degrees + 360.0 * index / count)),
+        )
+        for index in range(count)
+    ]
+
+
+def _radial_point(radius: float, angle_degrees: float, z: float) -> cq.Vector:
+    angle = math.radians(angle_degrees)
+    return cq.Vector(radius * math.cos(angle), radius * math.sin(angle), z)
+
+
+def _radial_direction(angle_degrees: float) -> cq.Vector:
+    angle = math.radians(angle_degrees)
+    return cq.Vector(math.cos(angle), math.sin(angle), 0.0)
+
+
+def build_body(scale: HousingScale = HousingScale()):
+    rd = scale.radial_scale
+    zd = scale.axial_scale
+
+    def r(value: float) -> float:
+        return value * rd
+
+    def z(value: float) -> float:
+        return value * zd
+
+    # Exact circular-arc midpoints for the two revolved outer blends.
+    lower_arc_mid = (r(78.8397459621556), z(-8.66025403784439))
+    upper_arc_mid = (r(83.1458565330652), z(71.9211556282713))
+
+    radial_section = (
+        cq.Workplane("XZ")
+        .moveTo(r(INNER_BOTTOM_RADIUS), z(-18.0))
+        .lineTo(r(BOTTOM_OUTER_RADIUS), z(-18.0))
+        .lineTo(r(BOTTOM_OUTER_RADIUS), z(-13.6602540378))
+        .threePointArc(lower_arc_mid, (r(BODY_OUTER_RADIUS), z(-5.0)))
+        .lineTo(r(BODY_OUTER_RADIUS), z(68.3856217223))
+        .threePointArc(upper_arc_mid, (r(TOP_OUTER_RADIUS), z(75.0)))
+        .lineTo(r(TOP_OUTER_RADIUS), z(92.0))
+        .lineTo(r(INNER_WALL_RADIUS), z(92.0))
+        .lineTo(r(INNER_WALL_RADIUS), z(0.0))
+        .lineTo(r(INNER_SHOULDER_RADIUS), z(0.0))
+        .lineTo(r(INNER_SHOULDER_RADIUS), z(-3.0))
+        .lineTo(r(INNER_STEP_RADIUS), z(-3.0))
+        .lineTo(r(INNER_STEP_RADIUS), z(-5.0))
+        .lineTo(r(INNER_BOTTOM_RADIUS), z(-5.0))
+        .close()
+    )
+    return radial_section.revolve(360.0, (0.0, 0.0), (0.0, 1.0))
+
+
+def build(scale: HousingScale = HousingScale()):
+    rd = scale.radial_scale
+    zd = scale.axial_scale
+
+    def r(value: float) -> float:
+        return value * rd
+
+    def z(value: float) -> float:
+        return value * zd
+
+    part = build_body(scale)
+
+    # Ten Ø5 blind drilled holes, equally spaced on a Ø135 pitch circle.
+    drill_tip_height = z(1.5021515475689)
+    for x, y in _polar_points(r(67.5), 18.0, 10):
+        straight_hole = cq.Solid.makeCylinder(
+            r(2.5), z(10.0), cq.Vector(x, y, z(-18.0)), cq.Vector(0.0, 0.0, 1.0)
+        )
+        drill_tip = cq.Solid.makeCone(
+            r(2.5),
+            0.0,
+            drill_tip_height,
+            cq.Vector(x, y, z(-8.0)),
+            cq.Vector(0.0, 0.0, 1.0),
+        )
+        part = part.cut(straight_hole).cut(drill_tip)
+
+    # Four Ø2.5 blind holes opening at z=0, with 118-degree drill tips.
+    small_tip_height = z(0.75107577378445)
+    for x, y in _polar_points(r(71.875), 0.0, 4):
+        straight_hole = cq.Solid.makeCylinder(
+            r(1.25), z(4.24892422621555), cq.Vector(x, y, z(0.0)), cq.Vector(0.0, 0.0, -1.0)
+        )
+        drill_tip = cq.Solid.makeCone(
+            r(1.25),
+            0.0,
+            small_tip_height,
+            cq.Vector(x, y, z(-4.24892422621555)),
+            cq.Vector(0.0, 0.0, -1.0),
+        )
+        part = part.cut(straight_hole).cut(drill_tip)
+
+    # Eight radial Ø6.6 holes with 90-degree countersinks around the top rim.
+    for angle in range(0, 360, 45):
+        direction = _radial_direction(float(angle))
+        straight_hole = cq.Solid.makeCylinder(
+            r(3.3), r(3.9), _radial_point(r(78.0), float(angle), z(85.1)), direction
+        )
+        countersink = cq.Solid.makeCone(
+            r(3.3),
+            r(6.4),
+            r(3.1),
+            _radial_point(r(81.9), float(angle), z(85.1)),
+            direction,
+        )
+        part = part.cut(straight_hole).cut(countersink)
+
+    return part
+
+
+def export_scaled(output: Path, scale: HousingScale) -> None:
+    cq.exporters.export(build(scale), str(output))
+
+
+if __name__ == "__main__":
+    output = Path(__file__).resolve().with_name("gear_housing.step")
+    export_scaled(output, HousingScale())
+    print(output)