feat: 2 segment wing root

nhf/touhou/houjuu_nue/__init__.py

@@ -1,15 +1,42 @@
+"""
+This cosplay consists of 3 components:
+
+## Trident
+
+The trident is composed of individual segments, made of acrylic, and a 3D
+printed head (convention rule prohibits metal) with a metallic paint. To ease
+transportation, the trident handle has individual segments with threads and can
+be assembled on site.
+
+## Snake
+
+A 3D printed snake with a soft material so it can wrap around and bend
+
+## Wings
+
+This is the crux of the cosplay and the most complex component. The wings mount
+on a wearable harness. Each wing consists of 4 segments with 3 joints. Parts of
+the wing which demands transluscency are created from 1/16" acrylic panels.
+These panels serve double duty as the exoskeleton.
+
+The wings are labeled r1,r2,r3,l1,l2,l3. The segments of the wings are labeled
+from root to tip s0 (root), s1, s2, s3. The joints are named (from root to tip)
+shoulder, elbow, wrist in analogy with human anatomy.
+"""
 from dataclasses import dataclass
 import unittest
 import cadquery as Cq
 import nhf.joints
 from nhf import Material
+import nhf.touhou.houjuu_nue.wing as MW
 
 @dataclass(frozen=True)
 class Parameters:
+    """
+    Defines dimensions for the Houjuu Nue cosplay
+    """
 
-    """
+    # Thickness of the exoskeleton panel in millimetres
-    Thickness of the exoskeleton panel in millimetres
-    """
     panel_thickness: float = 25.4 / 16
 
     # Harness
@@ -28,12 +55,11 @@ class Parameters:
     ]
 
     # Holes drilled onto harness for attachment with HS joint
-    harness_to_wing_base_hole_diam = 6
+    harness_to_root_conn_diam = 6
 
     # Wing root properties
-    """
+    #
-    The Houjuu-Scarlett joint mechanism at the base of the wing
+    # The Houjuu-Scarlett joint mechanism at the base of the wing
-    """
     hs_joint_base_width = 85
     hs_joint_base_thickness = 10
     hs_joint_ring_thickness = 5
@@ -49,12 +75,8 @@ class Parameters:
     hs_joint_axis_cbore_diam = 20
     hs_joint_axis_cbore_depth = 3
 
-
+    # Exterior radius of the wing root assembly
-    """
+    wing_root_radius = 40
-    Radius of the mounting mechanism of the wing root. This is constrained by
-    the size of the harness.
-    """
-    root_radius: float = 60
 
     """
     Heights for various wing joints, where the numbers start from the first joint.
@@ -64,6 +86,10 @@ class Parameters:
     wing_r2_height = 100
     wing_r3_height = 100
 
+    def __post_init__(self):
+        assert self.wing_root_radius > self.hs_joint_radius,\
+            "Wing root must be large enough to accomodate joint"
+
 
     def print_geometries(self):
         return [
@@ -95,7 +121,7 @@ class Parameters:
                 sketch
                 .push(conn)
                 .tag(tag)
-                .circle(self.harness_to_wing_base_hole_diam / 2, mode='s')
+                .circle(self.harness_to_root_conn_diam / 2, mode='s')
                 .reset()
             )
         return sketch
@@ -171,7 +197,7 @@ class Parameters:
             .workplane()
             .pushPoints(conn)
             .cboreHole(
-                diameter=self.harness_to_wing_base_hole_diam,
+                diameter=self.harness_to_root_conn_diam,
                 cboreDiameter=self.hs_joint_corner_cbore_diam,
                 cboreDepth=self.hs_joint_corner_cbore_depth)
         )
@@ -245,23 +271,16 @@ class Parameters:
         )
         return result
 
-    def wing_root(self,
+    def wing_root(self) -> Cq.Shape:
-                  side_width=30,
-                  side_height=100) -> Cq.Shape:
         """
         Generate the wing root which contains a Hirth joint at its base and a
         rectangular opening on its side, with the necessary interfaces.
         """
-        result = (
+        return MW.wing_base().val()#self.wing_root_radius)
-            Cq.Workplane("XY")
+
-            .circle(self.root_radius)
+    ######################
-            .transformed(offset=Cq.Vector(80, 0, 80),
+    #    Assemblies      #
-                         rotate=Cq.Vector(0, 45, 0))
+    ######################
-            .rect(side_width, side_height)
-            .loft()
-            .val()
-        )
-        return result
 
     def harness_assembly(self):
         harness = self.harness()

nhf/touhou/houjuu_nue/wing.py

@@ -0,0 +1,162 @@
+import math
+import cadquery as Cq
+
+def wing_root_profiles(
+        base_sweep=150,
+        wall_thickness=8,
+        base_radius=60,
+        middle_offset=30,
+        conn_width=40,
+        conn_height=100) -> tuple[Cq.Wire, Cq.Wire]:
+    assert base_sweep < 180
+    assert middle_offset > 0
+    theta = math.pi * base_sweep / 180
+    c, s = math.cos(theta), math.sin(theta)
+    c_1, s_1 = math.cos(theta * 0.75), math.sin(theta * 0.75)
+    c_2, s_2 = math.cos(theta / 2), math.sin(theta / 2)
+    r1 = base_radius
+    r2 = base_radius - wall_thickness
+    base = (
+        Cq.Sketch()
+        .arc(
+            (c * r1, s * r1),
+            (c_1 * r1, s_1 * r1),
+            (c_2 * r1, s_2 * r1),
+        )
+        .arc(
+            (c_2 * r1, s_2 * r1),
+            (r1, 0),
+            (c_2 * r1, -s_2 * r1),
+        )
+        .arc(
+            (c_2 * r1, -s_2 * r1),
+            (c_1 * r1, -s_1 * r1),
+            (c * r1, -s * r1),
+        )
+        .segment(
+            (c * r1, -s * r1),
+            (c * r2, -s * r2),
+        )
+        .arc(
+            (c * r2, -s * r2),
+            (c_1 * r2, -s_1 * r2),
+            (c_2 * r2, -s_2 * r2),
+        )
+        .arc(
+            (c_2 * r2, -s_2 * r2),
+            (r2, 0),
+            (c_2 * r2, s_2 * r2),
+        )
+        .arc(
+            (c_2 * r2, s_2 * r2),
+            (c_1 * r2, s_1 * r2),
+            (c * r2, s * r2),
+        )
+        .segment(
+            (c * r2, s * r2),
+            (c * r1, s * r1),
+        )
+        .assemble(tag="wire")
+        .wires().val()
+    )
+    assert isinstance(base, Cq.Wire)
+
+    # The interior sweep is given by theta, but the exterior sweep exceeds the
+    # interior sweep so the wall does not become thinner towards the edges.
+    # If the exterior sweep is theta', it has to satisfy
+    #
+    # sin(theta) * r2 + wall_thickness = sin(theta') * r1
+    x, y = conn_width / 2, conn_height / 2
+    t = wall_thickness
+    dx = middle_offset
+    middle = (
+        Cq.Sketch()
+        # Interior arc, top point
+        .arc(
+            (x - t, y - t),
+            (x - t + dx, 0),
+            (x - t, -y + t),
+        )
+        .segment(
+            (x - t, -y + t),
+            (-x, -y+t)
+        )
+        .segment((-x, -y))
+        .segment((x, -y))
+        # Outer arc, bottom point
+        .arc(
+            (x, -y),
+            (x + dx, 0),
+            (x, y),
+        )
+        .segment(
+            (x, y),
+            (-x, y)
+        )
+        .segment((-x, y-t))
+        #.segment((x2, a))
+        .close()
+        .assemble(tag="wire")
+        .wires().val()
+    )
+    assert isinstance(middle, Cq.Wire)
+
+    x, y = conn_width / 2, conn_height / 2
+    t = wall_thickness
+    tip = (
+        Cq.Sketch()
+        .segment((-x, y), (x, y))
+        .segment((x, -y))
+        .segment((-x, -y))
+        .segment((-x, -y+t))
+        .segment((x-t, -y+t))
+        .segment((x-t, y-t))
+        .segment((-x, y-t))
+        .close()
+        .assemble(tag="wire")
+        .wires().val()
+    )
+    return base, middle, tip
+def wing_base():
+    root_profile, middle_profile, tip_profile = wing_root_profiles()
+
+    rotate_centre = Cq.Vector(-200, 0, -25)
+    rotate_axis = Cq.Vector(0, 1, 0)
+    terminal_offset = Cq.Vector(-80, 0, 80)
+    terminal_rotate = Cq.Vector(0, -45, 0)
+
+    #middle_profile = middle_profile.moved(Cq.Location((0, 0, -100)))
+    #tip_profile = tip_profile.moved(Cq.Location((0, 0, -200)))
+    middle_profile = middle_profile.rotate(
+        startVector=rotate_centre,
+        endVector=rotate_centre + rotate_axis,
+        angleDegrees = 35,
+    )
+    tip_profile = tip_profile.rotate(
+        startVector=rotate_centre,
+        endVector=rotate_centre + rotate_axis,
+        angleDegrees = 70,
+    )
+    seg1 = (
+        Cq.Workplane('XY')
+        .add(root_profile)
+        .toPending()
+        .transformed(
+            offset=terminal_offset,
+            rotate=terminal_rotate)
+        #.add(middle_profile.moved(Cq.Location((-15, 0, 15))))
+        .add(middle_profile)
+        .toPending()
+        .loft()
+    )
+    seg2 = (
+        Cq.Workplane('XY')
+        .add(middle_profile)
+        .toPending()
+        .workplane()
+        .add(tip_profile)
+        .toPending()
+        .loft()
+    )
+    seg1 = seg1.union(seg2)
+    return seg1