feat: Elbow joint

nhf/build.py

@@ -23,6 +23,8 @@ from colorama import Fore, Style
 import cadquery as Cq
 import nhf.checks as NC
 
+TOL=1e-6
+
 class TargetKind(Enum):
 
     STL = "stl",
@@ -70,7 +72,7 @@ class Target:
             if isinstance(x, Cq.Workplane):
                 x = x.val()
             if isinstance(x, Cq.Assembly):
-                x = x.toCompound()
+                x = x.toCompound().fuse(tol=TOL)
             x.exportStl(path, **self.kwargs)
         elif self.kind == TargetKind.DXF:
             assert isinstance(x, Cq.Workplane)

nhf/touhou/houjuu_nue/parts.py

@@ -1,4 +1,4 @@
-from dataclasses import dataclass
+from dataclasses import dataclass, field
 from typing import Optional, Tuple
 import cadquery as Cq
 from nhf import Role
@@ -8,6 +8,67 @@ import nhf.utils
 
 TOL = 1e-6
 
+@dataclass
+class Beam:
+    """
+    A I-shaped spine with two feet
+    """
+
+    foot_length: float = 40.0
+    foot_width: float = 20.0
+    foot_height: float = 5.0
+    spine_thickness: float = 4.0
+    spine_length: float = 10.0
+    total_height: float = 50.0
+
+    hole_diam: float = 8.0
+    # distance between the centres of the two holes
+    hole_dist: float = 24.0
+
+    def __post_init__(self):
+        assert self.spine_height > 0
+        assert self.hole_diam + self.hole_dist < self.foot_length
+        assert self.hole_dist - self.hole_diam >= self.spine_length
+
+    @property
+    def spine_height(self):
+        return self.total_height - self.foot_height * 2
+
+    def foot(self) -> Cq.Workplane:
+        """
+        just one foot
+        """
+        dx = self.hole_dist / 2
+        result = (
+            Cq.Workplane('XZ')
+            .box(self.foot_length, self.foot_width, self.foot_height,
+                 centered=(True, True, False))
+            .faces(">Y")
+            .workplane()
+            .pushPoints([(dx, 0), (-dx, 0)])
+            .hole(self.hole_diam)
+        )
+        plane = result.faces(">Y").workplane()
+        plane.moveTo(dx, 0).tagPlane("conn1")
+        plane.moveTo(-dx, 0).tagPlane("conn0")
+        return result
+
+    def beam(self) -> Cq.Assembly:
+        beam = (
+            Cq.Workplane('XZ')
+            .box(self.spine_length, self.spine_thickness, self.spine_height)
+        )
+        h = self.spine_height / 2 + self.foot_height
+        result = (
+            Cq.Assembly()
+            .add(beam, name="beam")
+            .add(self.foot(), name="top",
+                 loc=Cq.Location((0, h, 0)))
+            .add(self.foot(), name="bot",
+                 loc=Cq.Location((0, -h, 0), (0, 0, 1), 180))
+        )
+        return result
+
 @dataclass
 class DiskJoint(Model):
     """
@@ -76,8 +137,18 @@ class DiskJoint(Model):
 
     @property
     def housing_upper_carve_offset(self) -> float:
+        """
+        Distance between the spring track and the outside of the upper housing
+        """
         return self.housing_thickness + self.disk_thickness - self.spring_height
 
+    @property
+    def housing_upper_dz(self) -> float:
+        """
+        Distance between the default upper housing location and the median line
+        """
+        return self.total_thickness / 2 - self.housing_thickness
+
     @property
     def radius_spring_internal(self):
         return self.radius_spring - self.spring_thickness
@@ -175,8 +246,8 @@ class DiskJoint(Model):
                 length=self.spring_tail_length,
                 width=self.spring_thickness,
                 height=self.housing_thickness
-            ).located(Cq.Location((0, self.radius_spring_internal, 0))))
+            ).located(Cq.Location((0, -self.radius_spring, 0))))
-        ).rotate((0, 0, 0), (0, 0, 1), 180 + self.spring_angle - self.spring_angle_shift)
+        ).rotate((0, 0, 0), (0, 0, 1), self.spring_angle - self.spring_angle_shift)
         result = (
             Cq.Workplane('XY')
             .cylinder(
@@ -185,8 +256,8 @@ class DiskJoint(Model):
                 centered=(True, True, False),
             )
         )
-        result.faces(">Z").tag("mate")
+        result.faces("<Z").tag("mate")
-        result.copyWorkplane(Cq.Workplane('XY')).tagPlane("dir", direction="+X")
+        result.copyWorkplane(Cq.Workplane('XY')).tagPlane("dir", direction="-X")
         result = result.faces(">Z").hole(self.radius_axle * 2)
 
         # tube which holds the spring interior
@@ -203,14 +274,12 @@ class DiskJoint(Model):
             result = result.union(tube)
         wall = (
             self.wall()
-            .rotate((0, 0, 0), (0, 0, 1), self.tongue_span)
+            .located(Cq.Location((0, 0, -self.disk_thickness-self.wall_inset)))
-            .mirror("XY")
-            .located(Cq.Location((0, 0, self.disk_thickness + self.housing_thickness + self.wall_inset)))
         )
         result = (
             result
+            .cut(carve.located(Cq.Location((0, 0, -self.housing_upper_carve_offset))))
             .union(wall, tol=TOL)
-            .cut(carve.located(Cq.Location((0, 0, self.housing_upper_carve_offset))))
         )
         return result
 
@@ -256,6 +325,104 @@ class DiskJoint(Model):
         )
         return result.solve()
 
+@dataclass
+class ElbowJoint:
+    """
+    Creates the elbow and wrist joints.
+
+    This consists of a disk joint, where each side of the joint has mounting
+    holes for connection to the exoskeleton. Each side 2 mounting feet on the
+    top and bottom, and each foot has 2 holes.
+
+    On the parent side, additional bolts are needed to clamp the two sides of
+    the housing together.
+    """
+
+    disk_joint: DiskJoint = field(default_factory=lambda: DiskJoint(
+        movement_angle=60,
+    ))
+
+    # Distance between the child/parent arm to the centre
+    child_arm_radius: float = 40.0
+    parent_arm_radius: float = 40.0
+
+    child_beam: Beam = field(default_factory=lambda: Beam())
+    parent_beam: Beam = field(default_factory=lambda: Beam(
+        spine_thickness=8.0,
+    ))
+    parent_arm_span: float = 40.0
+    # Angle of the beginning of the parent arm
+    parent_arm_angle: float = 180.0
+    parent_binding_hole_radius: float = 30.0
+
+    # Size of the mounting holes
+    hole_diam: float = 8.0
+
+    def __post_init__(self):
+        assert self.child_arm_radius > self.disk_joint.radius_housing
+        assert self.parent_arm_radius > self.disk_joint.radius_housing
+        self.disk_joint.tongue_length = self.child_arm_radius - self.disk_joint.radius_disk
+        assert self.disk_joint.movement_angle < self.parent_arm_angle < 360 - self.parent_arm_span
+        assert self.parent_binding_hole_radius - self.hole_diam / 2 > self.disk_joint.radius_housing
+
+    def child_joint(self) -> Cq.Assembly:
+        angle = -self.disk_joint.tongue_span / 2
+        dz = self.disk_joint.disk_thickness / 2
+        result = (
+            self.child_beam.beam()
+            .add(self.disk_joint.disk(), name="disk",
+                 loc=Cq.Location((-self.child_arm_radius, 0, -dz), (0, 0, 1), angle))
+        )
+        return result
+
+    def parent_joint_bot(self) -> Cq.Workplane:
+        return self.disk_joint.housing_lower()
+
+    def parent_joint_top(self):
+        axial_offset = Cq.Location((self.parent_arm_radius, 0, 0))
+        housing_dz = self.disk_joint.housing_upper_dz
+        conn_h = self.parent_beam.spine_thickness
+        connector = (
+            Cq.Solid.makeCylinder(
+                height=conn_h,
+                radius=self.parent_arm_radius,
+                angleDegrees=self.parent_arm_span)
+            .cut(Cq.Solid.makeCylinder(
+                height=conn_h,
+                radius=self.disk_joint.radius_housing,
+            ))
+            .located(Cq.Location((0, 0, -conn_h / 2)))
+            .rotate((0,0,0), (0,0,1), 180-self.parent_arm_span / 2)
+        )
+        housing = self.disk_joint.housing_upper()
+        result = (
+            Cq.Assembly()
+            .add(housing, name="housing",
+                 loc=axial_offset * Cq.Location((0, 0, housing_dz)))
+            .add(connector, name="connector",
+                 loc=axial_offset)
+            .add(self.parent_beam.beam(), name="beam")
+        )
+        return result
+
+    def assembly(self, angle: float = 0) -> Cq.Assembly:
+        da = self.disk_joint.tongue_span / 2
+        result = (
+            Cq.Assembly()
+            .add(self.child_joint(), name="child", color=Role.CHILD.color)
+            .add(self.parent_joint_bot(), name="parent_bot", color=Role.CASING.color)
+            .add(self.parent_joint_top(), name="parent_top", color=Role.PARENT.color)
+            .constrain("parent_bot", "Fixed")
+        )
+        self.disk_joint.add_constraints(
+            result,
+            housing_lower="parent_bot",
+            housing_upper="parent_top/housing",
+            disk="child/disk",
+            angle=(0, 0, angle + da),
+        )
+        return result.solve()
+
 if __name__ == '__main__':
     p = DiskJoint()
     p.build_all()

nhf/touhou/houjuu_nue/wing.py

@@ -290,7 +290,6 @@ class WingProfile:
     def elbow_to_abs(self, x: float, y: float) -> Tuple[float, float]:
         elbow_x = self.elbow_x + x * self.elbow_c - y * self.elbow_s
         elbow_y = self.elbow_y + x * self.elbow_s + y * self.elbow_c
-        print(f"c={self.elbow_c}, s={self.elbow_s}, x={elbow_x}, y={elbow_y}")
         return elbow_x, elbow_y
     def wrist_to_abs(self, x: float, y: float) -> Tuple[float, float]:
         wrist_x = self.wrist_x + x * self.wrist_c - y * self.wrist_s