Cleanup dovetail geometry

nhf/touhou/shiki_eiki/crown.py

@@ -1,10 +1,17 @@
-import math
-from dataclasses import dataclass, field
-import cadquery as Cq
 from nhf import Material, Role
 from nhf.build import Model, target, assembly, TargetKind
 import nhf.utils
 
+import math
+from dataclasses import dataclass, field
+from enum import Enum
+import cadquery as Cq
+
+class AttachPoint(Enum):
+    DOVETAIL_IN = 1
+    DOVETAIL_OUT = 2
+    NONE = 3
+
 @dataclass
 class Crown(Model):
 
@@ -24,6 +31,7 @@ class Crown(Model):
     side_guard_channel_height: float = 10
     side_guard_hole_height: float = 15.0
     side_guard_hole_diam: float = 1.5
+    side_guard_dovetail_height: float = 30.0
 
     material: Material = Material.METAL_BRASS
     material_side: Material = Material.PLASTIC_PLA
@@ -365,36 +373,36 @@ class Crown(Model):
         dx = self.side_guard_thickness / 2
         wire = Cq.Wire.makePolygon([
             (dx * 0.5, 0),
-            (dx * 0.8, dx),
+            (dx * 0.7, dx),
-            (-dx * 0.8, dx),
+            (-dx * 0.7, dx),
             (-dx * 0.5, 0),
         ], close=True)
         return Cq.Solid.extrudeLinear(
             wire,
             [],
-            (0,0,self.height/3),
+            (0,0,dx + self.side_guard_dovetail_height),
-        )
+        ).moved((0, 0, -dx))
 
-    def side_guard(self, attach_left: bool = True, attach_right: bool = False) -> Cq.Workplane:
+    def side_guard(self, attach_left: AttachPoint, attach_right: AttachPoint) -> Cq.Workplane:
         """
         Constructs the side guard using a cone. Via Gauss's Theorema Egregium,
         the surface of the cone can be deformed into a plane.
         """
-        angle = 360 / 5
+        angle_span = 360 / 5
         outer = Cq.Solid.makeCone(
             radius1=self.radius_lower + self.side_guard_thickness,
             radius2=self.radius_upper + self.side_guard_thickness,
             height=self.height,
-            angleDegrees=angle,
+            angleDegrees=angle_span,
         )
         inner = Cq.Solid.makeCone(
             radius1=self.radius_lower,
             radius2=self.radius_upper,
             height=self.height,
-            angleDegrees=angle,
+            angleDegrees=angle_span,
         )
-        shell = (outer - inner).rotate((0,0,0), (0,0,1), -angle/2)
+        shell = (outer - inner).rotate((0,0,0), (0,0,1), -angle_span/2)
-        dx = math.sin(math.radians(angle / 2)) * (self.radius_middle + self.side_guard_thickness)
+        dx = math.sin(math.radians(angle_span / 2)) * (self.radius_middle + self.side_guard_thickness)
         profile = (
             Cq.Workplane('YZ')
             .polyline([
@@ -408,16 +416,16 @@ class Crown(Model):
             .extrude(self.radius_upper + self.side_guard_thickness)
             .val()
         )
-        channel = (
+        #channel = (
-            Cq.Solid.makeCylinder(
+        #    Cq.Solid.makeCylinder(
-                radius=self.side_guard_channel_radius + 1.0,
+        #        radius=self.side_guard_channel_radius + 1.0,
-                height=self.side_guard_channel_height,
+        #        height=self.side_guard_channel_height,
-            ) - Cq.Solid.makeCylinder(
+        #    ) - Cq.Solid.makeCylinder(
-                radius=self.side_guard_channel_radius,
+        #        radius=self.side_guard_channel_radius,
-                height=self.side_guard_channel_height,
+        #        height=self.side_guard_channel_height,
-            )
+        #    )
-        )
+        #)
-        result = shell * profile - channel
+        result = shell * profile# - channel
         for i in [-2, -1, 0, 1, 2]:
             phi = i * (math.pi / 14)
             hole = Cq.Solid.makeCylinder(
@@ -431,10 +439,45 @@ class Crown(Model):
         radius_attach = self.radius_lower + self.side_guard_thickness / 2
         # tilt the dovetail by radius differential
         angle_tilt = math.degrees(math.atan2(self.radius_middle - self.radius_lower, self.height / 2))
-        print(angle_tilt)
         dovetail = self.side_guard_dovetail()
-        loc_dovetail = Cq.Location.rot2d(angle / 2) * Cq.Location(radius_attach, 0, 0, 0, angle_tilt, 0) * Cq.Location.rot2d(180)
+        loc_dovetail_left = Cq.Location.rot2d(angle_span / 2) * Cq.Location(radius_attach, 0, 0, 0, angle_tilt, 0)
-        return result - dovetail.moved(loc_dovetail)
+        loc_dovetail_right = Cq.Location.rot2d(-angle_span / 2) * Cq.Location(radius_attach, 0, 0, 0, angle_tilt, 0)
+
+        match attach_left:
+            case AttachPoint.DOVETAIL_IN:
+                loc_dovetail_left *= Cq.Location.rot2d(180)
+                result = result - dovetail.moved(loc_dovetail_left)
+            case AttachPoint.DOVETAIL_OUT:
+                result = result + dovetail.moved(loc_dovetail_left)
+            case AttachPoint.NONE:
+                pass
+        match attach_right:
+            case AttachPoint.DOVETAIL_IN:
+                result = result - dovetail.moved(loc_dovetail_right)
+            case AttachPoint.DOVETAIL_OUT:
+                loc_dovetail_right *= Cq.Location.rot2d(180)
+                result = result + dovetail.moved(loc_dovetail_right)
+            case AttachPoint.NONE:
+                pass
+        # Remove parts below the horizontal
+        cut_h = self.radius_lower
+        result -= Cq.Solid.makeCylinder(
+            radius=self.radius_lower + self.side_guard_thickness,
+            height=cut_h).moved((0,0,-cut_h))
+        return result
+
+    @target(name="side_guard_2")
+    def side_guard_2(self) -> Cq.Workplane:
+        return self.side_guard(
+            attach_left=AttachPoint.DOVETAIL_OUT,
+            attach_right=AttachPoint.DOVETAIL_IN,
+        )
+    @target(name="side_guard_3")
+    def side_guard_3(self) -> Cq.Workplane:
+        return self.side_guard(
+            attach_left=AttachPoint.DOVETAIL_IN,
+            attach_right=AttachPoint.DOVETAIL_IN,
+        )
 
     def front_surrogate(self) -> Cq.Workplane:
         """
@@ -478,7 +521,7 @@ class Crown(Model):
         """
         New assembly using conformal mapping on the cone.
         """
-        side_guard = self.side_guard()
+        side_guard = self.side_guard_2()
         a = Cq.Assembly()
         for i in range(1,5):
             a = a.addS(