feat: Item baseclass, and fasteners

nhf/__init__.py

@@ -1 +1,2 @@
 from nhf.materials import Material, Role
+from nhf.parts.item import Item

nhf/materials.py

@@ -9,6 +9,11 @@ def _color(name: str, alpha: float) -> Cq.Color:
     r, g, b, _ = Cq.Color(name).toTuple()
     return Cq.Color(r, g, b, alpha)
 
+
+KEY_ROLE = 'role'
+KEY_MATERIAL = 'material'
+KEY_ITEM = 'item'
+
 class Role(Flag):
     """
     Describes the role of a part
@@ -26,7 +31,10 @@ class Role(Flag):
     STRUCTURE = auto()
     DECORATION = auto()
     ELECTRONIC = auto()
+
+    # Fasteners, etc.
     CONNECTION = auto()
+    HANDLE = auto()
 
     # Parent and child components in a load bearing joint
 
@@ -54,7 +62,8 @@ ROLE_COLOR_MAP = {
     Role.STRUCTURE:  _color('gray', 0.4),
     Role.DECORATION: _color('lightseagreen', 0.4),
     Role.ELECTRONIC: _color('mediumorchid', 0.5),
-    Role.CONNECTION: _color('steelblue3', 0.8)
+    Role.CONNECTION: _color('steelblue3', 0.8),
+    Role.HANDLE:     _color('tomato4', 0.8),
 }
 
 
@@ -91,10 +100,10 @@ def add_with_material_role(
     metadata = {}
     color = None
     if material:
-        metadata["material"] = material
+        metadata[KEY_MATERIAL] = material
         color = material.color
     if role:
-        metadata["role"] = role
+        metadata[KEY_ROLE] = role
         color = role.color_avg()
     if len(metadata) == 0:
         metadata = None
@@ -106,29 +115,16 @@ Cq.Assembly.addS = add_with_material_role
 
 def color_by_material(self: Cq.Assembly) -> Cq.Assembly:
     for _, a in self.traverse():
-        if 'material' not in a.metadata:
+        if KEY_MATERIAL not in a.metadata:
             continue
-        a.color = a.metadata["material"].color
+        a.color = a.metadata[KEY_MATERIAL].color
     return self
 Cq.Assembly.color_by_material = color_by_material
 def color_by_role(self: Cq.Assembly, avg: bool = True) -> Cq.Assembly:
     for _, a in self.traverse():
-        if 'role' not in a.metadata:
+        if KEY_ROLE not in a.metadata:
             continue
-        role = a.metadata["role"]
+        role = a.metadata[KEY_ROLE]
         a.color = role.color_avg() if avg else role.color_head()
     return self
 Cq.Assembly.color_by_role = color_by_role
-
-def total_mass(self: Cq.Assembly) -> float:
-    """
-    Calculates the total mass in units of g
-    """
-    total = 0.0
-    for _, a in self.traverse():
-        if 'material' not in a.metadata:
-            continue
-        vol = a.toCompound().Volume()
-        total += vol * a.metadata['material'].density
-    return total / 1000.0
-Cq.Assembly.total_mass = total_mass

nhf/parts/fasteners.py

@@ -0,0 +1,91 @@
+from dataclasses import dataclass
+import math
+import cadquery as Cq
+from nhf import Item, Role
+import nhf.utils
+
+@dataclass(frozen=True)
+class ThreaddedKnob(Item):
+    """
+    Sourced from:
+
+    > Othmro Black 12mm(M12) x 50mm Thread Replacement Star Hand Knob Tightening
+    > Screws
+    """
+    diam_rod: float
+    height_rod: float
+    diam_knob: float
+
+    diam_neck: float
+    height_neck: float
+    height_knob: float
+
+    @property
+    def name(self) -> str:
+        return f"Knob-M{int(self.diam_rod)}-{int(self.height_rod)}mm"
+
+    def generate(self) -> Cq.Assembly:
+        print(self.name)
+        knob = Cq.Solid.makeCylinder(
+            radius=self.diam_knob / 2,
+            height=self.height_knob,
+        )
+        neck = Cq.Solid.makeCylinder(
+            radius=self.diam_neck / 2,
+            height=self.height_neck,
+        )
+        rod = (
+            Cq.Workplane('XY')
+            .cylinder(
+                radius=self.diam_rod / 2,
+                height=self.height_rod,
+                centered=(True, True, False))
+        )
+        rod.faces("<Z").tag("tip")
+        rod.faces(">Z").tag("root")
+
+        return (
+            Cq.Assembly()
+            .addS(rod, name="rod", role=Role.CONNECTION)
+            .addS(neck, name="neck", role=Role.HANDLE,
+                  loc=Cq.Location((0, 0, self.height_rod)))
+            .addS(knob, name="knob", role=Role.HANDLE,
+                  loc=Cq.Location((0, 0, self.height_rod + self.height_neck)))
+        )
+
+
+@dataclass(frozen=True)
+class HexNut(Item):
+    diam: float
+    pitch: float
+
+    # FIXME: Measure these
+    m: float
+    s: float
+
+    def __post_init__(self):
+        assert self.s > self.diam
+
+    @property
+    def name(self):
+        return f"HexNut-M{int(self.diam)}-{self.pitch}"
+
+    @property
+    def role(self):
+        return Role.CONNECTION
+
+    def generate(self) -> Cq.Workplane:
+        print(self.name)
+        r = self.s / math.sqrt(3)
+        result = (
+            Cq.Workplane("XY")
+            .sketch()
+            .regularPolygon(r=r, n=6)
+            .circle(r=self.diam/2, mode='s')
+            .finalize()
+            .extrude(self.m)
+        )
+        result.faces("<Z").tag("bot")
+        result.faces(">Z").tag("top")
+        result.copyWorkplane(Cq.Workplane('XY')).tagPlane("dir", direction="+X")
+        return result

nhf/parts/item.py

@@ -0,0 +1,67 @@
+from typing import Union, Optional
+from collections import Counter
+from dataclasses import dataclass
+import cadquery as Cq
+from nhf.materials import Role, KEY_ROLE, KEY_ITEM
+
+@dataclass(frozen=True)
+class Item:
+    """
+    A pre-fabricated item
+    """
+    mass: float
+
+    #@property
+    #def mass(self) -> float:
+    #    """
+    #    Mass, in grams
+    #    """
+    #    return self._mass
+
+    #@mass.setter
+    #def mass(self, value):
+    #    assert value >= 0, "Mass cannot be negative"
+    #    self._mass = value
+
+    @property
+    def name(self) -> str:
+        pass
+
+    @property
+    def role(self) -> Optional[Role]:
+        return None
+
+    def generate(self) -> Union[Cq.Assembly, Cq.Workplane]:
+        """
+        Creates an assembly for this item. Subclass should implement this
+        """
+        return Cq.Assembly()
+
+    def assembly(self) -> Cq.Assembly:
+        """
+        Interface for creating assembly with the necessary metadata
+        """
+        a = self.generate()
+        if isinstance(a, Cq.Workplane):
+            a = Cq.Assembly(a)
+            if role := self.role:
+                a.metadata[KEY_ROLE] = role
+                a.color = role.color_avg()
+        assert isinstance(a, Cq.Assembly)
+        assert KEY_ITEM not in a.metadata
+        a.metadata[KEY_ITEM] = self
+        return a
+
+    @staticmethod
+    def count(a: Cq.Assembly) -> Counter:
+        """
+        Counts the number of items
+        """
+        occ = Counter()
+        for _, obj in a.traverse():
+            if KEY_ITEM not in obj.metadata:
+                continue
+            item = obj.metadata[KEY_ITEM]
+            assert isinstance(item, Item)
+            occ[item.name] += 1
+        return occ

nhf/utils.py

@@ -6,6 +6,7 @@ import functools
 import cadquery as Cq
 from nhf import Role
 from typing import Union, Tuple, cast
+from nhf.materials import KEY_ITEM, KEY_MATERIAL
 
 # Bug fixes
 def _subloc(self, name: str) -> Tuple[Cq.Location, str]:
@@ -204,3 +205,20 @@ def get_abs_location(self: Cq.Assembly,
     return loc
 
 Cq.Assembly.get_abs_location = get_abs_location
+
+
+# Tallying functions
+
+def total_mass(self: Cq.Assembly) -> float:
+    """
+    Calculates the total mass in units of g
+    """
+    total = 0.0
+    for _, a in self.traverse():
+        if item := a.metadata.get(KEY_ITEM):
+            total += item.mass
+        elif material := a.metadata.get(KEY_MATERIAL):
+            vol = a.toCompound().Volume()
+            total += (vol / 1000) * material.density
+    return total
+Cq.Assembly.total_mass = total_mass