Cosplay/nhf/parts/handle.py

386 lines
12 KiB
Python

"""
This schematics file contains all designs related to tool handles
"""
from dataclasses import dataclass, field
from typing import Union, Optional
import cadquery as Cq
import nhf.parts.metric_threads as metric_threads
import nhf.utils
class Mount:
"""
Describes the internal connection between two cylinders
"""
def diam_insertion_internal(self) -> float:
"""
Diameter of the internal cavity in the insertion
"""
def diam_connector_external(self) -> float:
"""
Diameter of the external size of the connector
"""
def external_thread(self, length: float) -> Cq.Shape:
"""
Generates the external connector
"""
def internal_thread(self, length: float) -> Cq.Shape:
"""
Generates the internal connector
"""
@dataclass
class ThreadedMount(Mount):
pitch: float = 3
# Major diameter of the internal threads, following ISO metric screw thread
# standard. This determines the wall thickness of the insertion.
diam_threading: float = 27
def diam_insertion_internal(self) -> float:
r = metric_threads.metric_thread_major_radius(
self.diam_threading,
self.pitch,
internal=True)
return r * 2
def diam_connector_external(self) -> float:
r = metric_threads.metric_thread_minor_radius(
self.diam_threading,
self.pitch)
return r * 2
def external_thread(self, length: float):
return metric_threads.external_metric_thread(
self.diam_threading,
self.pitch,
length,
top_lead_in=True)
def internal_thread(self, length: float):
return metric_threads.internal_metric_thread(
self.diam_threading,
self.pitch,
length)
@dataclass
class BayonetMount(Mount):
"""
Bayonet type connection
"""
diam_outer: float = 30
diam_inner: float = 27
# Angular span (in degrees) of the slider
pin_span: float = 15
pin_height: float = 5
# Wall at the bottom of the slot
gap: float = 3
# Angular span (in degrees) of the slot
slot_span: float = 90
# Number of pins equally distributed along a circle
n_pin: int = 2
def __post_init__(self):
assert self.diam_outer > self.diam_inner
assert self.n_pin * self.slot_span < 360
assert self.slot_span > self.pin_span
def diam_insertion_internal(self) -> float:
return self.diam_outer
def diam_connector_external(self) -> float:
return self.diam_inner
def external_thread(self, length: float):
assert length > self.pin_height + self.gap
pin = (
Cq.Workplane('XY')
.cylinder(
height=self.pin_height,
radius=self.diam_outer / 2,
angle=self.pin_span,
centered=(True, True, False))
.copyWorkplane(Cq.Workplane('XY'))
.cylinder(
height=self.pin_height,
radius=self.diam_inner / 2,
centered=(True, True, False),
combine="cut")
.val()
)
result = (
Cq.Workplane('XY')
.workplane(offset=self.gap)
.polarArray(radius=0, startAngle=0, angle=360, count=self.n_pin)
.eachpoint(lambda loc: pin.located(loc), combine='a')
.clean()
)
return result
def internal_thread(self, length: float):
assert length > self.pin_height + self.gap
slot = (
Cq.Workplane('XY')
.cylinder(
height=length - self.gap,
radius=self.diam_outer / 2,
angle=self.pin_span,
centered=(True, True, False)
)
.copyWorkplane(Cq.Workplane('XY'))
.cylinder(
height=self.pin_height,
radius=self.diam_outer / 2,
angle=self.slot_span,
centered=(True, True, False)
)
.val()
)
result = (
Cq.Workplane('XY')
.cylinder(
height=length,
radius=self.diam_outer / 2,
centered=(True, True, False),
)
.copyWorkplane(Cq.Workplane('XY'))
.workplane(offset=self.gap)
.polarArray(radius=0, startAngle=self.slot_span, angle=360, count=self.n_pin)
.cutEach(lambda loc: slot.located(loc))
.clean()
.copyWorkplane(Cq.Workplane('XY'))
.cylinder(
height=length,
radius=self.diam_inner / 2,
centered=(True, True, False),
combine="cut"
)
)
return result
@dataclass
class Handle:
"""
Characteristic of a tool handle
This assumes the handle segment material does not have threads. Each segment
attaches to two insertions, which have threads on the inside. A connector
has threads on the outside and mounts two insertions.
Note that all the radial sizes are diameters (in mm).
"""
# Outer and inner radii for the handle usually come in standard sizes
diam: float = 38
diam_inner: float = 33
mount: Optional[Mount] = field(default_factory=lambda: ThreadedMount())
# Internal cavity diameter. This determines the wall thickness of the connector
diam_connector_internal: float = 18.0
# If set to true, do not generate the connections
simplify_geometry: bool = True
# Length for the rim on the female connector
rim_length: float = 5
insertion_length: float = 30
# Amount by which the connector goes into the segment
connector_length: float = 60
def __post_init__(self):
assert self.diam > self.diam_inner, "Material thickness cannot be <= 0"
if self.mount:
assert self.diam_inner > self.mount.diam_insertion_internal(), "Threading radius is too big"
assert self.mount.diam_insertion_internal() >= self.mount.diam_connector_external()
assert self.mount.diam_connector_external() > self.diam_connector_internal, "Internal diameter is too large"
assert self.insertion_length > self.rim_length
def segment(self, length: float):
result = (
Cq.Workplane()
.cylinder(
radius=self.diam / 2,
height=length)
.faces(">Z")
.hole(self.diam_inner)
)
result.faces("<Z").tag("mate1")
result.faces(">Z").tag("mate2")
return result
def insertion(self, holes=[]):
"""
This type of mount is used to connect two handlebar pieces. Each handlebar
piece is a tube which cannot be machined, so the mount connects to the
handle by glue.
Tags:
* lip: Co-planar Mates to the rod
* mate: Mates to the connector
WARNING: A tolerance lower than the defualt (maybe 5e-4) is required for
STL export.
Set `holes` to the heights for drilling holes into the model for resin
to flow out.
"""
result = (
Cq.Workplane('XY')
.cylinder(
radius=self.diam_inner / 2,
height=self.insertion_length - self.rim_length,
centered=[True, True, False])
)
result.faces(">Z").tag("rim")
if self.rim_length > 0:
result = (
result.faces(">Z")
.workplane()
.circle(self.diam / 2)
.extrude(self.rim_length)
.faces(">Z")
.hole(self.mount.diam_insertion_internal())
)
result.faces(">Z").tag("mate")
result.copyWorkplane(Cq.Workplane('XY')).tagPlane("dir", "+X")
if not self.simplify_geometry:
thread = self.mount.internal_thread(self.insertion_length).val()
result = result.union(thread)
for h in holes:
cyl = Cq.Solid.makeCylinder(
radius=2,
height=self.diam * 2,
pnt=(-self.diam, 0, h),
dir=(1, 0, 0))
result = result.cut(cyl)
return result
def connector(self, solid: bool = True):
"""
Tags:
* mate{1,2}: Mates to the connector
WARNING: A tolerance lower than the defualt (maybe 2e-4) is required for
STL export.
"""
result = (
Cq.Workplane('XY')
.cylinder(
radius=self.diam / 2,
height=self.connector_length,
)
)
for (tag, selector) in [("mate1", "<Z"), ("mate2", ">Z")]:
result.faces(selector).tag(tag)
result = (
result
.faces(selector)
.workplane()
.circle(self.mount.diam_connector_external() / 2)
.extrude(self.insertion_length)
)
if not solid:
result = result.faces(">Z").hole(self.diam_connector_internal)
if not self.simplify_geometry:
thread = self.mount.external_thread(self.insertion_length).val()
result = (
result
.union(
thread
.located(Cq.Location((0, 0, -self.connector_length))))
.union(
thread
.rotate((0,0,0), (1,0,0), angleDegrees=180)
.located(Cq.Location((0, 0, self.connector_length))))
)
result.copyWorkplane(Cq.Workplane('XY')).tagPlane("dir", "+X")
return result
def one_side_connector(self, height=None):
if height is None:
height = self.rim_length
result = (
Cq.Workplane('XY')
.cylinder(
radius=self.diam / 2,
height=height,
centered=(True, True, False)
)
)
result.faces(">Z").tag("mate")
result.faces("<Z").tag("base")
result = (
result
.faces(">Z")
.workplane()
.circle(self.mount.diam_connector_external() / 2)
.extrude(self.insertion_length)
)
result.copyWorkplane(Cq.Workplane('XY')).tagPlane("dir", "+X")
if not self.simplify_geometry:
thread = self.mount.external_thread(self.insertion_length).val()
result = (
result
.union(
thread
# Avoids collision in some mating cases
.rotate((0,0,0), (1,0,0), angleDegrees=180)
.located(Cq.Location((0, 0, height + self.insertion_length))))
)
return result
def threaded_core(self, length):
"""
Generates a threaded core for unioning with other components
"""
result = (
Cq.Workplane('XY')
.cylinder(
radius=self.mount.diam_connector_external / 2,
height=length,
centered=(True, True, False),
)
)
result.faces(">Z").tag("mate")
result.faces("<Z").tag("base")
if not self.simplify_geometry:
thread = self.mount.external_thread(length=length).val()
result = (
result
.union(thread)
)
return result
def connector_insertion_assembly(self):
connector_color = Cq.Color(0.8,0.8,0.5,0.3)
insertion_color = Cq.Color(0.7,0.7,0.7,0.3)
result = (
Cq.Assembly()
.add(self.connector(), name="c", color=connector_color)
.add(self.insertion(), name="i1", color=insertion_color)
.add(self.insertion(), name="i2", color=insertion_color)
.constrain("c?mate1", "i1?mate", "Plane")
.constrain("c?mate2", "i2?mate", "Plane")
.constrain("c?dir", "i1?dir", "Axis")
.constrain("c?dir", "i2?dir", "Axis")
.solve()
)
return result
def connector_one_side_insertion_assembly(self):
connector_color = Cq.Color(0.8,0.8,0.5,0.3)
insertion_color = Cq.Color(0.7,0.7,0.7,0.3)
result = (
Cq.Assembly()
.add(self.insertion(), name="i", color=connector_color)
.add(self.one_side_connector(), name="c", color=insertion_color)
.constrain("i?mate", "c?mate", "Plane")
.constrain("c?dir", "i?dir", "Axis")
.solve()
)
return result