feat: Bent elbow joint

This commit is contained in:
Leni Aniva 2024-07-18 14:03:01 -07:00
parent 9795f7b714
commit 4c5985fa08
Signed by: aniva
GPG Key ID: 4D9B1C8D10EA4C50
3 changed files with 80 additions and 46 deletions

View File

@ -313,6 +313,9 @@ class Beam:
class DiskJoint(Model):
"""
Sandwiched disk joint for the wrist and elbow
We embed a spring inside the joint, with one leg in the disk and one leg in
the housing. This provides torsion resistance.
"""
spring: TorsionSpring = field(default_factory=lambda: TorsionSpring(
radius=9 / 2,
@ -328,14 +331,15 @@ class DiskJoint(Model):
housing_thickness: float = 4.0
disk_thickness: float = 7.0
# Gap between disk and the housing
#disk_thickness_gap: float = 0.1
# Amount by which the wall carves in
wall_inset: float = 2.0
# Height of the spring hole; if you make it too short the spring can't enter
spring_tail_hole_height: float = 2.0
# Spring angle at 0 degrees of movement
spring_angle_at_0: float = 60.0
spring_slot_offset: float = 15.0
wall_inset: float = 2.0
spring_angle_at_0: float = 90.0
spring_slot_offset: float = 5.0
# Angular span of movement
movement_angle: float = 120.0
@ -348,10 +352,11 @@ class DiskJoint(Model):
def __post_init__(self):
super().__init__(name="disk-joint")
assert self.housing_thickness > self.wall_inset
assert self.radius_housing > self.radius_disk
assert self.radius_disk > self.radius_axle
assert self.radius_housing > self.radius_disk > self.radius_axle
assert self.spring.height < self.housing_thickness + self.disk_thickness
assert self.housing_upper_carve_offset > 0
assert self.spring_tail_hole_height > self.spring.thickness
@property
def neutral_movement_angle(self) -> Optional[float]:
@ -363,6 +368,12 @@ class DiskJoint(Model):
@property
def total_thickness(self) -> float:
return self.housing_thickness * 2 + self.disk_thickness
@property
def disk_bot_thickness(self) -> float:
"""
Pads the bottom of the disk up to spring height
"""
return max(0, self.disk_thickness + self.spring.thickness - self.spring.height)
@property
def opening_span(self) -> float:
@ -373,7 +384,7 @@ class DiskJoint(Model):
"""
Distance between the spring track and the outside of the upper housing
"""
return self.housing_thickness + self.disk_thickness - self.spring.height
return self.spring_tail_hole_height + (self.disk_thickness - self.disk_bot_thickness) - self.spring.height
@property
def housing_upper_dz(self) -> float:
@ -387,9 +398,9 @@ class DiskJoint(Model):
Cq.Solid.makeBox(
length=self.spring.tail_length,
width=self.spring.thickness,
height=self.disk_thickness,
height=self.spring.height-self.disk_bot_thickness,
)
.located(Cq.Location((0, self.spring.radius_inner, 0)))
.located(Cq.Location((0, self.spring.radius_inner, self.disk_bot_thickness)))
.rotate((0, 0, 0), (0, 0, 1), self.spring_slot_offset)
)
@ -427,6 +438,7 @@ class DiskJoint(Model):
theta = math.radians(self.spring_slot_offset)
plane.tagPlane("dir", direction=(math.cos(theta), math.sin(theta), 0))
plane.workplane(offset=self.disk_thickness).tagPlane("mate_top")
plane.workplane(offset=self.disk_bot_thickness).tagPlane("mate_spring")
result.copyWorkplane(Cq.Workplane('YX')).tagPlane("mate_bot")
return result
@ -474,11 +486,11 @@ class DiskJoint(Model):
carve = (
Cq.Solid.makeCylinder(
radius=self.spring.radius,
height=self.housing_thickness
height=self.spring_tail_hole_height,
).fuse(Cq.Solid.makeBox(
length=self.spring.tail_length,
width=self.spring.thickness,
height=self.housing_thickness
height=self.spring_tail_hole_height,
).located(Cq.Location((0, -self.spring.radius, 0))))
).rotate((0, 0, 0), (0, 0, 1), carve_angle)
result = (
@ -515,6 +527,7 @@ class DiskJoint(Model):
result = (
result
.union(wall, tol=TOL)
#.cut(carve)
.cut(carve.located(Cq.Location((0, 0, -self.housing_upper_carve_offset))))
)
return result.clean()
@ -541,7 +554,7 @@ class DiskJoint(Model):
.constrain(f"{housing_lower}?dirX", f"{housing_upper}?dirX", "Axis", param=0)
.constrain(f"{housing_upper}?dir", f"{spring_name}?dir_top", "Axis", param=0)
.constrain(f"{spring_name}?dir_bot", f"{disk}?dir", "Axis", param=0)
.constrain(f"{disk}?mate_bot", f"{spring_name}?bot", "Plane", param=0)
.constrain(f"{disk}?mate_spring", f"{spring_name}?bot", "Plane")
#.constrain(f"{housing_lower}?dirX", f"{housing_upper}?dir", "Axis", param=0)
#.constrain(f"{housing_lower}?dirX", f"{disk}?dir", "Axis", param=angle)
#.constrain(f"{housing_lower}?dirY", f"{disk}?dir", "Axis", param=angle - 90)
@ -608,13 +621,26 @@ class ElbowJoint(Model):
material: Material = Material.RESIN_TRANSPERENT
angle_neutral: float = 0.0
angle_neutral: float = 30.0
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 - self.lip_thickness / 2
def parent_arm_loc(self) -> Cq.Location:
"""
2d Location of the centre of the arm surface on the parent side, assuming
axle is at position 0, and parent direction is -X
"""
return Cq.Location.from2d(-self.parent_arm_radius, 0, 0)
def child_arm_loc(self) -> Cq.Location:
"""
2d Location of the centre of the arm surface on the child side, assuming
axle is at position 0, and parent direction is -X
"""
return Cq.Location.rot2d(self.angle_neutral) * Cq.Location.from2d(self.child_arm_radius, 0, 180)
def lip(self) -> Cq.Workplane:
holes = [
h
@ -649,8 +675,9 @@ class ElbowJoint(Model):
Cq.Location((0, 0, 0), (0, 1, 0), 90)
)
loc_disk = flip_x * flip_z * Cq.Location((-self.child_arm_radius, 0, -dz), (0, 0, 1), angle)
loc_cut_rel = Cq.Location((0, self.disk_joint.spring.radius_inner, -self.disk_joint.disk_bot_thickness))
disk_cut = self.disk_joint._disk_cut().located(
loc_lip.inverse * Cq.Location((0, self.disk_joint.spring.radius_inner, 0)) * loc_disk)
loc_lip.inverse * loc_cut_rel * loc_disk)
result = (
Cq.Assembly()
.add(self.lip().cut(disk_cut), name="lip", loc=loc_lip)

View File

@ -53,6 +53,7 @@ class WingProfile(Model):
movement_angle=55,
),
hole_diam=6.0,
angle_neutral=15.0,
))
# Distance between the two spacers on the elbow, halved
elbow_h2: float = 5.0
@ -70,6 +71,7 @@ class WingProfile(Model):
child_arm_radius=23.0,
parent_arm_radius=30.0,
hole_diam=4.0,
angle_neutral=30.0,
))
# Distance between the two spacers on the elbow, halved
wrist_h2: float = 5.0
@ -86,6 +88,8 @@ class WingProfile(Model):
elbow_height: float
wrist_bot_loc: Cq.Location
wrist_height: float
elbow_rotate: float = -5
wrist_rotate: float = 30.0
flip: bool = False
@ -94,6 +98,8 @@ class WingProfile(Model):
self.elbow_top_loc = self.elbow_bot_loc * Cq.Location.from2d(0, self.elbow_height)
self.wrist_top_loc = self.wrist_bot_loc * Cq.Location.from2d(0, self.wrist_height)
self.elbow_axle_loc = self.elbow_bot_loc * Cq.Location.from2d(0, self.elbow_height / 2)
self.wrist_axle_loc = self.wrist_bot_loc * Cq.Location.from2d(0, self.wrist_height / 2)
self.shoulder_joint.angle_neutral = -self.shoulder_angle_neutral - self.shoulder_angle_bias
@ -439,13 +445,12 @@ class WingProfile(Model):
("shoulder_top", Cq.Location.from2d(0, h + shoulder_h, 270)),
]
h = self.elbow_height / 2
loc_elbow = Cq.Location.rot2d(self.elbow_rotate) * self.elbow_joint.parent_arm_loc()
tags_elbow = [
("elbow_bot", self.elbow_bot_loc * Cq.Location.from2d(
-self.elbow_joint.parent_arm_radius,
h - self.elbow_h2)),
("elbow_top", self.elbow_bot_loc * Cq.Location.from2d(
-self.elbow_joint.parent_arm_radius,
h + self.elbow_h2)),
("elbow_bot", self.elbow_axle_loc * loc_elbow *\
Cq.Location.from2d(0, -self.elbow_h2)),
("elbow_top", self.elbow_axle_loc * loc_elbow *\
Cq.Location.from2d(0, self.elbow_h2)),
]
profile = self.profile_s1()
tags = tags_shoulder + tags_elbow
@ -507,24 +512,20 @@ class WingProfile(Model):
return profile
def surface_s2(self, front: bool = True) -> Cq.Workplane:
h = self.elbow_height / 2
loc_elbow = Cq.Location.rot2d(self.elbow_rotate) * self.elbow_joint.child_arm_loc()
tags_elbow = [
("elbow_bot", self.elbow_bot_loc * Cq.Location.from2d(
self.elbow_joint.child_arm_radius,
h - self.elbow_h2,
180)),
("elbow_top", self.elbow_bot_loc * Cq.Location.from2d(
self.elbow_joint.child_arm_radius,
h + self.elbow_h2,
180)),
("elbow_bot", self.elbow_axle_loc * loc_elbow *\
Cq.Location.from2d(0, self.elbow_h2)),
("elbow_top", self.elbow_axle_loc * loc_elbow *\
Cq.Location.from2d(0, -self.elbow_h2)),
]
h = self.wrist_height / 2
loc_wrist = Cq.Location.rot2d(self.wrist_rotate) * self.wrist_joint.parent_arm_loc().flip_y()
tags_wrist = [
("wrist_bot", self.wrist_bot_loc * Cq.Location.from2d(
-self.wrist_joint.parent_arm_radius,
h - self.wrist_h2)),
("wrist_top", self.wrist_bot_loc * Cq.Location.from2d(
-self.wrist_joint.parent_arm_radius,
h + self.wrist_h2)),
("wrist_bot", self.wrist_axle_loc * loc_wrist *\
Cq.Location.from2d(0, -self.wrist_h2)),
("wrist_top", self.wrist_axle_loc * loc_wrist *\
Cq.Location.from2d(0, self.wrist_h2)),
]
profile = self.profile_s2()
tags = tags_elbow + tags_wrist
@ -564,7 +565,7 @@ class WingProfile(Model):
o.generate(),
point_tag=t,
flipped=is_top == is_parent,
#rotate=True,
#rotate=not is_parent,
)
return result.solve()
@ -579,15 +580,12 @@ class WingProfile(Model):
def surface_s3(self,
front: bool = True) -> Cq.Workplane:
h = self.wrist_height / 2
loc_wrist = Cq.Location.rot2d(self.wrist_rotate) * self.wrist_joint.child_arm_loc().flip_y()
tags = [
("wrist_bot", self.wrist_bot_loc * Cq.Location.from2d(
self.wrist_joint.child_arm_radius,
h - self.wrist_h2,
180)),
("wrist_top", self.wrist_bot_loc * Cq.Location.from2d(
self.wrist_joint.child_arm_radius,
h + self.wrist_h2,
180)),
("wrist_bot", self.wrist_axle_loc * loc_wrist *\
Cq.Location.from2d(0, self.wrist_h2)),
("wrist_top", self.wrist_axle_loc * loc_wrist *\
Cq.Location.from2d(0, -self.wrist_h2)),
]
profile = self.profile_s3()
return extrude_with_markers(profile, self.panel_thickness, tags, reverse=front)

View File

@ -82,6 +82,15 @@ def with_angle_2d(self: Cq.Location, angle: float) -> Tuple[float, float]:
return Cq.Location.from2d(x, y, angle)
Cq.Location.with_angle_2d = with_angle_2d
def flip_x(self: Cq.Location) -> Cq.Location:
(x, y), a = self.to2d()
return Cq.Location.from2d(-x, y, 90 - a)
Cq.Location.flip_x = flip_x
def flip_y(self: Cq.Location) -> Cq.Location:
(x, y), a = self.to2d()
return Cq.Location.from2d(x, -y, -a)
Cq.Location.flip_y = flip_y
### Tags
def tagPoint(self, tag: str):