File size: 1,704 Bytes
ebc1b3a 5a083bc ebc1b3a 5a083bc ebc1b3a | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 | import math
import FreeCAD as App
import Part
# A chunky spur gear, built from a closed 2D profile and extruded.
teeth = 18
module = 2.2
thickness = 6.0
pitch_r = module * teeth / 2.0
tip_r = pitch_r + module * 0.9
root_r = pitch_r - module * 1.1
step = 2.0 * math.pi / teeth
points = []
for i in range(teeth):
a = i * step
for frac, radius in (
(-0.46, root_r),
(-0.40, root_r),
(-0.35, root_r + (tip_r - root_r) * 0.30),
(-0.28, root_r + (tip_r - root_r) * 0.82),
(-0.20, tip_r),
(0.20, tip_r),
(0.28, root_r + (tip_r - root_r) * 0.82),
(0.35, root_r + (tip_r - root_r) * 0.30),
(0.40, root_r),
(0.46, root_r),
):
angle = a + frac * step
points.append(
App.Vector(math.cos(angle) * radius, math.sin(angle) * radius, 0)
)
points.append(points[0])
profile = Part.Face(Part.makePolygon(points, True))
gear = profile.extrude(App.Vector(0, 0, thickness))
# Centre bore.
gear = gear.cut(
Part.makeCylinder(4.5, thickness + 2.0, App.Vector(0, 0, -1.0))
)
# Five lightening holes.
for i in range(5):
angle = 2.0 * math.pi * i / 5.0 + math.pi / 10.0
centre = App.Vector(
math.cos(angle) * pitch_r * 0.62,
math.sin(angle) * pitch_r * 0.62,
-1.0,
)
gear = gear.cut(Part.makeCylinder(2.8, thickness + 2.0, centre))
plate = Part.show(gear, "GearPlate")
plate.ViewObject.ShapeColor = (0.94, 0.68, 0.32)
hub = Part.makeCylinder(6.8, thickness + 3.0, App.Vector(0, 0, -1.5))
hub = hub.cut(Part.makeCylinder(4.15, thickness + 5.0, App.Vector(0, 0, -2.5)))
hub_obj = Part.show(hub, "Hub")
hub_obj.ViewObject.ShapeColor = (0.27, 0.38, 0.35)
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