boxespy/boxes/generators/planetary.py

93 lines
3.7 KiB
Python

#!/usr/bin/env python3
# Copyright (C) 2013-2016 Florian Festi
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
from boxes import *
import math
class Planetary(Boxes):
"""Gearbox with multiple identical stages"""
def __init__(self):
Boxes.__init__(self)
self.argparser.add_argument(
"--sunteeth", action="store", type=int, default=8,
help="number of teeth on sun gear")
self.argparser.add_argument(
"--planetteeth", action="store", type=int, default=20,
help="number of teeth on planets")
self.argparser.add_argument(
"--modulus", action="store", type=float, default=3,
help="modulus of the theeth in mm")
self.argparser.add_argument(
"--shaft", action="store", type=float, default=6.,
help="diameter of the shaft")
#self.argparser.add_argument(
# "--stages", action="store", type=int, default=4,
# help="number of stages in the gear reduction")
def render(self):
# Initialize canvas
self.open()
ringteeth = self.sunteeth+2*self.planetteeth
spoke_width = 3*self.shaft
pitch1, size1, xxx = self.gears.sizes(teeth=self.sunteeth,
dimension=self.modulus)
pitch2, size2, xxx = self.gears.sizes(teeth=self.planetteeth,
dimension=self.modulus)
pitch3, size3, xxx = self.gears.sizes(
teeth=ringteeth, internal_ring=True, spoke_width=spoke_width,
dimension=self.modulus)
t = self.thickness
planets = int(math.pi//math.asin((self.planetteeth+2)/(self.planetteeth+self.sunteeth)))
# Make sure the teeth mash
ta = self.sunteeth+ringteeth
# There are sunteeth+ringteeth mashing positions for the planets
if ta % planets:
planetpositions = [round(i*ta/planets)*360/ta for i in range(planets)]
else:
planetpositions = planets
# XXX make configurable?
profile_shift = 20
pressure_angle = 20
self.parts.disc(size3, lambda:self.hole(0,0,self.shaft/2), move="up")
self.gears(teeth=ringteeth, dimension=self.modulus,
angle=pressure_angle, internal_ring=True,
spoke_width=spoke_width, mount_hole=self.shaft,
profile_shift=profile_shift, move="up")
self.gears.gearCarrier(pitch1+pitch2, spoke_width, planetpositions,
2*spoke_width, self.shaft/2, move="up")
self.gears(teeth=self.sunteeth, dimension=self.modulus,
angle=pressure_angle,
mount_hole=self.shaft, profile_shift=profile_shift, move="up")
for i in range(planets):
self.gears(teeth=self.planetteeth, dimension=self.modulus,
angle=pressure_angle,
mount_hole=self.shaft, profile_shift=profile_shift, move="up")
self.close()
def main():
b = Box()
b.parseArgs()
b.render()
if __name__ == '__main__':
main()