# 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 *
[docs]
class Planetary2(Boxes):
"""Balanced force Difference Planetary Gear (not yet working properly)"""
ui_group = "Unstable"
description = """Still has issues. The middle planetary gears set must not have a mashing sun gear as it can't be a proper gear set."""
def __init__(self) -> None:
Boxes.__init__(self)
self.buildArgParser("nema_mount")
self.argparser.add_argument(
"--profile", action="store", type=str, default="GT2_2mm",
choices=pulley.Pulley.getProfiles(),
help="profile of the teeth/belt")
self.argparser.add_argument(
"--sunteeth", action="store", type=int, default=20,
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(
"--maxplanets", action="store", type=int, default=0,
help="limit the number of planets (0 for as much as fit)")
self.argparser.add_argument(
"--deltateeth", action="store", type=int, default=1,
help="enable secondary ring with given delta to the ring gear")
self.argparser.add_argument(
"--modulus", action="store", type=float, default=1.0,
help="modulus of the teeth in mm")
self.argparser.add_argument(
"--shaft", action="store", type=float, default=6.,
help="diameter of the shaft")
self.argparser.add_argument(
"--screw1", action="store", type=float, default=2.4,
help="diameter of lower part of the screw hole")
self.argparser.add_argument(
"--screw2", action="store", type=float, default=4.,
help="diameter of upper part of the screw hole")
self.argparser.add_argument(
"--pinsize", action="store", type=float, default=3.1,
help="diameter of alignment pins")
# self.argparser.add_argument(
# "--stages", action="store", type=int, default=4,
# help="number of stages in the gear reduction")
def pins(self, r, rh, nr=0, angle=0.0):
self.moveTo(0, 0, angle)
if nr < 8:
ang = 20 + 10 * nr
else:
ang = 15 + 10 * (nr-8)
ang = 180 - ang
for a in (0, ang, -ang):
self.moveTo(0, 0, a)
self.hole(r, 0, rh)
self.moveTo(0, 0, -a)
def render(self):
ringteeth = self.sunteeth + 2 * self.planetteeth
t = self.thickness
spoke_width = 4 * t
pinsize = self.pinsize / 2.
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)
planets = int(math.pi / (math.asin(float(self.planetteeth + 2) / (self.planetteeth + self.sunteeth))))
if self.maxplanets:
planets = min(self.maxplanets, planets)
# Make sure the teeth mash
ta = self.sunteeth + ringteeth
# There are sunteeth+ringteeth mashing positions for the planets
planetpositions = [round(i * ta / planets) * 360 / ta for i in range(planets)]
secondary_offsets = [((pos % (360. / (ringteeth - self.deltateeth))) -
(pos % (360. / ringteeth)) * ringteeth / self.planetteeth)
for pos in planetpositions]
ratio = (1 + (ringteeth / self.sunteeth)) * (-ringteeth/self.deltateeth)
# XXX make configurable?
profile_shift = 20
pressure_angle = 20
screw = self.screw1 / 2
# output
# XXX simple guess
belt = self.profile
pulleyteeth = int((size3-2*t) * math.pi / pulley.Pulley.spacing[belt][1])
numplanets = planets
deltamodulus = self.modulus * ringteeth / (ringteeth - self.deltateeth)
def holes(r):
def h():
self.hole(2*t, 2*t, r)
self.hole(size3-2*t, 2*t, r)
self.hole(2*t, size3-2*t, r)
self.hole(size3-2*t, size3-2*t, r)
return h
def planets():
self.moveTo(size3/2, size3/2)
for angle in planetpositions:
angle += 180 # compensate for 3 position in callback
self.moveTo(0, 0, angle)
self.hole((pitch1+pitch2), 0, size2/2)
self.moveTo(0, 0, -angle)
# Base
self.rectangularWall(size3, size3, callback=[
lambda: self.NEMA(self.nema_mount, size3 / 2, size3 / 2),
holes(screw), planets],
move="up")
def gear():
self.moveTo(size3 / 2, size3 / 2)
self.gears(teeth=ringteeth, dimension=self.modulus,
angle=pressure_angle, internal_ring=True,
spoke_width=spoke_width, teeth_only=True,
profile_shift=profile_shift, move="up")
# Lower primary ring gear
self.rectangularWall(size3, size3, callback=[gear, holes(screw)], move="up")
tl = 0.5*size3*(2**0.5-1)*2**0.5
screw = self.screw2 / 2
self.rectangularTriangle(tl, tl, num=8, callback=[
None, lambda:self.hole(2*t, 2*t, screw)], move='up')
# Secondary ring gears
def ring():
self.gears(teeth=ringteeth - self.deltateeth,
dimension=deltamodulus,
angle=pressure_angle, internal_ring=True,
spoke_width=spoke_width, teeth_only=True,
profile_shift=profile_shift)
for i in range(3):
self.hole((size3-6*t)/2+0.5*pinsize, 0, pinsize)
self.moveTo(0, 0, 120)
self.pulley(pulleyteeth, belt, callback=ring, move="up")
self.pulley(pulleyteeth, belt, callback=ring, move="up")
# Upper primary ring gear
self.rectangularWall(size3, size3, callback=[gear, holes(screw)], move="up")
# top cover plate
self.rectangularWall(size3, size3, callback=[holes(screw)], move="up")
# Sun gear
def sunpins():
self.hole(0.5*self.shaft+1.5*pinsize ,0, pinsize)
self.hole(-0.5*self.shaft-1.5*pinsize ,0, pinsize)
self.partsMatrix(4, 4, 'up', self.gears, teeth=self.sunteeth,
dimension=self.modulus, callback=sunpins,
angle=pressure_angle, mount_hole=self.shaft,
profile_shift=profile_shift)
# Planets
for i in range(numplanets):
with self.saved_context():
self.gears(teeth=self.planetteeth, dimension=self.modulus,
angle=pressure_angle,
callback=lambda:self.pins(0.25*size2, pinsize, i),
profile_shift=profile_shift, move="right")
for j in range(2):
self.gears(teeth=self.planetteeth, dimension=self.modulus,
angle=pressure_angle,
callback=lambda:self.pins(0.25*size2, pinsize, i,
secondary_offsets[i]),
profile_shift=profile_shift, move="right")
self.gears(teeth=self.planetteeth, dimension=self.modulus,
angle=pressure_angle,
callback=lambda:self.pins(0.25*size2, pinsize, i),
profile_shift=profile_shift, move="right")
self.gears(teeth=self.planetteeth, dimension=self.modulus,
angle=pressure_angle,
profile_shift=profile_shift, move="up only")
self.text("1:%.1f" % abs(ratio))
