File size: 7,558 Bytes
985c397 | 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 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 | # SPDX-License-Identifier: LGPL-2.1-or-later
# ***************************************************************************
# * Copyright (c) 2022 sliptonic <shopinthewoods@gmail.com> *
# * *
# * This program is free software; you can redistribute it and/or modify *
# * it under the terms of the GNU Lesser General Public License (LGPL) *
# * as published by the Free Software Foundation; either version 2 of *
# * the License, or (at your option) any later version. *
# * for detail see the LICENCE text file. *
# * *
# * 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 Library General Public License for more details. *
# * *
# * You should have received a copy of the GNU Library General Public *
# * License along with this program; if not, write to the Free Software *
# * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 *
# * USA *
# * *
# ***************************************************************************
import FreeCAD
import Path
import math
from PySide.QtCore import QT_TRANSLATE_NOOP
__title__ = "CAM Thread Milling generator"
__author__ = "sliptonic (Brad Collette)"
__url__ = "https://www.freecad.org"
__doc__ = "CAM thread milling operation."
if False:
Path.Log.setLevel(Path.Log.Level.DEBUG, Path.Log.thisModule())
Path.Log.trackModule(Path.Log.thisModule())
else:
Path.Log.setLevel(Path.Log.Level.INFO, Path.Log.thisModule())
translate = FreeCAD.Qt.translate
def _comment(path, msg):
"""Nice for debugging to insert markers into generated g-code"""
if False:
path.append(Path.Command("(------- {} -------)".format(msg)))
class _Thread(object):
"""Helper class for dealing with different thread types"""
def __init__(self, cmd, zStart, zFinal, pitch, internal):
self.cmd = cmd
if zStart < zFinal:
self.pitch = pitch
else:
self.pitch = -pitch
self.hPitch = self.pitch / 2
self.zStart = zStart
self.zFinal = zFinal
self.internal = internal
def overshoots(self, z):
"""overshoots(z) ... returns true if adding another half helix goes beyond the thread bounds"""
if self.pitch < 0:
return z + self.hPitch < self.zFinal
return z + self.hPitch > self.zFinal
def adjustX(self, x, dx):
"""adjustX(x, dx) ... move x by dx, the direction depends on the thread settings"""
if self.isG3() == (self.pitch > 0):
return x + dx
return x - dx
def adjustY(self, y, dy):
"""adjustY(y, dy) ... move y by dy, the direction depends on the thread settings"""
if self.isG3():
return y - dy
return y - dy
def isG3(self):
"""isG3() ... returns True if this is a G3 command"""
return self.cmd in ["G3", "G03", "g3", "g03"]
def isUp(self):
"""isUp() ... returns True if the thread goes from the bottom up"""
return self.pitch > 0
def g4Opposite(self):
return "G2" if self.isG3() else "G3"
def g4LeadInOut(self):
if self.internal:
return self.cmd
return self.g4Opposite()
def g4Start2Elevator(self):
return self.g4Opposite()
def generate(center, cmd, zStart, zFinal, pitch, radius, leadInOut, elevator, start):
"""generate(center, cmd, zStart, zFinal, pitch, radius, leadInOut, elevator, start) ... returns the g-code to mill the given internal thread"""
thread = _Thread(cmd, zStart, zFinal, pitch, radius > elevator)
yMin = center.y - radius
yMax = center.y + radius
path = []
# at this point the tool is at a safe heiht (depending on the previous thread), so we can move
# into position first, and then drop to the start height. If there is any material in the way this
# op hasn't been setup properly.
if leadInOut:
_comment(path, "lead-in")
if start is None:
path.append(Path.Command("G0", {"X": center.x, "Y": center.y + elevator}))
path.append(Path.Command("G0", {"Z": thread.zStart}))
else:
path.append(
Path.Command(
thread.g4Start2Elevator(),
{
"X": center.x,
"Y": center.y + elevator,
"Z": thread.zStart,
"I": (center.x - start.x) / 2,
"J": (center.y + elevator - start.y) / 2,
"K": (thread.zStart - start.z) / 2,
},
)
)
path.append(
Path.Command(
thread.g4LeadInOut(),
{"Y": yMax, "J": (yMax - (center.y + elevator)) / 2},
)
)
_comment(path, "lead-in")
else:
if start is None:
path.append(Path.Command("G0", {"X": center.x, "Y": center.y + elevator}))
path.append(Path.Command("G0", {"Z": thread.zStart}))
else:
path.append(
Path.Command("G0", {"X": center.x, "Y": center.y + elevator, "Z": thread.zStart})
)
path.append(Path.Command("G1", {"Y": yMax}))
z = thread.zStart
r = -radius
i = 0
while not Path.Geom.isRoughly(z, thread.zFinal):
if thread.overshoots(z):
break
if 0 == (i & 0x01):
y = yMin
else:
y = yMax
path.append(Path.Command(thread.cmd, {"Y": y, "Z": z + thread.hPitch, "J": r}))
r = -r
i = i + 1
z = z + thread.hPitch
if Path.Geom.isRoughly(z, thread.zFinal):
x = center.x
y = yMin if (i & 0x01) else yMax
else:
n = math.fabs(thread.zFinal - thread.zStart) / thread.hPitch
k = n - int(n)
dy = math.cos(k * math.pi)
dx = math.sin(k * math.pi)
y = thread.adjustY(center.y, r * dy)
x = thread.adjustX(center.x, r * dx)
_comment(path, "finish-thread")
path.append(Path.Command(thread.cmd, {"X": x, "Y": y, "Z": thread.zFinal, "J": r}))
_comment(path, "finish-thread")
a = math.atan2(y - center.y, x - center.x)
dx = math.cos(a) * (radius - elevator)
dy = math.sin(a) * (radius - elevator)
Path.Log.debug("")
Path.Log.debug("a={}: dx={:.2f}, dy={:.2f}".format(a / math.pi * 180, dx, dy))
elevatorX = x - dx
elevatorY = y - dy
Path.Log.debug("({:.2f}, {:.2f}) -> ({:.2f}, {:.2f})".format(x, y, elevatorX, elevatorY))
if leadInOut:
_comment(path, "lead-out")
path.append(
Path.Command(
thread.g4LeadInOut(),
{"X": elevatorX, "Y": elevatorY, "I": -dx / 2, "J": -dy / 2},
)
)
_comment(path, "lead-out")
else:
path.append(Path.Command("G1", {"X": elevatorX, "Y": elevatorY}))
return (path, FreeCAD.Vector(elevatorX, elevatorY, thread.zFinal))
|