Files
create/src/Mod/Path/PathScripts/PathThreadMilling.py

556 lines
21 KiB
Python

# -*- coding: utf-8 -*-
# ***************************************************************************
# * Copyright (c) 2019 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 *
# * *
# ***************************************************************************
from __future__ import print_function
import FreeCAD
import Path
import PathScripts.PathCircularHoleBase as PathCircularHoleBase
import PathScripts.PathGeom as PathGeom
import PathScripts.PathLog as PathLog
import PathScripts.PathOp as PathOp
import math
from PySide.QtCore import QT_TRANSLATE_NOOP
__title__ = "Path Thread Milling Operation"
__author__ = "sliptonic (Brad Collette)"
__url__ = "http://www.freecadweb.org"
__doc__ = "Path thread milling operation."
# math.sqrt(3)/2 ... 60deg triangle height
SQRT_3_DIVIDED_BY_2 = 0.8660254037844386
if True:
PathLog.setLevel(PathLog.Level.DEBUG, PathLog.thisModule())
PathLog.trackModule(PathLog.thisModule())
else:
PathLog.setLevel(PathLog.Level.INFO, PathLog.thisModule())
translate = FreeCAD.Qt.translate
def threadRadii(internal, majorDia, minorDia, toolDia, toolCrest):
"""threadRadii(majorDia, minorDia, toolDia, toolCrest) ... returns the minimum and maximum radius for thread."""
PathLog.track(majorDia, minorDia, toolDia, toolCrest)
if toolCrest is None:
toolCrest = 0.0
# As it turns out metric and imperial standard threads follow the same rules.
# The determining factor is the height of the full 60 degree triangle H.
# - The minor diameter is 1/4 * H smaller than the pitch diameter.
# - The major diameter is 3/8 * H bigger than the pitch diameter
# Since we already have the outer diameter it's simpler to just add 1/8 * H
# to get the outer tip of the thread.
H = ((majorDia - minorDia) / 2.0) * 1.6 # (D - d)/2 = 5/8 * H
if internal:
# mill inside out
outerTip = majorDia / 2.0 + H / 8.0
# Compensate for the crest of the tool
toolTip = outerTip - toolCrest * SQRT_3_DIVIDED_BY_2
return ((minorDia - toolDia) / 2.0, toolTip - toolDia / 2.0)
# mill outside in
innerTip = minorDia / 2.0 - H / 4.0
# Compensate for the crest of the tool
toolTip = innerTip - toolCrest * SQRT_3_DIVIDED_BY_2
return ((majorDia + toolDia) / 2.0, toolTip + toolDia / 2.0)
def threadPasses(count, radii, internal, majorDia, minorDia, toolDia, toolCrest):
PathLog.track(count, radii, internal, majorDia, minorDia, toolDia, toolCrest)
minor, major = radii(internal, majorDia, minorDia, toolDia, toolCrest)
dr = float(major - minor) / count
if internal:
return [minor + dr * (i + 1) for i in range(count)]
return [major - dr * (i + 1) for i in range(count)]
def elevatorRadius(obj, center, internal, tool):
'''elevatorLocation(obj, center, internal, tool) ... return suitable location for the tool elevator'''
if internal:
dy = float(obj.MinorDiameter - tool.Diameter) / 2 - 1
if dy < 0:
if (obj.MinorDiameter < tool.Diameter):
PathLog.error("The selected tool is too big (d={}) for milling a thread with minor diameter D={}".format(tool.Diameter, obj.MinorDiameter))
dy = 0
else:
dy = float(obj.MajorDiameter + tool.Diameter) / 2 + 1
return dy
def comment(path, msg):
if True:
path.append(Path.Command("(------- {} -------)".format(msg)))
class _ThreadInternal(object):
"""Helper class for dealing with different thread types"""
def __init__(self, cmd, zStart, zFinal, pitch):
self.cmd = cmd
if zStart < zFinal:
self.pitch = pitch
else:
self.pitch = -pitch
self.hPitch = self.pitch / 2
self.zStart = zStart
self.zFinal = zFinal
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 threadCommands(center, cmd, zStart, zFinal, pitch, radius, leadInOut, elevator):
"""threadCommands(center, cmd, zStart, zFinal, pitch, radius) ... returns the g-code to mill the given internal thread"""
thread = _ThreadInternal(cmd, zStart, zFinal, pitch)
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.
path.append(Path.Command("G0", {"X": center.x, "Y": center.y + elevator}))
path.append(Path.Command("G0", {"Z": thread.zStart}))
if leadInOut:
comment(path, 'lead-in')
path.append(Path.Command(thread.cmd, {"Y": yMax, "J": (yMax - (center.y + elevator)) / 2}))
comment(path, 'lead-in')
else:
path.append(Path.Command("G1", {"Y": yMax}))
z = thread.zStart
r = -radius
i = 0
while not PathGeom.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 PathGeom.isRoughly(z, thread.zFinal):
x = center.x
y = yMin if 0 == (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) * elevator
dy = math.sin(a) * elevator
if leadInOut:
comment(path, 'lead-out')
path.append(
Path.Command(
thread.cmd,
{"X": center.x + dx, "Y": center.y + dy, "I": dx / 2, "J": dy / 2},
)
)
comment(path, 'lead-out')
path.append(Path.Command("G1", {"X": center.x + dx, "Y": center.y - dy}))
return path
class ObjectThreadMilling(PathCircularHoleBase.ObjectOp):
"""Proxy object for thread milling operation."""
LeftHand = "LeftHand"
RightHand = "RightHand"
ThreadTypeCustomExternal = "CustomExternal"
ThreadTypeCustomInternal = "CustomInternal"
ThreadTypeImperialExternal2A = "ImperialExternal2A"
ThreadTypeImperialExternal3A = "ImperialExternal3A"
ThreadTypeImperialInternal2B = "ImperialInternal2B"
ThreadTypeImperialInternal3B = "ImperialInternal3B"
ThreadTypeMetricExternal4G6G = "MetricExternal4G6G"
ThreadTypeMetricExternal6G = "MetricExternal6G"
ThreadTypeMetricInternal6H = "MetricInternal6H"
DirectionClimb = "Climb"
DirectionConventional = "Conventional"
ThreadOrientations = [LeftHand, RightHand]
ThreadTypeData = {
ThreadTypeImperialExternal2A : 'imperial-external-2A.csv',
ThreadTypeImperialExternal3A : 'imperial-external-3A.csv',
ThreadTypeImperialInternal2B : 'imperial-internal-2B.csv',
ThreadTypeImperialInternal3B : 'imperial-internal-3B.csv',
ThreadTypeMetricExternal4G6G : 'metric-external-4G6G.csv',
ThreadTypeMetricExternal6G : 'metric-external-6G.csv',
ThreadTypeMetricInternal6H : 'metric-internal-6H.csv',
}
ThreadTypesExternal = [
ThreadTypeCustomExternal,
ThreadTypeImperialExternal2A,
ThreadTypeImperialExternal3A,
ThreadTypeMetricExternal4G6G,
ThreadTypeMetricExternal6G,
]
ThreadTypesInternal = [
ThreadTypeCustomInternal,
ThreadTypeImperialInternal2B,
ThreadTypeImperialInternal3B,
ThreadTypeMetricInternal6H,
]
ThreadTypesImperial = [
ThreadTypeImperialExternal2A,
ThreadTypeImperialExternal3A,
ThreadTypeImperialInternal2B,
ThreadTypeImperialInternal3B,
]
ThreadTypesMetric = [
ThreadTypeMetricExternal4G6G,
ThreadTypeMetricExternal6G,
ThreadTypeMetricInternal6H,
]
ThreadTypes = ThreadTypesInternal + ThreadTypesExternal
Directions = [DirectionClimb, DirectionConventional]
@classmethod
def propertyEnumerations(self, dataType="data"):
"""helixOpPropertyEnumerations(dataType="data")... return property enumeration lists of specified dataType.
Args:
dataType = 'data', 'raw', 'translated'
Notes:
'data' is list of internal string literals used in code
'raw' is list of (translated_text, data_string) tuples
'translated' is list of translated string literals
"""
PathLog.track()
# Enumeration lists for App::PropertyEnumeration properties
enums = {
"ThreadType": [
(translate("Path_ThreadMilling", "Custom External"), ObjectThreadMilling.ThreadTypeCustomExternal),
(translate("Path_ThreadMilling", "Custom Internal"), ObjectThreadMilling.ThreadTypeCustomInternal),
(translate("Path_ThreadMilling", "Imperial External (2A)"), ObjectThreadMilling.ThreadTypeImperialExternal2A),
(translate("Path_ThreadMilling", "Imperial External (3A)"), ObjectThreadMilling.ThreadTypeImperialExternal3A),
(translate("Path_ThreadMilling", "Imperial Internal (2B)"), ObjectThreadMilling.ThreadTypeImperialInternal2B),
(translate("Path_ThreadMilling", "Imperial Internal (3B)"), ObjectThreadMilling.ThreadTypeImperialInternal3B),
(translate("Path_ThreadMilling", "Metric External (4G6G)"), ObjectThreadMilling.ThreadTypeMetricExternal4G6G),
(translate("Path_ThreadMilling", "Metric External (6G)"), ObjectThreadMilling.ThreadTypeMetricExternal6G),
(translate("Path_ThreadMilling", "Metric Internal (6H)"), ObjectThreadMilling.ThreadTypeMetricInternal6H),
],
"ThreadOrientation": [
(translate("Path_ThreadMilling", "LeftHand"), ObjectThreadMilling.LeftHand),
(translate("Path_ThreadMilling", "RightHand"), ObjectThreadMilling.RightHand),
],
"Direction": [
(translate("Path_ThreadMilling", "Climb"), ObjectThreadMilling.DirectionClimb),
(translate("Path_ThreadMilling", "Conventional"), ObjectThreadMilling.DirectionConventional),
],
}
if dataType == "raw":
return enums
data = list()
idx = 0 if dataType == "translated" else 1
PathLog.debug(enums)
for k, v in enumerate(enums):
data.append((v, [tup[idx] for tup in enums[v]]))
PathLog.debug(data)
return data
def circularHoleFeatures(self, obj):
PathLog.track()
return PathOp.FeatureBaseGeometry
def initCircularHoleOperation(self, obj):
PathLog.track()
obj.addProperty(
"App::PropertyEnumeration",
"ThreadOrientation",
"Thread",
QT_TRANSLATE_NOOP("App::Property", "Set thread orientation"),
)
# obj.ThreadOrientation = self.ThreadOrientations
obj.addProperty(
"App::PropertyEnumeration",
"ThreadType",
"Thread",
QT_TRANSLATE_NOOP("App::Property", "Currently only internal"),
)
# obj.ThreadType = self.ThreadTypes
obj.addProperty(
"App::PropertyString",
"ThreadName",
"Thread",
QT_TRANSLATE_NOOP(
"App::Property", "Defines which standard thread was chosen"
),
)
obj.addProperty(
"App::PropertyLength",
"MajorDiameter",
"Thread",
QT_TRANSLATE_NOOP("App::Property", "Set thread's major diameter"),
)
obj.addProperty(
"App::PropertyLength",
"MinorDiameter",
"Thread",
QT_TRANSLATE_NOOP("App::Property", "Set thread's minor diameter"),
)
obj.addProperty(
"App::PropertyLength",
"Pitch",
"Thread",
QT_TRANSLATE_NOOP(
"App::Property", "Set thread's pitch - used for metric threads"
),
)
obj.addProperty(
"App::PropertyInteger",
"TPI",
"Thread",
QT_TRANSLATE_NOOP(
"App::Property",
"Set thread's TPI (turns per inch) - used for imperial threads",
),
)
obj.addProperty(
"App::PropertyInteger",
"ThreadFit",
"Thread",
QT_TRANSLATE_NOOP(
"App::Property", "Set how many passes are used to cut the thread"
),
)
obj.addProperty(
"App::PropertyInteger",
"Passes",
"Operation",
QT_TRANSLATE_NOOP(
"App::Property", "Set how many passes are used to cut the thread"
),
)
obj.addProperty(
"App::PropertyEnumeration",
"Direction",
"Operation",
QT_TRANSLATE_NOOP("App::Property", "Direction of thread cutting operation"),
)
obj.addProperty(
"App::PropertyBool",
"LeadInOut",
"Operation",
QT_TRANSLATE_NOOP(
"App::Property",
"Set to True to get lead in and lead out arcs at the start and end of the thread cut",
),
)
obj.addProperty(
"App::PropertyLink",
"ClearanceOp",
"Operation",
QT_TRANSLATE_NOOP(
"App::Property", "Operation to clear the inside of the thread"
),
)
for n in self.propertyEnumerations():
setattr(obj, n[0], n[1])
def _isThreadInternal(self, obj):
return obj.ThreadType in self.ThreadTypesInternal
def _threadSetupInternal(self, obj):
PathLog.track()
# the thing to remember is that Climb, for an internal thread must always be G3
if obj.Direction == self.DirectionClimb:
if obj.ThreadOrientation == self.RightHand:
return ("G3", obj.FinalDepth.Value, obj.StartDepth.Value)
return ("G3", obj.StartDepth.Value, obj.FinalDepth.Value)
if obj.ThreadOrientation == self.RightHand:
return ("G2", obj.StartDepth.Value, obj.FinalDepth.Value)
return ("G2", obj.FinalDepth.Value, obj.StartDepth.Value)
def threadSetup(self, obj):
PathLog.track()
cmd, zbegin, zend = self._threadSetupInternal(obj)
if obj.ThreadType in self.ThreadTypesInternal:
return (cmd, zbegin, zend)
# need to reverse direction for external threads
if cmd == 'G2':
return ('G3', zbegin, zend)
return ('G2', zbegin, zend)
def threadPassRadii(self, obj):
PathLog.track(obj.Label)
rMajor = (obj.MajorDiameter.Value - self.tool.Diameter) / 2.0
rMinor = (obj.MinorDiameter.Value - self.tool.Diameter) / 2.0
if obj.Passes < 1:
obj.Passes = 1
rPass = (rMajor - rMinor) / obj.Passes
passes = [rMajor]
for i in range(1, obj.Passes):
passes.append(rMajor - rPass * i)
return list(reversed(passes))
def executeThreadMill(self, obj, loc, gcode, zStart, zFinal, pitch):
PathLog.track(obj.Label, loc, gcode, zStart, zFinal, pitch)
elevator = elevatorRadius(obj, loc, self._isThreadInternal(obj), self.tool)
self.commandlist.append(
Path.Command("G0", {"Z": obj.ClearanceHeight.Value, "F": self.vertRapid})
)
for radius in threadPasses(
obj.Passes,
threadRadii,
self._isThreadInternal(obj),
obj.MajorDiameter.Value,
obj.MinorDiameter.Value,
float(self.tool.Diameter),
float(self.tool.Crest),
):
commands = threadCommands(loc, gcode, zStart, zFinal, pitch, radius, obj.LeadInOut, elevator)
for cmd in commands:
p = cmd.Parameters
if cmd.Name in ["G0"]:
p.update({"F": self.vertRapid})
if cmd.Name in ["G1", "G2", "G3"]:
p.update({"F": self.horizFeed})
cmd.Parameters = p
self.commandlist.extend(commands)
self.commandlist.append(
Path.Command("G0", {"Z": obj.ClearanceHeight.Value, "F": self.vertRapid})
)
def circularHoleExecute(self, obj, holes):
PathLog.track()
if self.isToolSupported(obj, self.tool):
self.commandlist.append(Path.Command("(Begin Thread Milling)"))
(cmd, zStart, zFinal) = self.threadSetup(obj)
pitch = obj.Pitch.Value
if obj.TPI > 0:
pitch = 25.4 / obj.TPI
if pitch <= 0:
PathLog.error("Cannot create thread with pitch {}".format(pitch))
return
# rapid to clearance height
for loc in holes:
self.executeThreadMill(
obj,
FreeCAD.Vector(loc["x"], loc["y"], 0),
cmd,
zStart,
zFinal,
pitch,
)
else:
PathLog.error("No suitable Tool found for thread milling operation")
def opSetDefaultValues(self, obj, job):
PathLog.track()
obj.ThreadOrientation = self.RightHand
obj.ThreadType = self.ThreadTypeMetricInternal6H
obj.ThreadFit = 50
obj.Pitch = 1
obj.TPI = 0
obj.Passes = 1
obj.Direction = self.DirectionClimb
obj.LeadInOut = False
def isToolSupported(self, obj, tool):
"""Thread milling only supports thread milling cutters."""
support = hasattr(tool, "Diameter") and hasattr(tool, "Crest")
PathLog.track(tool.Label, support)
return support
def SetupProperties():
setup = []
setup.append("ThreadOrientation")
setup.append("ThreadType")
setup.append("ThreadName")
setup.append("ThreadFit")
setup.append("MajorDiameter")
setup.append("MinorDiameter")
setup.append("Pitch")
setup.append("TPI")
setup.append("Passes")
setup.append("Direction")
setup.append("LeadInOut")
return setup
def Create(name, obj=None, parentJob=None):
"""Create(name) ... Creates and returns a thread milling operation."""
if obj is None:
obj = FreeCAD.ActiveDocument.addObject("Path::FeaturePython", name)
obj.Proxy = ObjectThreadMilling(obj, name, parentJob)
if obj.Proxy:
obj.Proxy.findAllHoles(obj)
return obj