freecad-cam/Mod/CAM/Path/Base/Generator/helix.py
2026-02-01 01:59:24 +01:00

239 lines
8.6 KiB
Python

# -*- coding: utf-8 -*-
# ***************************************************************************
# * Copyright (c) 2021 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 numpy import ceil, linspace, isclose
import Path
__title__ = "Helix toolpath Generator"
__author__ = "sliptonic (Brad Collette)"
__url__ = "https://www.freecad.org"
__doc__ = "Generates the helical toolpath for a single spot targetshape"
__contributors__ = "russ4262 (Russell Johnson), Lorenz Hüdepohl"
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())
def generate(
edge,
hole_radius,
step_down,
step_over,
tool_diameter,
inner_radius=0.0,
direction="CW",
startAt="Outside",
):
"""generate(edge, hole_radius, inner_radius, step_over) ... generate helix commands.
hole_radius, inner_radius: outer and inner radius of the hole
step_over: step over % of tool diameter"""
startPoint = edge.Vertexes[0].Point
endPoint = edge.Vertexes[1].Point
Path.Log.track(
"(helix: <{}, {}>\n hole radius {}\n inner radius {}\n step over {}\n start point {}\n end point {}\n step_down {}\n tool diameter {}\n direction {}\n startAt {})".format(
startPoint.x,
startPoint.y,
hole_radius,
inner_radius,
step_over,
startPoint.z,
endPoint.z,
step_down,
tool_diameter,
direction,
startAt,
)
)
# inner_radius contains not a radius but the value from Extra Offset, which is the distance between the hole radius as designed and the hole radius to be cut.
# hole_radius contains the designed hole radius - inner_radius.
if type(hole_radius) not in [float, int]:
raise TypeError("Invalid type for hole radius")
if hole_radius < 0.0:
raise ValueError("hole_radius < 0")
if type(inner_radius) not in [float, int]:
raise TypeError("inner_radius must be a float")
if type(tool_diameter) not in [float, int]:
raise TypeError("tool_diameter must be a float")
if not hole_radius * 2 > tool_diameter:
raise ValueError(
"Cannot helix a hole of diameter {0} with a tool of diameter {1}".format(
2 * hole_radius, tool_diameter
)
)
elif startAt not in ["Inside", "Outside"]:
raise ValueError("Invalid value for parameter 'startAt'")
elif direction not in ["CW", "CCW"]:
raise ValueError("Invalid value for parameter 'direction'")
if type(step_over) not in [float, int]:
raise TypeError("Invalid value for parameter 'step_over'")
if step_over <= 0 or step_over > 1:
raise ValueError("Invalid value for parameter 'step_over'")
step_over_distance = step_over * tool_diameter
if not (
isclose(startPoint.sub(endPoint).x, 0, rtol=1e-05, atol=1e-06)
and (isclose(startPoint.sub(endPoint).y, 0, rtol=1e-05, atol=1e-06))
):
raise ValueError("edge is not aligned with Z axis")
if startPoint.z < endPoint.z:
raise ValueError("start point is below end point")
if hole_radius <= tool_diameter:
Path.Log.debug("(single helix mode)\n")
radii = [hole_radius - tool_diameter / 2]
if radii[0] <= 0:
raise ValueError(
"Cannot helix a hole of diameter {0} with a tool of diameter {1}".format(
2 * hole_radius, tool_diameter
)
)
outer_radius = hole_radius
else: # inner_radius > 0:
Path.Log.debug("(annulus mode / full hole)\n")
outer_radius = hole_radius - tool_diameter / 2
step_radius = inner_radius + tool_diameter / 2
if abs((outer_radius - step_radius) / step_over_distance) < 1e-5:
radii = [(outer_radius + inner_radius) / 2]
else:
nr = max(int(ceil((outer_radius - inner_radius) / step_over_distance)), 2)
radii = linspace(outer_radius, step_radius, nr)
Path.Log.debug("Radii: {}".format(radii))
# calculate the number of full and partial turns required
# Each full turn is two 180 degree arcs. Zsteps is equally spaced step
# down values
turncount = max(int(ceil((startPoint.z - endPoint.z) / step_down)), 2)
zsteps = linspace(startPoint.z, endPoint.z, 2 * turncount + 1)
def helix_cut_r(r):
commandlist = []
arc_cmd = "G2" if direction == "CW" else "G3"
commandlist.append(Path.Command("G0", {"X": startPoint.x + r, "Y": startPoint.y}))
commandlist.append(Path.Command("G1", {"Z": startPoint.z}))
for i in range(1, turncount + 1):
commandlist.append(
Path.Command(
arc_cmd,
{
"X": startPoint.x - r,
"Y": startPoint.y,
"Z": zsteps[2 * i - 1],
"I": -r,
"J": 0.0,
},
)
)
commandlist.append(
Path.Command(
arc_cmd,
{
"X": startPoint.x + r,
"Y": startPoint.y,
"Z": zsteps[2 * i],
"I": r,
"J": 0.0,
},
)
)
commandlist.append(
Path.Command(
arc_cmd,
{
"X": startPoint.x - r,
"Y": startPoint.y,
"Z": endPoint.z,
"I": -r,
"J": 0.0,
},
)
)
commandlist.append(
Path.Command(
arc_cmd,
{
"X": startPoint.x + r,
"Y": startPoint.y,
"Z": endPoint.z,
"I": r,
"J": 0.0,
},
)
)
return commandlist
def retract():
# try to move to a safe place to retract without leaving a dwell
# mark
retractcommands = []
# Calculate retraction
if hole_radius <= tool_diameter: # simple case where center is clear
center_clear = True
elif startAt == "Inside" and inner_radius == 0.0: # middle is clear
center_clear = True
else:
center_clear = False
if center_clear:
retractcommands.append(
Path.Command("G0", {"X": endPoint.x, "Y": endPoint.y, "Z": endPoint.z})
)
# Technical Debt.
# If the operation is clearing multiple passes in annulus mode (inner
# radius > 0.0 and len(radii) > 1) then there is a derivable
# safe place which does not touch the inner or outer wall on all radii except
# the first. This is left as a future improvement.
retractcommands.append(Path.Command("G0", {"Z": startPoint.z}))
return retractcommands
if startAt == "Inside":
radii = radii[::-1]
commands = []
for r in radii:
commands.extend(helix_cut_r(r))
commands.extend(retract())
return commands