jmwright/cadquery_tips_and_tricks.md

## cadquery_tips_and_tricks.md

      
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              cadquery_tips_and_tricks.md
            
          
    1. Conda Installation

If you use conda you might try creating a new environment and install using conda directly:
  conda create -n cadquery-master
  conda install -c cadquery -c conda-forge cadquery=master

Or if you want both cq-editor and cadquery:
  conda create -n cqgui-master
  conda install -c cadquery -c conda-forge cq-editor=master

2. Conda Update

This will allow you to update a Conda environment.
conda remove cq-editor
conda clean --all --force-pkgs-dirs
conda install --force-reinstall -c conda-forge -c cadquery cq-editor=master

3. Reusing wires from a face.

result = ( cq.Workplane("XY") .box(2.0, 2.0, 0.5) .faces(">Y").wires().toPending().offset2D(-.1) .transformed(rotate=(-90,0,0)).extrude(.5) )

4. Standalone 3D viewer

import sys
from OCP.BRepPrimAPI import BRepPrimAPI_MakeBox
from cq_editor.widgets import viewer as cqv
import cadquery as cq


app = cqv.QApplication(sys.argv)
viewer = cqv.OCCViewer()

dlg = cqv.QDialog()
dlg.setFixedHeight(400)
dlg.setFixedWidth(600)

cqv.layout(dlg,(viewer,),dlg)
dlg.show()

#box = BRepPrimAPI_MakeBox(20,20,30)
box = cq.Workplane("XY").box(20,20,30).val().wrapped
box_ais = cqv.AIS_ColoredShape(box)

viewer.display(box_ais)
sys.exit(app.exec_())

This helper can also be used in conjunction with this.
5. Use of lambdas

.each(lambda p: p.scale(25.4))

6. Show all wires in CQ-editor

res = cq.Workplane().rect(1,1).rect(3,3).consolidateWires()

7. Monkey-patch show_object into code

Put this at the top of your script and show_object() will have no effect when running outside of CQ-editor:

if 'show_object' not in globals():
    def show_object(*args, **kwargs):
        pass

If you want to use show_object inside non-main modules you can do this (it's a bit of a hack though)
# (main module)
import my_other_module

my_other_module.show_object = show_object

8. Set Alpha and Highlight Face in Color in CQ-editor

res = (
       cq.Workplane()
       .ellipse(10,5)
       .workplane(10)
       .ellipse(8,10)
       .loft()
)

res2 = res.faces('>Z')

show_object(res,'res',options=dict(alpha=0.9))
show_object(res2,'res2',options=dict(alpha=0.1,color=(1.,0,0)))

Link
9. Select Arbitrary Axes

stand.faces('>Z').edges('|(1,1,0) or |(1,-1,0)')

Link
10. Finding Everything That Is Installed By Anaconda

conda create --dry-run --json -n dummy <package>

Link
11. Using Multiplication for Locations

L =  Ltrans*Lrot1 * Lrto2

Link
12. Torus Generation

import cadquery as cq

path = cq.Workplane().slot2D(20,5)
sweep = cq.Workplane("YZ", origin = (0,2.5)).slot2D(3,2,90).sweep(path)
revolve = cq.Workplane("XZ").move(10,-10).slot2D(2.5,2).wire().revolve(360,(0,0),(0,1))

Source: Discord
13. Fix CQ-editor On Manjaro

sudo mcopy /lib/libstdc++.so.6 ~/.conda/envs/cqgui/lib

Source: Google Groups
14. Adding an Offset Between Two Parts in an Assembly with a Dummy Vertex

a = cq.Workplane("XY").rect(xLen=1, yLen=2).extrude(5)
b = cq.Workplane("XY").rect(xLen=2, yLen=1).extrude(10)

assembly = (
    cq.Assembly(a, name="a", color=cq.Color("red"))
    .add(b, name="b", color=cq.Color("green"))
)
assembly.constrain(
    "a",
    cq.Vertex.makeVertex(3, 0, 0),
    "b",
    b.vertices("<X and <Y and <Z").val(),
    "Point",
)
assembly.constrain("a@faces@>X", "b@faces@<X", "Axis")
assembly.solve()

show_object(assembly)
15. Using describe_parameter()

height = 60.0
describe_parameter(height, '30.0 140.0')

width = 80.0
describe_parameter(width, '20.0 100.0')

Source: GitHub
16. Importing an STL With the cqMore Extension

Sample code is here
Source: Google Groups
17. Use the Sketch feature to create a cut with filleted edges inside a box.

import cadquery as cq

s1 = (
    cq.Sketch()
    .rect(30, 40)
    .rect(10, 10, mode="s", tag="rectcut")
    .vertices(">X", tag="rectcut")
    .fillet(1)
    .vertices("<X", tag="rectcut")
    .fillet(2)
)

r = cq.Workplane().placeSketch(s1).extrude(10)
Source: Discord
17. How to Fix "Developer Cannot Be Verified" on MacOS

If there is an error similar to this:
Error loading Python lib '/Users/me/Downloads/CQ-editor-MacOS/CQ-editor/libpython3.8.dylib': dlopen: dlopen(/Users/me/Downloads/CQ-editor-MacOS/CQ-editor/libpython3.8.dylib, 10): no suitable image found. Did find:
/Users/me/Downloads/CQ-editor-MacOS/CQ-editor/libpython3.8.dylib: code signature in (/Users/me/Downloads/CQ-editor-MacOS/CQ-editor/libpython3.8.dylib) not valid for use in process using Library Validation: library load disallowed by system policy

Try this form:
xattr -r -d com.apple.quarantine path/to/CQ-editor-MacOS

Source GitHub
18. Get the Global Rather than Local Coordinates (xmin, ymax, etc) of a BoundingBox

# Font that is offset and not symmetrical in all axes
text = cq.Workplane().text("X", 12, 1, False, True)

# Get the bounding box, which will have xmin, ymin, etc in local coordinates
bbox = text.val().BoundingBox()

# Alernative way to get the center that is not needed
# cen = text.val().CenterOfBoundBox()

# Move the bounding box and draw a rect to represent it (this was displayed in CQ-editor)
bb = cq.Workplane().moveTo(bbox.center.x, bbox.center.y).rect(bbox.xmax-bbox.xmin, bbox.ymax-bbox.ymin).extrude(1)
Source Google Groups
19. Sweep a Circle in the Normal Direction

pts = [
    (1, 1, 1),
    (1, 2, 2),
    (1, 3, 3),
]
p = cq.Workplane("XY").spline(pts, includeCurrent=True)
dire = p.val().tangentAt(0)
plane = cq.Plane((0,0,0), normal=dire)
s = cq.Workplane(plane).circle(1).sweep(p)
Source GitHub
20. Serialization to Enable Multiprocessing of Multiple Parts at Once

Paired with the helper shown here.
from multiprocessing import Pool
import cadquery as cq
from cq_serialize import register as register_cq_helper

register_cq_helper()

def make_box(size: float):
    return cq.Workplane("XY").box(size, size, size).findSolid()

with Pool() as p:
    boxes = p.map(make_box, range(1, 10))
Source GitHub
21. Getting pip Install Line to Work in zsh

You have to add single quotes around the package because of the way zsh interprets [ and ].
pip install 'cadquery[ipython]==2.2.0b0'

Source GitHub
22. How to Tell When clean=true Is Causing Problems

If you see ShapeUpgrade_UnifySameDomain in a CadQuery script's trace, then the issue is likely related to clean=True. Try clean=False instead.
Source Google Groups
23. Chamfer Curved (Non-Planar) Edges

head = (
    cq.Workplane("XZ")
    .lineTo(head_width2, 0)
    .ellipseArc(head_width2, head_height, angle1=0, angle2=90)
    .close()
    .revolve(360, axisStart=(0, 0, 0), axisEnd=(0, 1, 0))
    .cut(sock)
    .cut(sock.translate((1.5 * eye_offset, 0, 0)))
    .faces("not %Plane")
    .edges("not <Z")
    .edges("not <Y")
    .chamfer(1)
)

Source Google Groups
24. Export an SVG on a Workplane with Sketch

s = cq.Sketch().circle(1)
cq.exporters.export(s.faces().val(), "out.svg", opt={"projectionDir": (0, 0, 1)})

Source GitHub
25. Have a model execute in CQ-editor and as part of another Python script seamlessly

# Create the plate and show it in CQ-editor (if we are executing it that way)
if 'show_object' in globals():
    plate = generate()
    show_object(plate)

Source GitHub
25. Install CadQuery on Apple Silicon

$ arch -x86_64 brew install miniconda
$ arch -x86_64 conda install -c cadquery -c conda-forge cadquery=master
$ arch -x86_64 conda install -c cadquery -c conda-forge cq-editor=master
$ arch -x86_64 /opt/homebrew/Caskroom/miniconda/base/bin/python

Source GitHub
26. The Difference Between Fixed and FixedPoint Assembly Constraints


Fixed fixes all 6 degrees of freedom and FixedPoint fixes only 3 translational degrees of freedom.
Source GitHub

27. Find the Intersection of a Cylinder and a Line

from cadquery import *

c = Workplane().cylinder(5,1)
l = Workplane().moveTo(5,0).lineTo(-5,0)
res =  c.intersect(l).edges().val()

start = res.startPoint()
stop = res.endPoint()
lengt = res.Length()

Source GitHub
28. Install CQ-editor via pip

# Install cadquery and any other packages you are developing with `pip install -e .` while in those repo directories
# Install cadquery deps manually.
# cd into local copy of CQ-editor repo
pip install -e .

Source (kind of) GitHub
29. Tips for Decreasing Model Creation Time


Work in 2D as long as possible
Avoid boolean ops
If you must use boolean ops, do not use them in loops
If possible, use bool ops with glue=True
Turn off clean (set clean=False)

Source Google Groups
30. Setting Units Globally for STEP Export

import OCP

w = OCP.STEPControl.STEPControl_Writer()
OCP.Interface.Interface_Static.SetCVal_s("write.step.unit","UM")
Source Google Groups