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Initial version of the constraints docs
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‎doc/_static/door_assy.png

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‎doc/_static/door_assy_freecad.png

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‎doc/assy.rst

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.. _assy_tutorial:
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***********************
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Assembly Tutorial
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***********************
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Introduction
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============
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The purpose of this section is to demonstrate how to use the assembly and constraints
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functionality to build a realistic model. It will be a enclosure door assembly made out of 20x20 v-slot profiles.
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Defining parameters
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===================
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We want to start with defining the model parameters to allow for easy dimension changes later:
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.. code-block:: python
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:linenos:
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import cadquery as cq
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# Parameters
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H = 400
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W = 200
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D = 350
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PROFILE = cq.importers.importDXF("vslot-2020_1.dxf").wires()
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SLOT_D = 5
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PANEL_T = 3
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HANDLE_D = 20
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HANDLE_L = 50
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HANDLE_W = 4
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It is interesting to note that the v-slot profile is imported from a DXF file.
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This way it is very easy to change to other aluminum extrusion type, e.g. Item or Bosch.
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Vendors usually provide DXF files.
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Defining reusable components
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============================
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Next we want to define functions generating the assembly components based on the specified parameters.
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.. code-block:: python
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:linenos:
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def make_vslot(l):
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return PROFILE.toPending().extrude(l)
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def make_connector():
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rv = (
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cq.Workplane()
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.box(20, 20, 20)
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.faces("<X")
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.workplane()
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.cboreHole(6, 15, 18)
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.faces("<Z")
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.workplane()
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.cboreHole(6, 15, 18)
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)
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# tag mating faces
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rv.faces(">X").tag("X").end()
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rv.faces(">Z").tag("Z").end()
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return rv
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def make_panel(w, h, t):
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rv = (
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cq.Workplane("XZ")
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.rect(w, h)
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.extrude(t)
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.faces("<Y")
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.workplane()
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.pushPoints([(-w / 3, HANDLE_L / 2), (-w / 3, -HANDLE_L / 2)])
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.hole(3)
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)
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# tag mating edges
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rv.faces(">Y").edges("%CIRCLE").edges(">Z").tag("hole1")
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rv.faces(">Y").edges("%CIRCLE").edges("<Z").tag("hole2")
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return rv
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def make_handle(w, h, r):
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pts = ((0, 0), (w, 0), (w, h), (0, h))
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path = cq.Workplane().polyline(pts)
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rv = (
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cq.Workplane("YZ")
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.rect(r, r)
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.sweep(path, transition="round")
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.tag("solid")
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.faces("<X")
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.workplane()
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.faces("<X", tag="solid")
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.hole(r / 1.5)
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)
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# tag mating faces
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rv.faces("<X").faces(">Y").tag("mate1")
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rv.faces("<X").faces("<Y").tag("mate2")
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return rv
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Initial assembly
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================
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Next we want to instantiate all the components and add them to the assembly.
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.. code-block:: python
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:linenos:
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# define the elements
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door = (
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cq.Assembly()
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.add(make_vslot(H), name="left")
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.add(make_vslot(H), name="right")
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.add(make_vslot(W), name="top")
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.add(make_vslot(W), name="bottom")
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.add(make_connector(), name="con_tl", color=cq.Color("black"))
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.add(make_connector(), name="con_tr", color=cq.Color("black"))
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.add(make_connector(), name="con_bl", color=cq.Color("black"))
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.add(make_connector(), name="con_br", color=cq.Color("black"))
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.add(
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make_panel(W + SLOT_D, H + SLOT_D, PANEL_T),
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name="panel",
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color=cq.Color(0, 0, 1, 0.2),
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)
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.add(
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make_handle(HANDLE_D, HANDLE_L, HANDLE_W),
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name="handle",
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color=cq.Color("yellow"),
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)
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)
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Constraints definition
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======================
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Then we want to define all the constraints
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.. code-block:: python
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:linenos:
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# define the elements
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door = (
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cq.Assembly()
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.add(make_vslot(H), name="left")
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.add(make_vslot(H), name="right")
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.add(make_vslot(W), name="top")
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.add(make_vslot(W), name="bottom")
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.add(make_connector(), name="con_tl", color=cq.Color("black"))
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.add(make_connector(), name="con_tr", color=cq.Color("black"))
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.add(make_connector(), name="con_bl", color=cq.Color("black"))
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.add(make_connector(), name="con_br", color=cq.Color("black"))
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.add(
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make_panel(W + SLOT_D, H + SLOT_D, PANEL_T),
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name="panel",
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color=cq.Color(0, 0, 1, 0.2),
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)
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.add(
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make_handle(HANDLE_D, HANDLE_L, HANDLE_W),
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name="handle",
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color=cq.Color("yellow"),
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)
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)
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Final result
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============
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Below is the complete code including the final solve step.
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.. code-block:: python
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:linenos:
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import cadquery as cq
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# Parameters
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H = 400
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W = 200
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D = 350
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PROFILE = cq.importers.importDXF("vslot-2020_1.dxf").wires()
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SLOT_D = 5
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PANEL_T = 3
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HANDLE_D = 20
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HANDLE_L = 50
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HANDLE_W = 4
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def make_vslot(l):
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return PROFILE.toPending().extrude(l)
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def make_connector():
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rv = (
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cq.Workplane()
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.box(20, 20, 20)
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.faces("<X")
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.workplane()
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.cboreHole(6, 15, 18)
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.faces("<Z")
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.workplane()
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.cboreHole(6, 15, 18)
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)
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# tag mating faces
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rv.faces(">X").tag("X").end()
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rv.faces(">Z").tag("Z").end()
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return rv
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def make_panel(w, h, t):
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rv = (
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cq.Workplane("XZ")
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.rect(w, h)
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.extrude(t)
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.faces("<Y")
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.workplane()
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.pushPoints([(-w / 3, HANDLE_L / 2), (-w / 3, -HANDLE_L / 2)])
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.hole(3)
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)
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# tag mating edges
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rv.faces(">Y").edges("%CIRCLE").edges(">Z").tag("hole1")
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rv.faces(">Y").edges("%CIRCLE").edges("<Z").tag("hole2")
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return rv
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def make_handle(w, h, r):
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pts = ((0, 0), (w, 0), (w, h), (0, h))
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path = cq.Workplane().polyline(pts)
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rv = (
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cq.Workplane("YZ")
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.rect(r, r)
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.sweep(path, transition="round")
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.tag("solid")
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.faces("<X")
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.workplane()
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.faces("<X", tag="solid")
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.hole(r / 1.5)
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)
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# tag mating faces
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rv.faces("<X").faces(">Y").tag("mate1")
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rv.faces("<X").faces("<Y").tag("mate2")
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return rv
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# define the elements
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door = (
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cq.Assembly()
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.add(make_vslot(H), name="left")
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.add(make_vslot(H), name="right")
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.add(make_vslot(W), name="top")
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.add(make_vslot(W), name="bottom")
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.add(make_connector(), name="con_tl", color=cq.Color("black"))
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.add(make_connector(), name="con_tr", color=cq.Color("black"))
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.add(make_connector(), name="con_bl", color=cq.Color("black"))
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.add(make_connector(), name="con_br", color=cq.Color("black"))
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.add(
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make_panel(W + SLOT_D, H + SLOT_D, PANEL_T),
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name="panel",
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color=cq.Color(0, 0, 1, 0.2),
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)
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.add(
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make_handle(HANDLE_D, HANDLE_L, HANDLE_W),
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name="handle",
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color=cq.Color("yellow"),
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)
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)
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# define the constraints
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(
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door
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# left profile
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.constrain("left@faces@<Z", "con_bl?Z", "Plane")
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.constrain("left@faces@<X", "con_bl?X", "Axis")
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.constrain("left@faces@>Z", "con_tl?Z", "Plane")
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.constrain("left@faces@<X", "con_tl?X", "Axis")
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# top
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.constrain("top@faces@<Z", "con_tl?X", "Plane")
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.constrain("top@faces@<Y", "con_tl@faces@>Y", "Axis")
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# bottom
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.constrain("bottom@faces@<Y", "con_bl@faces@>Y", "Axis")
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.constrain("bottom@faces@>Z", "con_bl?X", "Plane")
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# right connectors
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.constrain("top@faces@>Z", "con_tr@faces@>X", "Plane")
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.constrain("bottom@faces@<Z", "con_br@faces@>X", "Plane")
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.constrain("left@faces@>Z", "con_tr?Z", "Axis")
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.constrain("left@faces@<Z", "con_br?Z", "Axis")
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# right profile
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.constrain("right@faces@>Z", "con_tr@faces@>Z", "Plane")
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.constrain("right@faces@<X", "left@faces@<X", "Axis")
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# panel
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.constrain("left@faces@>X[-4]", "panel@faces@<X", "Plane")
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.constrain("left@faces@>Z", "panel@faces@>Z", "Axis")
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# handle
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.constrain("panel?hole1", "handle?mate1", "Plane")
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.constrain("panel?hole2", "handle?mate2", "Point")
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)
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# solve
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door.solve()
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show_object(door,name='door')
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This code generates the following assembly.
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.. image:: _static/door_assy.png
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Data export
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===========
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The resulting assembly can be exported as a STEP file or in a internal OCCT XML format.
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STEP can be loaded in all CAD tool, e.g. in FreeCAD and the XML be used in other applications using OCCT.
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.. code-block:: python
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:linenos:
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door.save('door.step')
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door.save('door.xml')
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In the case of STEP colors are preserved but not transparency.
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.. image:: _static/door_assy_freecad.png

‎doc/index.rst

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quickstart.rst
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designprinciples.rst
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primer.rst
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assy.rst
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fileformat.rst
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examples.rst
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apireference.rst

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