Reworked the core examples to exclude contributed examples.

examples/Ex005_Extruded_Lines_and_Arcs.py

@@ -0,0 +1,45 @@
+import cadquery as cq
+
+# These can be modified rather than hardcoding values for each dimension.
+width = 2.0         # Overall width of the plate
+thickness = 0.25    # Thickness of the plate
+
+# Extrude a plate outline made of lines and an arc
+# 1.  Establishes a workplane that an object can be built on.
+# 1a. Uses the named plane orientation "front" to define the workplane, meaning
+#     that the positive Z direction is "up", and the negative Z direction
+#     is "down".
+# 2.  Draws a line from the origin to an X position of the plate's width.
+# 2a. The starting point of a 2D drawing like this will be at the center of the
+#     workplane (0, 0) unless the moveTo() function moves the starting point.
+# 3.  A line is drawn from the last position straight up in the Y direction
+#     1.0 millimeters.
+# 4.  An arc is drawn from the last point, through point (1.0, 1.5) which is
+#     half-way back to the origin in the X direction and 0.5 mm above where
+#     the last line ended at. The arc then ends at (0.0, 1.0), which is 1.0 mm
+#     above (in the Y direction) where our first line started from.
+# 5.  An arc is drawn from the last point that ends on (-0.5, 1.0), the sag of
+#     the curve 0.2 determines that the curve is concave with the midpoint 0.1 mm
+#     from the arc baseline. If the sag was -0.2 the arc would be convex.
+#     This convention is valid when the profile is drawn counterclockwise.
+#     The reverse is true if the profile is drawn clockwise.
+#     Clockwise:        +sag => convex,  -sag => concave
+#     Counterclockwise: +sag => concave, -sag => convex
+# 6.  An arc is drawn from the last point that ends on (-0.7, -0.2), the arc is
+#     determined by the radius of -1.5 mm.
+#     Clockwise:        +radius => convex,  -radius => concave
+#     Counterclockwise: +radius => concave, -radius => convex
+# 7.  close() is called to automatically draw the last line for us and close
+#     the sketch so that it can be extruded.
+# 7a. Without the close(), the 2D sketch will be left open and the extrude
+#     operation will provide unpredictable results.
+# 8.  The 2D sketch is extruded into a solid object of the specified thickness.
+result = cq.Workplane("front").lineTo(width, 0) \
+                              .lineTo(width, 1.0) \
+                              .threePointArc((1.0, 1.5), (0.0, 1.0)) \
+                              .sagittaArc((-0.5, 1.0), 0.2) \
+                              .radiusArc((-0.7, -0.2), -1.5) \
+                              .close().extrude(thickness)
+
+# Displays the result of this script
+show_object(result)