The Chimney Swallows block from page 128 of Beyer’s book:
The tool (blue & orange) and top cut (red) layers:
The long radial blue tool lines simplified selecting them when mirroring / duplicating the cut polygons around their symmetries. The orange tool circles aligned various midpoints / vertices / features during construction.
The inward curve along the outer edge started as a triangle with a node at about the middle of the curve. Deleting that node left the remaining two sides overlapped, but dragging one of them to match the curve worked OK. There’s probably a better way.
That curve defines the outer edges of the shapes along it, so I drew polygons from the corner intersections and dragged the outer edge to match the curve at high zoom.
The shape remains selected after dragging the side, which meant I could immediately apply a 1 mm inset to create the cut lines.
To my surprise, the swallow bodies are straight-sided polygons!
After taking advantage of all the symmetries, knock out the shapes defining each layer:
The swallows look like F-117 Nighthawks to me:
Maybe I have the colors wrong:
Fly away!
The Smell of Molten Projects in the Morning 