Interlocking cubes
thingiverse
I had another go at finding that original photo, and I think it was the one with Richard Gain's ducted fan for Mendel90 on pinshape.com/items/4488-3d-printed-low-profile-ducted-fan-for-mendel90-with-e3dv4-hot-end. I saw this design in a random photo, but couldn't find an STL for it. It looked like an interesting thing to print so I created a model in OnShape: cad.onshape.com/documents/62fc907018bdbbbd171f23c2/w/481169a229d6a1f2a706b3fd/e/0e2eea80694bd9a8650d3542. I found it quite difficult to print because the overhangs are about 35 degrees and they have a tendency to curl, and the bed contact area isn't very big. But it did eventually work without supports, although it's not the cleanest print I've made.
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