Parametric Axial Cooling Fan Shroud

I spent days looking for a fan shroud that would not blow on my hotend but which would provide a cooling air flow. There were lots of fan mounts, but they were all designed to fit some extruder or other. I had a uniquie situation, and I just could not find a fan mount to fit. I grabbed a couple, made clips and they didn't work for one reason or another.

One of them was a parametric openSCAD ring funnel that was not parametric enough. I fixed a couple bugs in that code, learned a little ope