I had a very limited space in which to install a grille on a ventilation outlet for a hood. I couldn't reduce the surface area of the pipe because it would create turbulence.

I designed this box, which has a larger emission surface area than the pipe and does not obstruct the air flow.

The Fusion project is parametric.

It is currently set up for a 120 mm pipe.

I also designed a sheet metal model, which I printed and transferred to an aluminium grating. It was easy to cut with wire cutters and bend with a vice.

I printed it in PETG and then painted it, but now that I have a closed printer, I would have done it in ASA.