FIAT shower drain cover

thingiverse

This is a replacement for a 20+ year-old plastic FIAT shower drain cover. It is nominally a 4.5" square cover, but the shape is between a square and a circle. I designed it to be fairly faithful to the original, but did beef up the underside supports. When I set out to design it I was concerned about how I would replicate the odd shape. But I was lucky that my first attempt at defining the shape (using my mathematics background) happened to be dead on. This replacement matches the shape of the original exactly and fits in the shower pan perfectly. Edit 1/22/2021. I added a second version with a more modern-looking drain design; something that couldn't be injection molded in 1 piece like the original. For those interested in the shape, here it is as a parametric curve in polar coordinates. D1 is the dimension of the square (116.5 mm), and D2 is the diagonal diameter (124.5 mm). (Note that the angle t is measured in radians not degrees.) (t, r(t)), r(t) = 0.5 * (D1 + (D2-D1) * sin(2*t)**2) I'm new to printing and designing, so comments are very welcome. I printed this in PETG, but I gather that ABS would be a better choice.