i needed a drain for my bathroom, seemed like less work to build one than go to the store at an odd hour in the morning. printed it up, and it works. took some time to make sure it was parametric before publishing. it uses inches, but you can remove the inch variable from lines and then use metric. for example default is 1.4inch, just remove inch. don't change inch variable scale because wall thickness of drain walls use it for calculations.
i have tested the design from 0.5inch to 15 inches diameter (i could spend time for the math to make it scale up past 15inches, or 380mm, but it doesn't seem needed. i printed out one about 1.4 inches. with default of 0.4inch height, or ~10mm height.
you can change the diameter, the lip size, and the quantity and thickness of grids for filter.
be sure to preview it first and make sure lip size is adjusted correctly as well. if you dont want lip, just set size to the same as top diameter
if all you want to do is scale it in slicer software such as cura, i have a 20mm drain size and a 1 inch drain size stl file for easy scale conversions without parametric openscad use
if scaling depth is 10mm, or about 0.4inches for reference.