Bell trap drain covers.

thingiverse

I replaced a rubberized roof covering on my house, which features a bell trap drain recessed under it. To ensure water can flow freely underneath, I caulked the area around the drain. For added protection, I created a custom cover that wouldn't obstruct water drainage. The original design was loose-fitting, so I scaled it up to fit perfectly. I also experimented with adding a trim ring and incorporating it into the body of the cover, which would allow it to go through the roofing material. To bring my designs to life, I used 123D Design, Slic3r, and Matter Control version 1.7.5.