Customizable Curtain Rod Holder

I told my wife that I was going to print curtain rod holders, and she was correctly worried that the weight of the rod would shear the layers. So I designed these so that the curtain rod would rest on a metal screw which would keep the layers together. This is a customizable curtain rod holder, the parameters include: rod diameter, inner diameter of the screw you're going to use (from which pre-drilled and sunk holes are calculated), the type of screw your going to use (pan head, flat head, or socket), the thickness, and resolution, along with some others. The countersink parameters, and final diameter are shown in preview mode, and will not be exported to STL (using the $preview parameter in OpenSCAD). The included STL is designed for US#8 pan head screws, and at 23mm, can fit either a US 3/4" electrical conduit, or US 3/4" copper water pipe. The pictured print was printed in PLA, at 0.2mm layer height, 20% rectilinear infill, and actually features screws from 4 different sets, all #8 pan-head.