Vent or drain cap with integral screen

A parametized OpenSCAD model of a vent or drain cap with an included screen on the end. Parameters include:

+ Throat (non-screened end) depth, height and opening
+ Mouth (screened end) depth, height and opening
+ Screen size and opening

Note that it has only been run with the *mouth bigger than the throat.* If you need it the opposite way, you may need to tweak the model.

Note also that this thing takes *quite a long time* to render in OpenSCAD (about 30 minutes on an i5 under Win7)