I can't really code so all credit goes to the original coder andreidescult. I just hacked the file to fix some issues and add some more features to make it more versatile.

It's a great pipe cup and being openscad means everybody can use it. The split part variety makes it unique and it really holds well.

check the console output when rendering to get the Minimum screw length, else most parameters are well explained in the file

I removed Cylindrical_Hex/Torx option which didn't work for me

fixed Top_Size to work with different sizes (original was working only with 2mm

added a ratio of nut part to screw part size to adjust Inner_Size_Factor. So now you can adjust which of the two parts will be longer

added a layer of one thickness to the nut (inner) part and to the screw (outer) part if Cylindrical or Hexagonal (if Sunken, only the inner part needs the extra layer) in order to be able to print without supports. This layer has to be removed with a drill bit afterwords, but it's quite easier than adding supports.