Simple, customizable pipe flange design. The design is very flexible with many parameters to change.
I intentionally left out logic to prevent values that don't make sense. For example, you can set hole amount to 1000 and the center will be disconnected from the edges. There are cases when you want to use somewhat insane values and sometimes it would be useful to have limits but for not it's up to the user.
If you have any suggestions for improvement or just want to give feedback, feel free to leave a comment.
Edit 2018-03-05: Added 2 example images and related model. Switched to using diameters as that is what you get when you measure pipes.
Edit 2018-03-06 Added offset to adjust the screw position relative to middle position and added option for counter sunk screw holes.