Using Openscad http://diy3dprinting.blogspot.ca/2015/10/how-to-design-chainring-using-open.html

To read : https://pignonfixe.com/topic/252/le-poseur-du-lac-deadishype-bertin/250

What is BCD https://www.wolftoothcomponents.com/pages/how-to-measure-bolt-circle-diameter-bcd

Custom solidworks file https://groups.google.com/forum/#!topic/framebuilders/1jwPghezrYY https://grabcad.com/library/tag/chainring?page=1&time=all_time&sort=recent

Voir onshape aussi