Hi Jon. I tried email you but obviously have the wrong email address. I have been training in CAD for Jewelry design for over 9-years. Used many 3D printers in that time from $65k+ down to $5k. I would be interested in you trying some sample ring designs. They are my own which I use for training purposes, so you are free to test print, photograph and use them how you see fit. If you can advise an email address I will email you a zip file containing 3 x STL's to test print.
Regards, Rikj