Minimalist Silver Ring CAD Designs

I need three distinct ring models drawn up in CAD and supplied in a file format that can go straight to a casting house. All three pieces are for everyday wear, so the forms must feel light, clean-lined, and comfortable on the hand while still reading clearly in polished silver... (Budget: £5 - £10 GBP, Jobs: 3D CAD, 3D Design, 3D File Scaling, Slicing & Print Preparation, 3D Modelling, 3D Printing, 3D Rendering, AutoCAD, CAD/CAM)