diamond gold ring printable jewel engagement ring 3D print model

I am a designer also a modeler, i have been engaged on Jewelry 3d printing years, I would like to share how to use the 3d Printer to print the design and which way to casting it well. Ring Size: 22 mm(adjustable). Gold 18 ct : 5.5 g Diamond : 0.81 ct / 6.0 mm Available formats upon request: .c4d, .obj, .fbx, .ma/.mb, .lwo/.lws, .3ds, .3dm, .dxf/.dwg, .stl.