Hey there, I have very limited experience in 3d design, but thought this may be an easy project to start. I had my fiancé's engagement ring 3d designed and printed and I want to do the wedding ring myself. All I need to do is make a 3d model for shapeways that has rounded edges and nests against the other ring, and I have the stl file of it. Basically, I just need to outline one side of that. Could someone guide me on this? I can use any free software for it. I attached the STL file as a guide, and the image is the idea that I'm looking for. I'm not doing anything as complicated as that, but you can see how they wrap around each other. Thanks!
I would suggest using DesignSpark Mechanical, it's free. https://www.rs-online.com/designspark/mechanical-software It can convert your STL file into a solid, from there you can draw a cylinder and use the 'Boolean Subtract' command to 'cut' your original ring from the new solid.