Dear All,

I have been struggling to find an accurate formula for creating a template for a hollow form, signet style ring with an oval cabochon setting. There is one tutorial on ganoksin (project hollow ring I can't post the URL here as this is must first forum post) but there is no formula given for drawing out the template accurately
Can anyone point me in the right direction of a formula or directions for drawing up the template or do I need to keep on with my current trial and error method which is not yielding much in the way of results. The opening for the cabochon always seems to be too big or too small …. maths is not my strong point but I can't figure out exactly where I'm going wrong.
Also I live in a remote spot where getting my hands on materials is not easy and I need to conserve my resources so I don't want to keep making mistakes!

Thanks in advance for your assistance

Lucy