how to measure a ring for cnc.

hi, i've just joined this site, have been having a browse and was wondering- how do you go about scanning an item so that it can be replicated/cnc machined? i've read about 3d scanning, is this the only way to accurately copy an item and present it ready for cnc programming? i have a ring that i bought in peru about 15 years ago, its silver and am wanting to copy it to steel or aluminium. its very intricate with 'platform' design and as such, cannot be put onto paper since there is no way i can measure all the dimensions accurately. are there any companies in the uk that you would recconmend for this type of work?also, what sort of pricerange would a service like this cost? thanks in advance, will.:question:

There's a reason that intricate rings are usually in silver or gold, it's dead easy to replicate them by lost wax casting and then stretch them to size :naughty:

i've already had it replicated in silver, using the lost wax method, that was about 1999. cost me £55 which was when silver was a lot cheaper than now. i lost that copy when i was playing cricket.within a year.i was under the impression that this method can't be used with alu or stainless steel due to the higher melting points.

Using the lost wax process what you cast is not limited to the melting point of the metal or alloy but to the material around the wax.
Aluminium could be the most difficult as its not that heavy and most lost wax processes for rings and dentistry use a melt and centrifuge process to actually cast the metal.
Stainless can be used as it is used in dentistry and that melts at about 1363C
The most time consuming would be cnc unless you are going to make lots of them just producing the code would be quite onerous.

Peter

ok, so i see lost wax is the way forward for this. if i was to use cnc, how would i scan the ring to be able to add to a cnc program, are there any people who will scan for a reasonable price:question: