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<p>[QUOTE=&quot;Ed Snible, post: 4839662, member: 82322&quot;]My local coin club recently had a custom medal struck by <a href="https://www.medalcraft.com/" target="_blank" class="externalLink ProxyLink" data-proxy-href="https://www.medalcraft.com/" rel="nofollow">https://www.medalcraft.com/</a> .&nbsp; We had an artist create plaster models, 12” in diameter, which were laser scanned to produce a digital model that drove a CNC *milling* machine to produce 2.5” dies.&nbsp; The resulting dies, although they were of sublime beauty, were not perfect fidelity copies of the plasters.</p><p><br /></p><p>I have heard that electrical discharge machining (spark eroding) can do a very deceptive job.&nbsp; I have been unable to locate photographs of coins or medals produced with CNC EDM machines as part of the process.&nbsp; I would love to see examples, if such work has ever been attempted, either by artists or forgers.</p><p><br /></p><p>If you have ever seen electrotype copies of Greek coins they are sublime and the quality is excellent.&nbsp; I would be especially curious to see a comparison of electrotype copies and copies with EDM as part of the process.</p><p><br /></p><p>Dies made from genuine coins are called “transfer dies”.</p><p><br /></p><p>Dies can be cast from genuine coins.&nbsp; The resulting dies produce coins about 1-2% smaller.&nbsp; The quality is higher than CNC milling.</p><p><br /></p><p>Here is an extreme enlargement of one of the side figures on the reverse of my club to show the difference.&nbsp; In hand, the medal looks great, but careful side-by-side inspection, especially with magnification, shows differences.</p><p>[ATTACH=full]1169308[/ATTACH][/QUOTE]</p><p><br /></p>

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