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<p>[QUOTE=&quot;green18, post: 1450757, member: 10103&quot;]This.....</p><p><br /></p><p><br /></p><p>In 2008 the Mint announced major advances for the development of the master design models that are used to produce the master hubs.&nbsp; According to the Mint, engravers at the Mint now have the option to continue to make physical models (galvanos) of the coin designs, or they can use sophisticated computer programs to make 3-D computer models of a coin’s design.&nbsp; If the engraver does choose to create the traditional physical models, the completed models can be scanned into the computer using special 3-D scanning equipment.&nbsp; Consequently, whether produced from scratch on the computer or created as a physical model, the coin design ultimately ends up as a 3-D computer image.</p><p><br /></p><p>Once the coin design is in the computer and deemed satisfactory, new CNC (computer numerical control) milling machines carve the design directly onto the face of a master hub.&nbsp; The Janvier Reduction Lathes in use at the Philadelphia Mint since 1907 are now a thing of the past.&nbsp; The new CNC milling machines can create a master hub in about half the time it took the Janvier Reduction Lathes to do the same job.</p><p><br /></p><p>Once the master hub is created, it is used to make some test dies that strike sample coins.&nbsp; If there are any problems, the design can be tweaked in the computer and a new master hub created.&nbsp; Once the Mint is satisfied that all is as it should be, the master hub is used to make the appropriate master dies.&nbsp; The remainder of the process remains the same with the master dies being used to create the working hubs, and the working hubs then being used to make the working dies that will be used to strike the coins.</p><p><br /></p><p><br /></p><p>citation:&nbsp; <a href="http://doubleddie.com/58201.html" target="_blank" class="externalLink ProxyLink" data-proxy-href="http://doubleddie.com/58201.html" rel="nofollow">http://doubleddie.com/58201.html</a>[/QUOTE]</p><p><br /></p>

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