Log in or Sign up
Coin Talk
Home
Forums
>
Coin Forums
>
Error Coins
>
Single squeeze hubbing
>
Reply to Thread
Message:
<p>[QUOTE="Pickin and Grinin, post: 2634255, member: 73995"]I was looking for some good reads this morning and clicked on the site that got me started in coin collecting. <a href="http://www.conecaonline.org" target="_blank" class="externalLink ProxyLink" data-proxy-href="http://www.conecaonline.org" rel="nofollow">www.conecaonline.org</a> Until this morning I hadn't completely wrapped my head around the Single squeeze hubbing process. I knew that In the olden days they used a reduction lathe. which is why we have the major DDO's 55' 69'S, 70'S 72.</p><p>The below insert is from Wexlers web site.</p><p><br /></p><p>"The Mint started using reduction lathes in 1836 to transfer designs from a master model (galvano) to the face of a master hub. These reduction lathes were pantographs with two arms. One arm traced out the design on the galvano while the other reduced it proportionately and cut it into the face of the master hub. It was a very slow and tedious process and took anywhere from a day and a half to two days to complete a master hub.</p><p><br /></p><p style="text-align: left"><img src="http://www.doubleddie.com/mediac/450_0/media/Janvier$20Reduction$20Lathe.jpg" class="bbCodeImage wysiwygImage" alt="" unselectable="on" /></p><p><br /></p><p><br /></p><p>In 1996 the Denver Mint opened its own Die making shop. Introducing the single squeeze press to make master dies.[ATTACH=full]580141[/ATTACH] This was the end of the major DDO or so we thought.</p><p><br /></p><p>You can read the full article written by Ken Potter for Numismatic news on Coneca, below is what he wrote about the single Squeeze process, minus the cool pics.</p><p><br /></p><p>The United States Mint largely replaced the multiple hubbing process in recent years by the “single squeeze” restrained hubbing process. The “single squeeze” process produces doubled dies that are more often than not, restricted to the central areas of the design. The face of a die blank (referred to as a “die block” in Mint jargon) is machined with a slightly conical configuration to aid in the flow of metal during hubbing. This would indicate that the initial kiss of a hub into a die blank would be restricted to this centralized area before continuing on to fill out the rest of the design. During this process the tip of a tilted die blank would be positioned slightly off location away from the center of the hub into a different area of design than intended. After the initial contact, the pressure of the hub would eventually seat the die blank in proper position, and in turn cause doubling on the affected die.</p><p><br /></p><p>(Below referring to 2006, 2014 and 2015 DDO's)</p><p><br /></p><p>These recent-date Lincoln cent doubled dies have been breaking the rule of centralized doubling for reasons unknown. There could be any number of reasons for this but if I had to guess based on seeing more and more of these more “classic looking” obverse doubled dies since about 2010, I’d say that some part of the tooling in the hubbing process for cents has seen some wear resulting in a sloppy fit. This could allow for a shift to occur further along into the process of hubbing a die with the shift occurring at near the finishing point of the dies’ production.</p><p><br /></p><p>No matter the cause, with the Lincoln cent doubled dies increasing in strength as we move further into this decade, readers need to keep their eyes open for them on future dates. Let us know what you find!</p><p><br /></p><p><i>All photos except those of the 2006 Doubled Die cent are courtesy of John Wexler; 2006 cent images by author. More on the lesser strength 2015 cent doubled dies can be found on John Wexler’s website here:<a href="http://doubleddie.com/228401.html" target="_blank" class="externalLink ProxyLink" data-proxy-href="http://doubleddie.com/228401.html" rel="nofollow">http://doubleddie.com/228401.html</a>.</i></p><p><br /></p><p><i>Ken Potter is co-author of “Strike It Rich With Pocket Change” and has penned many feature articles for “Numismatic News” and for “World Coin News.” He can be contacted via email at<a href="http://koinpro.tripod.com/" target="_blank" class="externalLink ProxyLink" data-proxy-href="http://koinpro.tripod.com/" rel="nofollow">http://koinpro.tripod.com/</a>.</i></p><p><i><br /></i></p><p><i>I just wanted to add that I am thankful for this day and age, We have all the information that is needed right at our finger tips, with full pics and articles for free.</i></p><p><i>Good luck Hunting!</i>[/QUOTE]</p><p><br /></p>
[QUOTE="Pickin and Grinin, post: 2634255, member: 73995"]I was looking for some good reads this morning and clicked on the site that got me started in coin collecting. [url="http://www.conecaonline.org"]www.conecaonline.org[/url] Until this morning I hadn't completely wrapped my head around the Single squeeze hubbing process. I knew that In the olden days they used a reduction lathe. which is why we have the major DDO's 55' 69'S, 70'S 72. The below insert is from Wexlers web site. "The Mint started using reduction lathes in 1836 to transfer designs from a master model (galvano) to the face of a master hub. These reduction lathes were pantographs with two arms. One arm traced out the design on the galvano while the other reduced it proportionately and cut it into the face of the master hub. It was a very slow and tedious process and took anywhere from a day and a half to two days to complete a master hub. [LEFT][IMG]http://www.doubleddie.com/mediac/450_0/media/Janvier$20Reduction$20Lathe.jpg[/IMG][/LEFT] In 1996 the Denver Mint opened its own Die making shop. Introducing the single squeeze press to make master dies.[ATTACH=full]580141[/ATTACH] This was the end of the major DDO or so we thought. You can read the full article written by Ken Potter for Numismatic news on Coneca, below is what he wrote about the single Squeeze process, minus the cool pics. [I][/I] The United States Mint largely replaced the multiple hubbing process in recent years by the “single squeeze” restrained hubbing process. The “single squeeze” process produces doubled dies that are more often than not, restricted to the central areas of the design. The face of a die blank (referred to as a “die block” in Mint jargon) is machined with a slightly conical configuration to aid in the flow of metal during hubbing. This would indicate that the initial kiss of a hub into a die blank would be restricted to this centralized area before continuing on to fill out the rest of the design. During this process the tip of a tilted die blank would be positioned slightly off location away from the center of the hub into a different area of design than intended. After the initial contact, the pressure of the hub would eventually seat the die blank in proper position, and in turn cause doubling on the affected die. (Below referring to 2006, 2014 and 2015 DDO's) These recent-date Lincoln cent doubled dies have been breaking the rule of centralized doubling for reasons unknown. There could be any number of reasons for this but if I had to guess based on seeing more and more of these more “classic looking” obverse doubled dies since about 2010, I’d say that some part of the tooling in the hubbing process for cents has seen some wear resulting in a sloppy fit. This could allow for a shift to occur further along into the process of hubbing a die with the shift occurring at near the finishing point of the dies’ production. No matter the cause, with the Lincoln cent doubled dies increasing in strength as we move further into this decade, readers need to keep their eyes open for them on future dates. Let us know what you find! [I]All photos except those of the 2006 Doubled Die cent are courtesy of John Wexler; 2006 cent images by author. More on the lesser strength 2015 cent doubled dies can be found on John Wexler’s website here:[url]http://doubleddie.com/228401.html[/url].[/I] [I]Ken Potter is co-author of “Strike It Rich With Pocket Change” and has penned many feature articles for “Numismatic News” and for “World Coin News.” He can be contacted via email at[url]http://koinpro.tripod.com/[/url]. I just wanted to add that I am thankful for this day and age, We have all the information that is needed right at our finger tips, with full pics and articles for free. Good luck Hunting![/I][/QUOTE]
Your name or email address:
Do you already have an account?
No, create an account now.
Yes, my password is:
Forgot your password?
Stay logged in
Coin Talk
Home
Forums
>
Coin Forums
>
Error Coins
>
Single squeeze hubbing
>
Home
Home
Quick Links
Search Forums
Recent Activity
Recent Posts
Forums
Forums
Quick Links
Search Forums
Recent Posts
Competitions
Competitions
Quick Links
Competition Index
Rules, Terms & Conditions
Gallery
Gallery
Quick Links
Search Media
New Media
Showcase
Showcase
Quick Links
Search Items
Most Active Members
New Items
Directory
Directory
Quick Links
Directory Home
New Listings
Members
Members
Quick Links
Notable Members
Current Visitors
Recent Activity
New Profile Posts
Sponsors
Menu
Search
Search titles only
Posted by Member:
Separate names with a comma.
Newer Than:
Search this thread only
Search this forum only
Display results as threads
Useful Searches
Recent Posts
More...