As some here know I have been using a CAD System for many years as a tool for attributing coin varieties. Mainly Lincoln Wheat Cents. During this time I have accumulated a significant amount of data covering an extensive number of varieties in the series. I am not seeking financial gain. I just want to share this information with the coin collecting community. But I do have some problems and questions concerning this data. Although I find this information personally useful – being it was created by me personally – I can not judge the data in an unbiased manner as being truly useful to the coin collecting community. I don’t want to spend a lot of time compiling and providing information people will not use. So maybe ya’ll can help me with this and give me your opinion. I created the data and therefore understand it easily but also realize that although it is based on a simple concept its presentation may be complicated and confusing to others. I want to provide the information in an easily understood format useful to coin collectors with or without a Cad System. I could use your input on this also. The basic concept is as follows. A landmark feature on the mintmark side of a coin is selected for each coin design. Using the precision of a CAD System the location of the mintmark relative to this landmark feature is established and recorded for each die variety. Attached is an image of a Lincoln Cent 1915-D WDDO-001 containing all the CAD construction as an example. The Following is an explanation of the construction of an image imported in my CAD System. The (Y1) axis is established by drawing a line down the edge of the "1" in the date. All construction is draw parallel or perpendicular to this axis except for the Horizon line and the mintmark diagonal. The (Y2) axis is established by drawing a parallel line to the (Y1) axis along the inside most edge of the "9" in the date. The (X) axis is established by drawing a perpendicular line to the (Y1) axis at the lowest point of the "9" in the date. Where this line intersects the (Y1) axis and the (Y2) axis creates Origin 1 and Origin 2. The mintmark is boxed in with lines parallel and perpendicular to the (X) or (Y) axis running through the northern most, eastern most, southern most and western most points of the mintmark. The intersections of these lines create point (A) and point (C). A diagonal line is drawn in the mintmark box connecting point (A) and point (C). Point (B) is established at the midpoint of this diagonal line. The scale equals the distance from origin 1 to origin 2 as measured using the precision of a CAD System. Which equals the width of the "9" in the date. The scale value equals 100%. Using point (C) as an example. The actual distance of the scale in this image is 0.7365 inches. The actual (X) value of point (C) based on origin 1 is 1.2044. (1.2044/0.7365) = 1.6353 or approximately 164% of the scale. From this point forward it doesn’t matter what size image is utilized. The length of the scale may be different but for the Lincoln Cent 1915-D WDDO-001 the (X) coordinate for point (C) based on origin 1 will 164% of the width of the mintmark. And the (Y) coordinate will always 104% of the width of the mintmark. These relative coordinates can be expressed in many different ways computed from many different origins. Take point (A) as an example. Based on origin 2 it is 11% of the width of the mintmark West of the origin which is the same as a (X) coordinate of –11%. With a (Y) coordinate 32% South or –32%. The Horizon Line is created by orienting the image based on the mintmark being straight in the CAD workspace. A line parallel to the workspace itself is drawn. The angle where this Horizon line intersects the (Y) axis is measured using the precision of the CAD tools. On the example provided this angle measured at 93 degrees or as indicated 3-degree rotation to the right. Any angle greater than 90 degrees indicates a mintmark rotation to the right. Any angle less than 90 degrees indicates a mintmark rotation to the left. Anyway as you can see this information can be presented in a plethora of different ways, I just need to know if the coin collecting community would find it useful and if so in what form would it be easiest for people to use. Not only is this information useful in variety collecting – it also can be utilized in counterfeit detecting. The 1909-S VDB was struck by only 4 dies – each with their own unique mintmark location.
By the same token this type of data could also be very useful for counterfeiters to perfect their wares.
I used AutoCAD by Autodesk for many, many years, and one of the things I found is that the proprietary nature of Autodesk products did not allow for a simple import of non-proprietary data. Of course, this may have changed over the last decade. What type of AutoCAD program do you use? Chris
This info could be very useful for identifying die marriages in other series, etc. I'm very interested.
I use TurboCAD purchased many years ago off the shelf from Best Buy. The coordinate data is maintained in an Access Database. Usually just query the database for point (A) in relation to origin 2. It returns a list of varieties for that year sorted from closest to furthest to the coin I am trying to attribute. About 90% of the time the variety will be one of the top 3 on the list and 99% top five. If I can't attribute within the top 10 on the list it is almost always a variety not yet entered into my database. Well for Lincoln Cents anyway. Coin designs where the target area for the mintmark is small and confined - the deviation of mintmark placement is not as significant from die to die. For these rotation and point (B) and point (C) info need to be added to your query.
While in college earning my accounting degree - I worked for a civil engineer surveying land. Did everything from laying out subdivisions to helping build navigable canals. Did a lot of kaiser blade swinging and stretching 100 foot steel chain also.
While I am not delving into the depths of this analysis, if it has anything to do with mintmark placement: A couple of months ago in CoinWorld QDB wrote about the mintmark placement on US 5 cent pieces. He had noticed by eye in hand several different positions, and asked readers to help identify any patterns of such random placement of MMs.
First off, I don't even know what CAD stands for. It seems like you're interested in providing info to as wide an audience as possible. However, this info is very technical, trivial unless someone has a related specific need, etc. So I don't see it getting widespread interest. Maybe first work on developing a summary of what this system is for. Try to convince the average dedicated collector (appealing to a noob would be even harder) why they should give this system some thought and usage.
