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 Replies: 7 / Views: 1,054 |
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Pillar of the Community
United States
528 Posts |
I am having a bit of a problem. I am looking up Overton varieties for a few bust halves and a lot of them use measurements for the date stars and other such designs. Well I have a hard time measuring the difference between 8mm and 8.25mm. I am using calipers but I still have a hard time getting the measurements just right.
Anyone have any tips?
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Moderator
 United States
23522 Posts |
Quote:
Anyone have any tips? Not really, but there's a point to that - I've never had to resort to one of those measurements to attribute a Bust Half. The relationship between the T in STATES and the I in PLURIBUS, the D in UNITED and the E from E PLURIBUS..., and the locations of the stars relative to the denticles are enough to attribute 90% of Overton varieties. Most of the rest have unique details in the shield, or the shape and/or location of 50C. There's a reason why these details I mention are listed for almost every single variety. It becomes more difficult for a worn coin, but with that much wear the measurements become useless as well. You'd need significant magnification (probably 20x) to see a difference of 0.25mm anyways. |
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Pillar of the Community
Canada
1931 Posts |
you could buy a medical mouse pad for your computer? I have one that I bought at a first aid stand and it has all the little circles across the bottom of the mousepad and also has a calculator built in. If the coin fits perfectly inside then that's the size. I will try to find a link for you if you would like.
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Pillar of the Community
 United States
528 Posts |
SuperDave is right I guess. I have been doing more and more and I use other things a lot.
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Pillar of the Community
United States
2540 Posts |
I agree with SuperDave.
I have never used those measurements, since they are beyond my abilities to measure.
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Pillar of the Community
Philippines
1156 Posts |
Hi Napoleon31ft!
For the applicaton, we can use a digital vernier caliper, for surface distances, which present readouts straight in number form down to 2 decimal fractional places. Easy to read.
For Depth measurements, (i.e. height of the stars or letters from surface coin plane) suggest also a digital micrometer with a micrometer base vertical stand, the micrometer should have a surface toggle finger (this is usually standard for depth). Adjust stand height then adjust finger on the coin's surface, then on top of the star, measurement readout difference will be the height of the star or letter
These are standard measuring devices commonly used for checking milling and lathe machine works done in overhauling engines. About US$50-100 for the depth gauge. I used to use a japanese brand "mitutoyo" it was all I could afford.
hope this helps
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Bedrock of the Community
United States
17884 Posts |
Forget the measurements. Superdave is right, 80 to 90% of the varieties can be attributed using the positions of the IT and ED relationships he meantioned plus a few other features. I also use the position of the right upright of the last M in UNUM below AM. With those three relationships, and knowing the date, I can attribute about 90% of the varieties. I think you can identify almost all the reverses so the only thing is to identify the Obvs that share a common rev. The position of the 7th star and the headband will separate a lot of those. Then if you still need to, the star positions with the denticals will identify almost everything else. No need to use those measurements.
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Pillar of the Community
United States
1571 Posts |
You could just use overlays, and note the parts that don't conform, compare this, or these to the other varieties, and when they match, you have it.
Dick
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Replies: 7 / Views: 1,054 |
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Posted 08/04/2009 12:12 pm
