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 Replies: 6 / Views: 1,081 |
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Rest in Peace
United States
5375 Posts |
Is there some kind of device for detecting them, based on balance? I have an 1865-S Half Dime in XF+, which is a pretty scarce coin (and I got a bargain), and I am myself confident from a naked eye assessment that it is not bent, but I would like to have a more reliable way. I typically close one eye to eliminate view of the side of the coin, and examine the edge as I rotate it. It is pretty reliable and I have detected some pretty slight bends that looking at the coin sitting it on a surface wouldn't detect, but I would like even better. I buy a lot of Half Dimes and dimes, so this would help. Thank you in advance. Edited by coinguybrian
07/30/2009 4:58 pm
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Pillar of the Community
Philippines
1156 Posts |
 Had that same problem too, way way back setting clearances for coin slot on vending machines. The applicable professional device would be a comparator, used in machine shops, acts somewhat like a digital projector. Displays item on screen, complete with dimensions, angles and planes. But it is extremely expensive and needs training to operate. What we did was use a 12inch Vernier Caliper, you can see the jaws not setting properly on the dime, obviously a bent situation, but this one is slow, and hard on the eyes for so many coins to do. Or, you can set up a box-light (with a hole). It goes like this: Get a shoe box, reinforce the cover by attaching stiff illustration cardboard on it, the difficult part is cutting out a round hole on the shoebox cover, hole location about 3inches from the short side, it must be fine cut, no frazzled rims, diameter of hole should be 5mm less than the diameter of your coin. That done, darken your room, place a lights-on flashlight inside shoe box, cover it- hole near lighted end, and place your dime to completely cover the hole. If coin is bent, light will leak through the edges creating a shadow, later by experience, you can determine bent type and it's extent by the type of shadow created Hope this helps |
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Bedrock of the Community
United States
20753 Posts |
Cheap easy method is to lay the coin on a clear glass surface. Slowly pour some distilled water around the edges of the coin with an eye dropper. Watch under neath for any water starting to leak under the ocin. If it does rapidly, the coin may be bent. Not perfect but does work.
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Rest in Peace
 United States
5375 Posts |
Ah, that's pretty neat. I don't know if I have any glass tables though : ( Nic, it's a Half Dime, 5 mm smaller would be almost nothing lol. |
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Member
United States
917 Posts |
I like Carls idea , it wouldnt need to be a table , a picture or mirror would do , even a small one.
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Pillar of the Community
United States
581 Posts |
Wow!
I like Nic's answer - although it is a bit impractical for someone like me.
I love it when I read things like his/her post. I don't know. It's kind of like a sneak peak to how it's "supposed" to be done!
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Pillar of the Community
Philippines
1156 Posts |
Oh! a half-dime! if coin is small, you can just punch a 2mm diameter hole, use a thick sewing needle? and just intensify your light. The idea is basically your coin is supposed to block the light, any light coming out must have found a path, which means the coin is bent, or an edge is chipped off. If you really want to get into it, you can start marking the shadow lines on the board,designate the coin orientation point, then use a 12inch vernier caliper to measure thickness delta from coin's standard thickness. From the data you can compute the actual angle of bent from the coin's plane. It's sort of a lab experiment that get's the interest going. Thanks guys for the appreciation  loved it! |
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Replies: 6 / Views: 1,081 |
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Posted 07/30/2009 4:36 pm
