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Posted 12/12/2010 5:37 pm
Please forgive my questions as I am still very much confused as to Machine Doubling and die doubling. Everytime I think I have it down, I visit an error website and will come across a verified Doubled Die that looks for all the world like Machine Doubling to my untrained eye.
So to this case in point. My understanding is that Machine Doubling is caused by loose dies that twist slightly after coming into contact with the planchet. Right? Which means that the shelf like image is the original point of contact and the image in relief is the material caught under the die as it moved in the striking process?
I get that the "VDB" is in relief on the die. So it should then strike into the planchet causing the incise image; normally? Correct? So with Machine Doubling once the "VDB" was punched into the planchet for it to be Machine Doubling the die would have to slightly rotate during the striking process; thus either making a wider "VDB" or pushing material UP onto the planchet surface as the die rotates and recedes. Is that correct?
Again forgive me I am trying to approach this from the view of a Machinist.
My greatest confusion arises because in the picture of the "VDB" it APPEARS, to my admittedly untrained eye, that we have two incised sets of letters. Particularly the "V". I would like to have a better picture of the area of the left side of the "V" it looks like you can see the planchet striations in between the left arms of the "V". One striation APPEARS to come from before the "V"; appear in between the left arms of the "V"s and continue on past the that feature. Leading one to believe that the area in between the two "V"s is same level as the surrounding areas of that design feature.
I don't see how you could have two incised images, that result from a shearing/twisting of the die unless it struck twice?
Please understand I am NOT questioning the diagnosis. I am just having a very hard time wrapping my head around this process.
I have worked with dies as a machinist while going to College to get my Engineering Degree; so I am somewhat familiar with the overall process. Admittedly on nothing as small as a coin.
Help!
So to this case in point. My understanding is that Machine Doubling is caused by loose dies that twist slightly after coming into contact with the planchet. Right? Which means that the shelf like image is the original point of contact and the image in relief is the material caught under the die as it moved in the striking process?
I get that the "VDB" is in relief on the die. So it should then strike into the planchet causing the incise image; normally? Correct? So with Machine Doubling once the "VDB" was punched into the planchet for it to be Machine Doubling the die would have to slightly rotate during the striking process; thus either making a wider "VDB" or pushing material UP onto the planchet surface as the die rotates and recedes. Is that correct?
Again forgive me I am trying to approach this from the view of a Machinist.
My greatest confusion arises because in the picture of the "VDB" it APPEARS, to my admittedly untrained eye, that we have two incised sets of letters. Particularly the "V". I would like to have a better picture of the area of the left side of the "V" it looks like you can see the planchet striations in between the left arms of the "V". One striation APPEARS to come from before the "V"; appear in between the left arms of the "V"s and continue on past the that feature. Leading one to believe that the area in between the two "V"s is same level as the surrounding areas of that design feature.
I don't see how you could have two incised images, that result from a shearing/twisting of the die unless it struck twice?
Please understand I am NOT questioning the diagnosis. I am just having a very hard time wrapping my head around this process.
I have worked with dies as a machinist while going to College to get my Engineering Degree; so I am somewhat familiar with the overall process. Admittedly on nothing as small as a coin.
Help!
