Video from the U.S. Mint for National Coin Week http://www.usmint.gov/kids/cartoons...0160322+News+Release+How+Coins+are+Made+Video
Maybe usmc60 could learn something from this video. Did you happen to notice that nowhere in the coining process was there any mention of machinists doing any of the work? Then again, maybe he will tell us how he had to walk to school 10 miles from the farm every day, uphill both ways. Chris
I must have missed that thread, as I recall no discussion of machinists being involved in the coining process. However, machinists contribute greatly to the production of coinage. Except for the coining dies, machinists make and / or maintain virtually every other piece of tooling used interior to the blanking presses, upsetting mills and coining presses. Upsetting dies, punches, alignment pins, die plates, ejectors, feeding fingers, etc. They're a very busy crew, and certainly far from non-essential in the minting process.
Interesting to see current day technology---but we often look at products that did not have that technology.
Thank you for your input! I raised this issue because one of the other members insists that a machinist is responsible for producing a defective (?) die. However, it is my understanding (as well as others here) that the dies have been produced by computers for many, many years. Here is the quote from another thread....... Would you be kind enough to add your comments? Chris
Master dies may be either engraved or machined, but not by a typical machinist. Each production die is hubbed from a negative impression taken off of an engraved or machined master die. If a machinist error left a flaw on a die, then almost certainly every production die, and thus every coin minted that year, would exhibit the same flaw.
I would think the only thing a machinist would have to do with the dies would be the turning of the die on a lathe in order to form the cone face on the die blank pre-hubbing, and then again to reduce the diameter of the die and neck after hubbing. In the case of the quoted post from another thread, if you left a high spot in the center of the die it would still be pretty much removed during the hubbing process.
Technically, modern day engraving is a machining process, but I would never let a self-proclaimed machinist engrave dies for me. As for the high spot you referred to, I definitely agree . . . an abnormally tall irregularity on a master die would be all but obliterated when making the hubbing die.
I'm going to bump this, because this video should be required viewing for all posters in the so-called error forum. I honestly think that posters in that sub-forum should be administered a (20 question minimum) quiz, and only a passing score will allow posting privileges there.
This video is even more interesting and informative. While it takes place in the Vienna mint, and focuses on special strikes, similar techniques are used here:
