General question regarding rotated dies: how much rotation is needed for a coin to be considered a premium value? 45 degrees, 90 degrees? And how do you determine if it's CW or CCW rotation? To post a coin should you use a mirror to show the rotation? Anything else? Thanks in advance for all your replies!
As a generality, you need 90 degrees or better to provoke any real interest, unless rotations are known to be really rare for the issue. The direction of rotation is compared to where the coin should be oriented when you flip it from the obverse appropriately, measured from "straight up and down." When you post it, if you're illustrating rotation, orient the coin exactly as you would if it weren't rotated at all, with the reverse "vertical." Idle note: given that the reverse is usually the anvil die, in the real world it's almost certain that in a rotated coin it was the obverse die which actually rotated.
OK, here's a 1960 Jefferson nickel that I left in the flip as I think the flip helps show the rotation. Let me know if I should take the pictures of the coin out of the flip.
The easiest way to measure the degree of rotation is to mount the coin in a 2x2 mylar flip. Mount the obverse (heads) so that the unopened edge of the flip is at the top (12 o'clock) and make the coin as level as possible in the opening using some horizontal reference such as LIBERTY or the date. Then, you can turn the flip side-to-side to view the reverse (tails). Think of the face of the flip as a clock. Each hourly increment is 30 degrees. Each minute is 6 degrees. Chris
Flip the coin on its' horizontal axis, not its' vertical axis. Just as if you wanted to look at it right side up (as you should).
Going off your instructions, I flipped the wrong way, but cpm9ball already replied with the degree of rotation so do I need to take another set of pictures with the correct flipping method you described?
No, because we can look at the staple locations and determine the actual orientation from them. It's just a whole_lot_easier for everyone whose opinions you're asking for to post coins according to the standards of what's easiest to study - outside any container, and oriented straight up and down (plus any rotation).
And is the rotation direction based on the obverse when saying it's either CW or CCW rotation? Since this coin only has 18 degrees rotation, I'm guessing this isn't such a big deal and the coin would not have any added value/premium as a major error?
On older die setup the die was held in place by set screws. If the hammer die (often the obv) was loose enough to rotate, it also had a tendency to fall out. So usually it was the ANVIL die that came loose and rotated. They still use set screws to hold the dies in place but the also grind a flat on the side of the die so the set screw can't "slide around the die" and let it rotate. But this flat is (or at least was) ground on the die body by hand. Rotate the die slightly and the grind the flat and it is now ground in the wrong location. Even if the set screws are tight and the dies aren't rotating they will still be "rotated" with respect to each other.
You're exactly correct. It might seem picky to have such strict standards for displaying things, but don't forget that numismatics is a pretty exact science. A barely-visible difference in the location of a single die crack could be the difference between a common variety and a brand-new, never-before-seen variety which puts you in the history books. It's always best to make things as clear as your talents and equipment will allow, and if you do your level best in return we'll do our best to help you improve. It's the people who don't want to put the effort in - who don't ask these questions like you are - who end up seeing our....darker side. Ooooh. See how my mind works? I had that precise sequence in mind - knowing the hammer die would fall out if it loosened - and still didn't manage to type what I was actually thinking. Well, it's been hours since I last stuck my foot in my mouth. I'm due.
I'm a vet, airborne ranger to be exact, so I totally understand and adhere to strict standards--it's what separates the best of the best. So in order to classify this minor error (if this even qualifies as an error?) All rotated dies should be called rotated die only and the degree rotation direction should be based on the obverse rotated CW or CCW off top dead center position? If this is the case, then this is what you would then determine the degrees the obverse is off? I hope my questions make sense and that my lack of correct terminology isn't confusing anyone. As always, thanks again for educating me, and hopefully others as well, on the topic of rotated dies!!!
The "accepted use" is to show the reverse as rotated in imaging, with the obverse implied "correctly" straight up and down. As Conder mentioned (I've been interacting with him across multiple fora for more than a decade, and not once have I seen him place a word incorrectly, so when we disagree, he's right ), the reverse is probably what was actually rotated anyway. Doesn't matter which face is rotated in truth, we'll never know for sure. So, it's categorized CW or CCW on the reverse's difference from top dead center, and usually "guesstimated" unless you're obsessive enough to slap a protractor template over the pic to know for sure. Die rotation quite meets the definition of "mint error." Yes, minor in the case of rotations less than 90 degrees, but they intended them to be straight.
Got it and thank you, Condor, and everyone else who imparted their knowledge on my question/topic!!! PS: I'm OCD enough to slap that protractor on and get the exact degree rotation!