To avoid find
Machine Doubling, stop looking at the outside/inside edges of the devices. Look at the centers of the devices. Look for the spread that is seen on a doubled die. If nothing is there, move on to the next coin. The longer you stare at a coin, the more
Machine Doubling you will see. A doubled die is formed on the die.
Note the hub doubling on the date? See the spread of the devices. Now note the yellow arrows altering the coin. All in one direction, flattening the contour on those devices. Note the doubled die affect the letters on the die, but the mintmark is not affected, but is affected on Machine Doubling on both the devices and the mintmark. (A sure sign that a coin is not a doubled die on the pre 1989 coins, as the mintmark is done in a separate step.The machine causes
Machine Doubling. It can also affect doubled dies as well, as the machine damages the devices right after the strike. (In less than a second per strike)