Die rotation gauge

longtimecollector · September 19, 2006 2:44AM

Found this link......

Thought it might help some newer folks understand die rotation nomenclature.

link-a-dink

It says for seated dimes, but it will work for any coin.

MICHAELDIXON · March 19, 2015 11:03AM

From 2006, but the link is still active.

Unknown · March 19, 2015 11:38AM

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ebaybuyer · March 19, 2015 2:26PM

we can thank one of our own for this, Jason is very knowledgeable on rotated reverses of all seated denominations, not a guy that claims to know something, he actually does know something

astrorat · March 19, 2015 9:17PM

Leroy Van Allen sold a very hand device, called a Rota Flip, that was excellent for measuring rotated dies. It was invaluable when John and I were measuring rotated dies on double dimes. Mine is packed away. but here is some info I found on the webernet:

Image of Rota Flip

Instructions

These used to pop up occasionally on eBay or from variety dealers, but I have not seen them for a while.

MrHalfDime · March 19, 2015 10:01PM

A few years ago I published a short article on rotated die varieties in the Liberty Seated half dime series in the E-Gobrecht journal. That article included details of the Rota-Die device and of Leroy Van Allen's Rota Flip, which may prove valuable to some readers. The article appears here:

ROTATED DIE EXAMPLES OF LIBERTY SEATED HALF DIMES

Well beyond the typical pursuit of ‘perfect’ examples of the engraver’s art, many collectors enjoy seeking examples which demonstrate how things could, and often did, go wrong during the coining process. Among the many classes of these ‘error’ coins are those with ‘rotated dies’, or coins which do not exhibit the normal coin rotation of 180° of the obverse die relative to the reverse die. While some United States coin series have very few examples of these rotated dies, the Liberty Seated half dimes are replete with numerous examples. John McCloskey wrote a short article on rotated dies within the Liberty Seated series in the Gobrecht Journal in July of 1977 (Volume 3, Issue 9), listing the few examples of which he was aware, and asking others to submit information on additional examples. Unfortunately, few, if any, other examples were subsequently reported in the Journal. While this may indicate that few collectors care about or actively pursue this class of error coins, I’d sooner believe that collectors merely neglected to take the time to write back to John, reporting other examples they had seen. Perhaps, given the simplicity and immediacy of this electronic medium, we might try once again to determine what examples collectors have seen.

There are various means used to describe the amount of rotation observed, and several methods used to actually measure the amount of rotation. It is quite common to see collectors refer to this class of error as “Rotated Reverse” coins, assuming that the obverse always has the proper rotation when observed, and that only the reverse die exhibits rotation relative to the obverse. Of course, there is no way to know which die was, in fact, rotated incorrectly from the norm in the coining press; we can only describe the ‘relative’ rotation, obverse-to-reverse. Others describe the amount of deviation, in degrees, always assuming a clockwise rotation. Again, there is no standard here, and clockwise rotation of greater than 180° can also be described as counter-clockwise rotation of less than 180°. Additionally, many prefer to specify a minimum rotation, say 10°, ignoring examples of less than that amount of rotation.

Some researchers have described examples of this class of rotated die error in vague and ambiguous terms, using phrases like “upset reverse” or “reverse rotated one quarter turn”. It is usually better to be a bit more specific, by actually measuring the amount of relative rotation between the dies. Most collectors, using only the unaided eye, are unable to specify rotations more accurately than ‘one-quarter turn’ (90°), or perhaps ‘one-eighth turn’ (45°). Two similar devices have been manufactured over the years to enable more accurate measurement of the relative rotation of the dies. The “Rota Die” device was comprised of three sandwiched layers of clear Plexiglas®, with the middle layer cut with a “V” slot. The coin was inserted into the Rota Die device, into the self-centering V-slot, and turned until the obverse die was properly aligned upright. The device was then turned around, and the amount of rotation of the reverse die could be read directly from the back of the device, which incorporated a protractor graduated in degrees. Unfortunately, the ‘Rota Die’ device is no longer manufactured, and is rarely available in the after market. A similar device is manufactured by Leroy Van Allen, well known in silver dollar circles. His device (‘Rota Flip’) is very similar, but is constructed of a soft vinyl plastic fold-over piece that envelops the coin. Then, another vinyl piece is placed over the first, held merely by static electricity, which allows direct reading of the rotation of the reverse die relative to the obverse. One significant advantage of this device over the ‘Rota Die’ is that measurements may be taken on coins while still in any type of holder, whether it be a slab, cardboard 2”x 2” or other holder; the Rota Die required that the coin be ‘raw’ in order to be inserted into the device.

For some rotated die errors, the dies were placed into the coining press and secured using set screws, and the relative rotation of the dies, no matter how incorrect, remained the same for the entire press run. Other rotated die errors indicate that one of the dies (presumably the reverse, or anvil, die) was loose in the coin press, and rotated randomly at each successive striking, resulting in many different rotations for the same die marriage. An example of such a rotated die error would be the 1839-O V3, for which examples are known with all possible degrees of rotation. The loose die almost had to be the reverse die, since if the obverse, or hammer, die were loose, it would likely fall out due to gravity, whereas a loose reverse (anvil) die would remain in the press. Most rotated die errors for the half dimes exhibit the same rotation on all known examples, indicating that the dies were incorrectly oriented in the initial set up of the press, and remained that way.

Examples of rotated die errors for the Liberty Seated half dimes include:

1837 Large Date V1 “Slightly CW”
1837 Small Date V5 24° CW
1838 V8 30° CW
1839-O V3 All rotations seen
1840-O No Drapery V8 20° CCW
1841 “Slightly CCW”
1844-O V2 180°
1845 Shattered Reverse 20° CCW
1847 “Slightly CCW”
1848 Large Date V1 15° CCW
1848 1848/7/6 V7a 20° CCW (Sometimes called V10)
1848 Far Right Date V9 “Slightly CW”
1848-O V2 “Slightly CW”
1848-O V5 20° CCW
1850-O Large O 30°CCW (Appears to be very rare)
1850-O V4 Small O 18° CCW
1853-O With Arrows 20° CCW
1853-O With Arrows 90° CW (Added 8-8-07)
1854 25° CCW
1854 30° CCW (Same variety as above?)
1854 40° CCW (Same variety as above?)
1854 50° CCW (Same variety as above?)
1854-O With Arrows 70° CCW (Purchased 7-7-12)
1856 100° CCW
1856 180° (Same variety as above?)
1857 20° CCW
1857 20° CW
1857 30° CCW
1857 45° CCW (Same variety as above?)
1857 V1 Unretouched Hub 170° CW (Sometimes referred to as V10)
1860 ~60° CW (Added 3-21-10)
1861 170° CW
1862 40° CCW
1865 V1 45° CW
1872-S MM Above Bow 15° CW
1873-S V2 30° CCW

What others have you seen?

Unknown · March 20, 2015 12:39AM

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ricko · March 20, 2015 1:14AM

Nice little guage.... I suspect only needed if one were selling the coin, since rotation can be easily 'ball parked' without a tool....Cheers, RickO

Unknown · March 20, 2015 1:17AM

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Die rotation gauge

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