Thursday, November 13, 2014

Coin Ring Hole Exactly Centered - Secret Revealed

The very first step towards creating a coin ring from a flat round coin is - you must somehow make a small hole in the center of the coin.

Now you can accomplish this one of two basic methods. You can punch the hole with a punch and die set; or alternatively you can drill a hole in it. Or, I suppose you could punch a small hole and then drill it out to make it larger. In either case, you end up with a hole in the coin which then makes it possible to fit it over the end of a tapered mandrel.

Once you have it started over the end of your mandrel; you can then begin the hammering and folding process. And, this hammering and folding process can go on for quite some time.  At least this is the typical "Hammer and Mandrel Process" you see demonstrated in all kinds of various YouTube videos and other instructional materials on the Internet. (Note: Although this is the typical process you see demonstrated the most; it may not be the only technique for achieving the desired end result...)

However, regardless of how any particular coin ring maker/artist develops their own coin rings; ideally the hole being exactly centered in the geometric center of the coin will produce the most dimensionally perfectly sized and shaped coin ring. That is, the width of the resulting band of metal will be exactly the same around the entire circumference of the finished ring.

Knowing this desire, or requirement, for a perfectly centered starting hole, a few clever entrepreneurs have discovered it might be more lucrative to sell hole punching devices to coin ring makers, than to actually make and sell coin rings. These devices, though cleverly designed and very effective, are extremely expensive (at least I think they are).  Of course they are machined from steel bar stock, and machining costs are not cheap these days.

Well, I promised to reveal the secret of "the exactly centered hole"; and so I shall. There is no denying that producing a coin ring with precisely the same width of band around the entire circumference - does in fact ideally require that the hole be positioned exactly in the center of the coin. However, the secret is; the hole really can be off from exact center and still the coin ring can be fashioned with the same width of band around the entire circumference. Thus, it is entirely fool-hearty to obsess over the task of exactly centering the hole. The reason it is not that important is because the ring maker has at least two separate opportunities to fix an off-center hole before the ring is completed.

The first is done with a round file before the forming process is started. At this point, the maker/artist merely files the off-center hole until it is slightly larger and centered.

The second is done with a flat file after the forming process is completed. The flat file is used on the cut edge to adjust the ring width until it is the same all the way around.

Both of these methods work extremely well - and are obviously a great deal cheaper than investing in expensive machined hole-punching devices.

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