Making dies
- Thread starter vilts
- Start date
gtsport
Elite Cafe Member
Faster press
Hi Vilts,
That sounds like an OBI (open back incline)press. As long as it isn't free running it should work for coining. Ron Landis at the Gallery mint had several of them along with his screw/fly presses and I watched the OBI press strike copper coins with no trouble. If yours is big enough, you should have no problem.
Joe Paonessa
Hi Vilts,
That sounds like an OBI (open back incline)press. As long as it isn't free running it should work for coining. Ron Landis at the Gallery mint had several of them along with his screw/fly presses and I watched the OBI press strike copper coins with no trouble. If yours is big enough, you should have no problem.
Joe Paonessa
Steve Adams
Elite Cafe Member
- Joined
- Jan 2, 2007
- Messages
- 320
Martin, this thread is getting more interesting all the time. Maybe the coining and die guys should have a forum. Has anyone else out there besides me tried hand hammering into dies? I don't mean hand struck, I mean hammering larger peices of sheet metal into an engraved die. Size is not an issue, and its pretty cool. When I worked in Connecticut for Medallic Art Co. I showed them the process on a six inch bronze plate. They tried doing it in a 750 ton press and couldn't get the design to come up. They at first scratched their heads wondering how a hammer could do something a huge machine could not. Its a long story, but there are very good reasons why some things work and others don't. Tonnage lost out because of thin material and size, and the hammer wins because of multiple impacts in repetitive small areas. I later showed them how to make it work in the press by a formed back striking die.
Martin Strolz
Elite Cafe Member
Ron,
No, in the beginning the flat round copper plate is slightly smaller in diameter than the ring. The collar/ring prevents the copper from being squeezed out sideways during minting. So the pressure is kept within the material causing it to rise into the engraved dies. On the other hand the medal finally sits very firmly in the ring and must be pressed out.
Steve,
Interesting, I never have heard of such a technique. For really high relief medals I use a set of smooth dies to preshape the material. After that first step it actually looks like a lens and must be annealed again before minting. It is also an option to prepare the copper on a lathe.
An example for this below, diameter 1,978 inch, thickness at background ~ 0,123 inch, at highest point 0,222 inch. It is the work of F.Mayr, celebrating his golden wedding anniversary. The plaster model was laser-scanned, I CNC-milled the dies. Mr. Mayr reworked them using hand tools.
No, in the beginning the flat round copper plate is slightly smaller in diameter than the ring. The collar/ring prevents the copper from being squeezed out sideways during minting. So the pressure is kept within the material causing it to rise into the engraved dies. On the other hand the medal finally sits very firmly in the ring and must be pressed out.
Steve,
Interesting, I never have heard of such a technique. For really high relief medals I use a set of smooth dies to preshape the material. After that first step it actually looks like a lens and must be annealed again before minting. It is also an option to prepare the copper on a lathe.
An example for this below, diameter 1,978 inch, thickness at background ~ 0,123 inch, at highest point 0,222 inch. It is the work of F.Mayr, celebrating his golden wedding anniversary. The plaster model was laser-scanned, I CNC-milled the dies. Mr. Mayr reworked them using hand tools.
Attachments
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Medal Mayr.jpg -
Medal Mayr 2.jpg
KCSteve
~ Elite 1000 Member ~
At the KC RenFest there's a guy who strikes coins / medallions. He does silver (which is what I got) and something less expensive (pewter?)
You select the designs for both sides and he loads the dies + blank into his 'press' - it's a post / tree stump about 3 - 4 foot high with pins to hold the loaded dies in place. There are a pair or supports running about 10 - 15 feet up from that. He uses a rope to hoist a fairly heavy weight up to the top, then pulls a quick release. One good solid WHAM! and the coin is struck. It's historically accurate and fun to watch.
I suspect that as long as you stick to something soft you could set a loaded set of dies on a block and hit it with a sledge hammer and get good results.
You select the designs for both sides and he loads the dies + blank into his 'press' - it's a post / tree stump about 3 - 4 foot high with pins to hold the loaded dies in place. There are a pair or supports running about 10 - 15 feet up from that. He uses a rope to hoist a fairly heavy weight up to the top, then pulls a quick release. One good solid WHAM! and the coin is struck. It's historically accurate and fun to watch.
I suspect that as long as you stick to something soft you could set a loaded set of dies on a block and hit it with a sledge hammer and get good results.
garyd
New Member
Good morning all;
I’ve been following this thread with interest as I have it in mind to make dies to produce the medallions that I currently cut on a Gorton model 1D pantograph, by striking them up. Having gotten past the master model learning curve recently, I now know that I can cut my dies in 2D as the design is a simple line drawing surrounded by text (no sculptured form). The first project will be a ¾ inch diameter medallion struck in jewelers bronze. I’d like to present a couple questions here on the matter of die layout, design and fabrication.
Those dies that I have seen pictures of have a conic transition between the engraved face (cylindrical section) and the die (major) O.D. Is this detail necessary and is it necessary for my ¾ inch diameter medallion die that I’ll make from 2 inch O.D. D2 steel. It just seems easier to make the die without the tapered surface and to make the collar to fit the assembly of the two die halves (and collar).
As to material, I am not picky. I do have to solder a pin-back onto the finished medallion so for this reason I do not believe that pewter (nice and soft and easy to strike) will do. Hence the jewelers bronze selection.
I will attempt to strike this up in my 50 ton hydraulic press figuring that well annealed I ought to be able to get an acceptable image as I am not trying to fill a die as it were.
Given the above just how deep should I cut my die for this project? How wide (or narrow) of a line should I produce on the die?
Additionally, are there any general die proportions that I should adhere to? Clearance dimension (fit) of collar to die? Any other avoidable surprises?
Gary
I’ve been following this thread with interest as I have it in mind to make dies to produce the medallions that I currently cut on a Gorton model 1D pantograph, by striking them up. Having gotten past the master model learning curve recently, I now know that I can cut my dies in 2D as the design is a simple line drawing surrounded by text (no sculptured form). The first project will be a ¾ inch diameter medallion struck in jewelers bronze. I’d like to present a couple questions here on the matter of die layout, design and fabrication.
Those dies that I have seen pictures of have a conic transition between the engraved face (cylindrical section) and the die (major) O.D. Is this detail necessary and is it necessary for my ¾ inch diameter medallion die that I’ll make from 2 inch O.D. D2 steel. It just seems easier to make the die without the tapered surface and to make the collar to fit the assembly of the two die halves (and collar).
As to material, I am not picky. I do have to solder a pin-back onto the finished medallion so for this reason I do not believe that pewter (nice and soft and easy to strike) will do. Hence the jewelers bronze selection.
I will attempt to strike this up in my 50 ton hydraulic press figuring that well annealed I ought to be able to get an acceptable image as I am not trying to fill a die as it were.
Given the above just how deep should I cut my die for this project? How wide (or narrow) of a line should I produce on the die?
Additionally, are there any general die proportions that I should adhere to? Clearance dimension (fit) of collar to die? Any other avoidable surprises?
Gary
bartelfitzneel
Member
Using drop hammers to strike coins is as "historically accurate" for a renaissance themed event as a helicopter is. Yes, da Vinci drew pictures of them. But they were never used for production purposes. After the hammer was phased out, and it was phased out over a couple of centuries, they went to flypresses, and some rolling mills. Then came the knuckle press, steam, hydraulics etc etc. Those guys are a franchised business out of california. And their dies are as renaissance like in style, motif and tooling as the press. Swinging a hammer to make coins if much faster than the drop press, so they weren't used. There may have been some counterfiting done with drop hammers, and there still are, but that would be about it.
Those who fail to study history are doomed to repeat it badly.
Fascinating reading! I've never thought much about the process of dies/striking, but after reading this, I have nothing but admiration for those of you who do it.
I would like to make my own hand punch for striking my mark onto silver products. I was going to use water hardenable tool steel (A1?), but you professional die guys would no doubt have an opinion on this matter.
Would someone care to comment on a suitable material, any engraving advice and hardening process?
Perhaps this would be better in a fresh thread?
I would like to make my own hand punch for striking my mark onto silver products. I was going to use water hardenable tool steel (A1?), but you professional die guys would no doubt have an opinion on this matter.
Would someone care to comment on a suitable material, any engraving advice and hardening process?
Perhaps this would be better in a fresh thread?
pappy
Elite Cafe Member
Hi Ozgraver!
If the silver is annealed, and you are only using a simple mark, why not try to use just cold rolled steel, and if this proves too soft, send the punch you made out to a heattreater and have it case hardened. If the mark on the punch is small, only have it hardened to a depth of about .010", that way the letters will have a hard surface, and a tough core. For short runs, it will probably work ok.
If the silver is annealed, and you are only using a simple mark, why not try to use just cold rolled steel, and if this proves too soft, send the punch you made out to a heattreater and have it case hardened. If the mark on the punch is small, only have it hardened to a depth of about .010", that way the letters will have a hard surface, and a tough core. For short runs, it will probably work ok.
pappy
Elite Cafe Member
Let me know how you makeout!
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