As a coin collector since age 7 I would really like to get one of those coins somehow! It would be totally unique in my collection! One idea to prevent the coin from getting stuck in the die might be to not have the indented rim at all. Just a flat die with raised printing. I think it is getting stuck because the copper is expanding and hitting the round edge of the die.
At Texas Ren Fest, they use a drop hammer. The mint is operated using controlled amounts of accelerated gravity by raising a 150 lb. hammer to a height of 9 feet. The coins set between the two dies are struck with an incredible 40 tons of force!
It's fine steel powder put down in very thin layers and hit with a laser to melt the metal before another layer of powder is added, then they heat the piece up in a furnace until its almost melting to turn it into a solid piece. After that you can just heat treat it like a normal piece of steel to change the crystalline structure inside the metal into a stronger shape. It's a pretty simple process
Since it's getting compressed it works. The largest danger in this king of mold is actually the sides blowing out due to material inside having nowhere to go under high pressure and basically forcing the walls apart. That's theoretically speaking. This particular mold is short enough where i don't think that will be an issue under any pressure. A bunch of seemingly soft materials can be used to shape hard materials given that the forces are applied in the right way. I have used wood molds to shape sheet metal before and have seen stamps that were used to press sand into molds for casting iron. They too were wooden, but with thin metal cladding on the work surface to even out the pressure on the wood and because wood will not hold up to abrasive nature of the sand as well as steel. You can even use liquids to directly form metal. Process of hydroforming is basically inflating a steel envelope like a balloon inside a mold. I believe that is how frame rails for Corvettes are made.
I used to use a 30 ton smashinator to make nameplates. It's called a flywheel punch. Lauri totally needs one. You just have to set the tool depth very carefully, if you get it stuck releasing the pressure can shoot the ball joint cap across the room. We put a hole in a concrete brick withnit once.
Actually a coin being struck is technically the same thing as he’s doing. Two dies press against a blank planchet. They only use the term struck because of how they were made in the old days with a hammer to strike the metal.
@@markiangooley Usually I'd say that the English language is going to shit... But he might not even be native English so I dont wanna imply that ! English could be his second language so perhaps you're jumping the gun a bit. It is concerning that kids cant spell anymore though. Spending more time learning emotes than learning grammar.
I love that at 90 tons of force he says "don't try this at home". So for those of us that have hydraulic presses at home, the limit is 89 tons. Good to know.
Some distant future archeology classroom lecture: "Long ago, there was this civilization of people in the north, they traded purely in denominations of 5 million, and an economy based upon flattening things."
One thing I learned from the local Mint... Coins are normally stamped fast, fast enough that the heat liquifies the surface and helps make a perfect replica. You want a bang.
Came here to make that comment. That would be more like the usual way the make coins. Perhaps not at full force. Also, I am sure Laurie should know how to clean heat-treated copper.
Leonardo da Vinci designed a coin press along sort-of similar principles, though it used gravity rather than hydraulics (or pneumatics). There are a couple of people who travel around to renaissance faires with this preas design. If the Smashinator can deliver enough force, then it should work too.
Hey Lauri, great project. Some suggestions (as if you need them from me)! First, carry on with the annealed copper, then tumble clean or acid etch to restore the bright finish. Next, do not have a cavity in your die (stamping tool). You could turn the die down on the lathe, if you can figure out a way to hold it, then make a steel sleeve. The dies and copper make a sandwich to go in the sleeve, and after pressing you can press the coin and die out through the sleeve. If that doesn’t work with your existing dies, then print some more but with a 5 degree draft angle to make releasing the copper easier. Tumbling the existing dies may give a little draft too. Would love to see a second attempt at this. Your coins will be awesome!
This is similar to how the Spanish struck coins back in the 17th century, except they used silver and a hammer instead of a press. It’s really cool because the dies weren’t always aligned perfectly so you have coins with off center markings
"I just realized that this is the first time that we're hoping that the thing we're crushing doesn't explode." At that point, you know your life is exciting. :)
We did coining on a hydraulic press in the 1990s. It was a 60 ton electric powered press. Would hit pressure relief valve limit, then hand pump slightly beyond that. The coin blank was about 1.5" diameter x .090 thick. Bronze. we annealed with a hand torch, then pressed while still hot. First attempt was an educational experience. We got lots of kudos. Pro Tip: grind and polish coin faces prior to engraving. EVERY detail transfers. Engraving need not be very deep. Refer to previous statement.
Fun fact about coin production in Finland here from Denmark: We stopped making coins and banknotes/bills for our own Danish Crown currency in 2017-2018, and the Danish Crown coins are now all outsourced to be made in Vantaa, Finland by Mint of Finland, while the Danish Crown banknotes/bills are made by Oberthur Fiduciaire SAS in France.
to soften the copper you should heat it to red hot, then you should throw in the cold water, because when copper cool slowly it going harder and when it cool rapidly it going to be soft
Since copper isn't magnetic, you have to heat it up then put it in water to make it good and soft. Its the same with other non-magnetic metals. What you did was actually harden the copper. Its the opposite of steel and iron.
Add more draft angle to sides and text. Before using the die clean up the flat surfaces. You can wrap some emery cloth or sandpaper around a stick or purchase a small polishing stone. To help separate the dies, add some small notches in the side of the dies. Make then big enough to fit whatever you plan on using to separate the parts ( say a screwdriver). You could also try a different brass that's more maleable - you might try what we call 260 brass or cartridge brass. Have fun.
You need to add more relief angle to the 3D parts, and after annealing the copper use some scotchbrite pads to remove the scale off of them before pressing. Coin presses run to much more than 150 tons of force, IIRC up to 1000 tons of force to press a coin, and use very highly polished hard steel dies for the coin, as the slightest imperfections will be reproduced on the coin. Easier to use aluminium for the coins though, soft and will be work hardened by the forming, making is more durable, plus a lot cheaper and less wear on the dies. For the next one make the die in 3 pieces, a top, a middle ring and then a bottom, so at least you can get an end to use to press the finished coin out with suitable soft jaws and some hollow mandrel to hold the ring.
After heating the copper, put it in a bath of citric acid: it will cool it and clean it in a few minutes. Citric acid is very mild (it is used in food production) and available as a powder. Copper work hardens heating and cooling it (even rapidly) softens it.
Have you considered heating the form from the back to release the coin? Also, three piece stamp set. Front face, back face, and outer perimeter ring. Just make sure the front and back plates are thick enough so they can't easily become misaligned.
Hyvä yritys! Lauri, I have a suggestion for you: Please try the same coining process with zinc instead of copper. As you press the zinc, it will make lovely "music" from the twinning of its crystal matrix. After forming your zinc coins, they can be electrolytically coated with pure copper for the sake of their "monetary" appearance. Warm regards to you and Anni from the Commonwealth of Pennsylvania!
The black coating is copper(ii) oxide. It disappears when you have the flame on it, but reappears instantly when the flame is removed and it's exposed to oxygen. You can try dunking it into water so it doesn't get too much black coating. It won't harden like steel does.
The black stuff around the heat treated coin is a layer of copper oxide. You can wash it with acid and it will look even nicer than the non heat treated coin. Most acids should do. I like to use hydrochloric because it is available as a cheap cleaning product everywhere and it works fast. Vinegar would also work but a bit slower. Sulfuric acid works great too.
You need to anneal the copper before presding. To anneal ... heat to red heat then quench fast in clean water. Also tends to clean off a lot of that black oxide, so you have an ocre red soft copper slug to start with. Pressing the coin will work harden it. Then soak it in tartaric acid till it is shiny.
Coin blanks are anealed before being minted and the strike is with impact and then pressure. This ensures the even flow of metal into the die caveties. A coin die set is 3 parts, bottom top and edge. Called a collar die. It helps keep design and coin alignment and imparts a formed, even edge that can be reeded (which is the many lines that run the width lf many coin edges. It was origonally a way to see of people filed gold or silver off of coins as they do. ) or given edge lettering . it may be neccesary to anneal several times. The top die is usually connected to the ram itself and is called the hammer die,becsuse it strikes. the bottom id called the anvile die and is fixed in place with the collar die around it. The blank after preperation like cleaning , and annealing is preformed from a "slug" into a type 2 planchet . and re-annealed. Washed and struck. I am getting into coin collecting and soon startinga virtual coin shop. I deal with coins alot. While im not an expert yet, i do know a great deal of hwo they are made and the alloys used and more. Great video as usual.
you might want to try whole milk or half and half (coffee creamer) as a "mold release agent". The old trick is to use milk when drilling copper... it can make a smelly mess out of the machine if you aren't careful though. Another old story was that a machinist was working on a progressive stamping die (steel parts this time) and was having tearing/galling issues on a deep draw section. He tried all sorts of stuff, and had no success until he accidentally spilled his coffee in the press and hit the button in anger. the creamer worked as a lubricant.
Consider adding draft angles to your die geometry. If the vertical surfaces aren't quite vertical, but taper a few degrees, release is easier. Great work.
The minting presses that make coins actually typically crush the metal blanks quite quickly, and at very high pressure! Perhaps starting with a thinner blank would help? put a tiny hole for the oil to escape on each die piece and then use the tiny hole to blow coin out with air?
Adding some holes on the top and some pins would make ejecting the coin a breeze much like injection molding dies. The trick is to have a perfectly flush plunger pin and really close tolerance on the holes so the material does not get pushed into the hole around the pin. Anealing copper works very nice, so heat it as before, and then sand it a bit, maybe polish it. Soft copper and shiny. Also an ice cube on the coin to get it out might work. Copper has way more contraction with temperature. Also heating the die a bit with a heat gun at 300-400C will increase the chance to loosen it by differential temperature and not destroy the temper of the die.
The raised rim is super important, but I think it is why the coins are getting stuck in the die. Coin blanks already have the raised rim before they are minted. It might be easier to make the coins wider than the stamps.
I finally thought of one! Destroy stuff using vibration. I saw a video of Oobleck standing and crawling around while on top of a metal play being vibrated with sound. Create a plate or a box that vibrates so hard it tears things to pieces.
You should try annealing the copper round stock by heating it up then cut off a coin size, this prevents oxidation and might make it easier to press into a coin
Dude, I just love your channel! It's the best all around! Its just a testimony to people who can't fathom how weak we are without our higher level of thinking
You can control the oxidation that happens when annealing with a barrier flux. A good one can be made by dissolving boric acid in denatured alcohol. You can get both ingredients at most drug stores. As a side-benefit, the flux burns with a pretty green flame. Remaining oxidation can be dealt with by polishing after annealing. A solution of table salt in vinegar is good for stripping the oxide off before polishing.
You need to heat the copper till it glows red. Then either let it cool down in air or quench in water (won't harden unlike steel). Can't you just remove the oxidation with some fine sandpaper/wire brush/buffing wheel?
Yes you can. Thats whats i was going to comment. Just hit it with a wire brush or wheel and that black oxide will come right off. Then sand and buff. It will come out super shiny. I cast things out of copper and copper alloys all the time.
To remove black copper oxide after pressing you can use a chamber with alcohol vapours or acetone vapours or put a coin right into alcohol. But copper should be hot enough for reaction to start. This will immediately reduce copper oxyde to copper metal
Try freezing the die, the copper and steel should shrink at different rates and the coin might fall out. The discoloration from annealing the first coin might come off with some steel wool or a run through a tumbler.
Remove edges of tool and use some kind of hard steel ring instead. if the ring gets stuck press the coin at elevated temperature and it loosens when it cools down.
Heat the copper first then cut it to the size you want. Also there is lube that is specifically for shaping dies that would help with releasing the coin. Perhaps make the die three parts, the two flat faces and a tube that the flat faces can slide into.
Honestly, when thinking about the beyond the press channel and what happened over there, I can understand why that tree spirit guy was so angry. So it is good thing that you took care of that guy before he could do any harm!
Two ways tu improve the copper annealing result. You could heat it in argon gas, or even in steam atmosphere. Or you could polish it before putting it in the press. The oxide layer is probably quite thin, relative to the bulk and sanding it off would not reduce the overall thickness too much. On the other hand, I believe the oxide would peel off also, if you drop the hot piece in water. To my knowledge copper does not harden in that treatment. In cable manufacturing we used to anneal the hard drawn copper wires in vacuum as a batch process, but I do remember we also had a continuous process where moving wire was heated electrically in water steam. And actually, copper work hardens. Happens even in your press, so eventually you may run out of available force. One more observation -- you seemed to have an easy time machining the copper in your lathe, which to me suggest it was not pure copper? Terveiset karanteenista rapakon takaa!
You might try cooling down with liquid nitrogen the "non separating coin". Copper has a higher thermal expansion coefficient than steel. I am not an expert in this at all, but if copper contracts more it might release.
Coin dies are normally highly polished. That would make it easier to remove your coins, but I don't know how feasible that is with 3D printed material.
5:55 "Don't try this at home" Well how can i resist making my own 5M coin using my own hydraulic press thingie and some copper pieces as well as metal heater in my garage Seriously how can i
Probably it would be better to soften the copper in a little bit over way. Make it read hot and then quench it in watter, then try to press it. For such metals and alloys like copper, brass, broze, gold and silver it will cause some significantsoftening, opposite to what it would do with steel.
i read somewhere that copper is more ductile the colder it is - perhaps cooling the copper prior to pressing might make it easier to press. also your forms need to be able to let the copper out of the form more easily and the side walls probably should be at 90% but perhaps "flanged" out a degree or 2 to allow the cooper space to spread out and more easily just fall out of it's form
You should cut the copper smaller in diameter,like 1mm. That way, when it gets crushed,it doesn’t get stuck when it expands in the two halves of the dies.
Have you ever tried to see the internal stress of a clean object as is gets crushed? If you put a light with a polarizing filter going one way behind the object and another polarizing filter 90 degrees rotated in front of the camera the object should turn all rainbow colored and change colors as more stress is added from the pressing
nice vid but there is one thing what a press can't do what a coin stamper can... get the short powerful impact for the stamping done... and you might change the layout of the letters to slightly tapered (so the coin gets out easier as it is not stuck that deep) as well as use some PTFE spray as dry lubricant on the "blank coins" should work a bit better
As a coin collector since age 7 I would really like to get one of those coins somehow! It would be totally unique in my collection! One idea to prevent the coin from getting stuck in the die might be to not have the indented rim at all. Just a flat die with raised printing. I think it is getting stuck because the copper is expanding and hitting the round edge of the die.
You might get some mail soon 😅
@@HydraulicPressChannel I too would love an official HPC coin
I am not unique, it turns out. I too would love to buy one!!
I need one, too!
Numismatics nerds are all here looking for some unique coins!
"Not Bitcoin but thick coin... Ha... Ha... Very good Laurie" -- Best comment EVER
Lauri*
Pretty good.
THICCCCC
@Nobody else but me You must be fun in all the parties you don't even get invited to.
"And that comes to 11.99."
"Yeah. Can I get change for a coin 5,000,000"
"it was a five-mil coin..."
For non-Finns, search 'tonnin seteli' that has subtitles.
"worth 5 millions regular moneys"
This is how I speak english too.. 😄🙉
You will be suprised what "peso" means translated.....
@@christophpoll784 to what language?
@@einienj3281 Spanish, it's what they speak in Mexico.
Reygoolaar.
"Hope the copper turns to coin before this turns to shit" is a great t-shirt idea for you guys!
hope people dont use nordVPN too
YO YO YO, WHAT THE FUCK IS COINS SIMULATOR
You can easily fix the color by giving it a steel-wire brushing.
i was thinking some sort of acid brushed on. Just cause the steel brush would scratch it
Would be more better to anneal it and then polish it before stamping the design in.
Polishing wheel
@@Timothious_Maximus same thought, just anneal the round stock before cutting it and it can be easily polished while on the lathe
At Texas Ren Fest, they use a drop hammer. The mint is operated using controlled amounts of accelerated gravity by raising a 150 lb. hammer to a height of 9 feet. The coins set between the two dies are struck with an incredible 40 tons of force!
I never thought, that 3D-printed metal would be that strong. Absolutely amazing, what you can do today.
What are, these commas
I, totally agree, with, you. It’s, really, amazing.
It's fine steel powder put down in very thin layers and hit with a laser to melt the metal before another layer of powder is added, then they heat the piece up in a furnace until its almost melting to turn it into a solid piece. After that you can just heat treat it like a normal piece of steel to change the crystalline structure inside the metal into a stronger shape. It's a pretty simple process
To-ta-ll-y
Since it's getting compressed it works. The largest danger in this king of mold is actually the sides blowing out due to material inside having nowhere to go under high pressure and basically forcing the walls apart. That's theoretically speaking. This particular mold is short enough where i don't think that will be an issue under any pressure.
A bunch of seemingly soft materials can be used to shape hard materials given that the forces are applied in the right way. I have used wood molds to shape sheet metal before and have seen stamps that were used to press sand into molds for casting iron. They too were wooden, but with thin metal cladding on the work surface to even out the pressure on the wood and because wood will not hold up to abrasive nature of the sand as well as steel.
You can even use liquids to directly form metal. Process of hydroforming is basically inflating a steel envelope like a balloon inside a mold. I believe that is how frame rails for Corvettes are made.
Increase draft angles to improve extraction.
And don’t forget the oil!
Draft angles on all vertical walls, not just the sides. Then again, the text is fairly shallow in this case.
Also put small hole in dye for air extraction
HPC = Hydraulic Press Coin 👍
Of course, coins are struck, not pressed. The Smashinator 5,000,000 would be better!!
Exactly!!
Dr. Doofenshmirts
The pressanator 3000
of course they also use much smaller, thinner metal..
I used to use a 30 ton smashinator to make nameplates. It's called a flywheel punch. Lauri totally needs one. You just have to set the tool depth very carefully, if you get it stuck releasing the pressure can shoot the ball joint cap across the room. We put a hole in a concrete brick withnit once.
Actually a coin being struck is technically the same thing as he’s doing. Two dies press against a blank planchet. They only use the term struck because of how they were made in the old days with a hammer to strike the metal.
"Don't try this at home."
Yeah because my hydraulic press that I definately have in my shed is collecting dust.
Easy--just take it next door.
Why does almost everyone spell “definitely” as “definatly” or “definately”? Oh, well.
@@markiangooley Usually I'd say that the English language is going to shit... But he might not even be native English so I dont wanna imply that ! English could be his second language so perhaps you're jumping the gun a bit. It is concerning that kids cant spell anymore though. Spending more time learning emotes than learning grammar.
Repairing the economy,
One Hydraulic press at a time.
3d printed metal is a game changer - the parts are much stronger than I thought they would be!
Have you looked at the price of a 3D metal printer? STICKER SHOCK!
I love that at 90 tons of force he says "don't try this at home". So for those of us that have hydraulic presses at home, the limit is 89 tons. Good to know.
Don't try at home. So it's ok to try anywhere else!
copper is need quenching for softening, not slowly cooling ^ ^ opposite with the steel
Wikipedia says it doesn't matter
Yup quench is the way to soften non ferris metals.
HPC is now officially a country with its own currency.
I think Leoko would make a good ambassador.
Some distant future archeology classroom lecture: "Long ago, there was this civilization of people in the north, they traded purely in denominations of 5 million, and an economy based upon flattening things."
you should make (and sell) HPC poker chip sets :)
I agree
Maybe you should sell that coin you made online or on EBAY so that people would buy them as a souvenir from HPC.
I was thinking the same thing. Would definitely get one
I'd buy one.
@@hsmallwood40 I'd buy one. I'd buy t we and give to my dad because watches this channel too
Honestly youre the best at making even advertising engaging. The only time i dont skip trough.
True, neither did I 😄
One thing I learned from the local Mint... Coins are normally stamped fast, fast enough that the heat liquifies the surface and helps make a perfect replica. You want a bang.
did you try the smashinator 5M to "stamp" rather than press the coin, would there be much difference around the same pressures?
yep.. the smashinator would stamp those coins like a champ ! ;)
Came here to make that comment. That would be more like the usual way the make coins. Perhaps not at full force.
Also, I am sure Laurie should know how to clean heat-treated copper.
That would be much closer to the way coins are "struck" between dies by a hammer.
Leonardo da Vinci designed a coin press along sort-of similar principles, though it used gravity rather than hydraulics (or pneumatics). There are a couple of people who travel around to renaissance faires with this preas design. If the Smashinator can deliver enough force, then it should work too.
The Smashinator might break the die
"Hey! It didn't explode!" 6:09 :-D
only shooting stars break the mold
Hey Lauri, great project. Some suggestions (as if you need them from me)! First, carry on with the annealed copper, then tumble clean or acid etch to restore the bright finish. Next, do not have a cavity in your die (stamping tool). You could turn the die down on the lathe, if you can figure out a way to hold it, then make a steel sleeve. The dies and copper make a sandwich to go in the sleeve, and after pressing you can press the coin and die out through the sleeve. If that doesn’t work with your existing dies, then print some more but with a 5 degree draft angle to make releasing the copper easier. Tumbling the existing dies may give a little draft too. Would love to see a second attempt at this. Your coins will be awesome!
Hei, no explosion!
I like the universal use of the Coin 5,000,000. Worth 5,000,000 monies.
This is similar to how the Spanish struck coins back in the 17th century, except they used silver and a hammer instead of a press. It’s really cool because the dies weren’t always aligned perfectly so you have coins with off center markings
make a hydraulic press exclusive coin giveaway xD
"I just realized that this is the first time that we're hoping that the thing we're crushing doesn't explode." At that point, you know your life is exciting. :)
Also maybe freezing the stuck one will get it loose.
To remove the stuck coin, add some heat or cold.
Wikipedia say: Freeze it!
@@boring7823 Yes. Definitely freeze it. Copper expands more then steel when heated I think so should shrink more when frozen I think.
Now try the super high speed Smashinator press.
We did coining on a hydraulic press in the 1990s. It was a 60 ton electric powered press. Would hit pressure relief valve limit, then hand pump slightly beyond that. The coin blank was about 1.5" diameter x .090 thick. Bronze. we annealed with a hand torch, then pressed while still hot. First attempt was an educational experience. We got lots of kudos. Pro Tip: grind and polish coin faces prior to engraving. EVERY detail transfers. Engraving need not be very deep. Refer to previous statement.
Fun fact about coin production in Finland here from Denmark: We stopped making coins and banknotes/bills for our own Danish Crown currency in 2017-2018, and the Danish Crown coins are now all outsourced to be made in Vantaa, Finland by Mint of Finland, while the Danish Crown banknotes/bills are made by Oberthur Fiduciaire SAS in France.
to soften the copper you should heat it to red hot, then you should throw in the cold water, because when copper cool slowly it going harder and when it cool rapidly it going to be soft
Since copper isn't magnetic, you have to heat it up then put it in water to make it good and soft. Its the same with other non-magnetic metals. What you did was actually harden the copper. Its the opposite of steel and iron.
Nifty! Needs draft angles so the coins don't get stuck. Then try extracting the coins with liquid nitrogen or heat.
Add more draft angle to sides and text. Before using the die clean up the flat surfaces. You can wrap some emery cloth or sandpaper around a stick or purchase a small polishing stone. To help separate the dies, add some small notches in the side of the dies. Make then big enough to fit whatever you plan on using to separate the parts ( say a screwdriver). You could also try a different brass that's more maleable - you might try what we call 260 brass or cartridge brass.
Have fun.
And that comes to 11.99."
"Yeah. Can I get change for a coin 5,000,000"
You need to add more relief angle to the 3D parts, and after annealing the copper use some scotchbrite pads to remove the scale off of them before pressing. Coin presses run to much more than 150 tons of force, IIRC up to 1000 tons of force to press a coin, and use very highly polished hard steel dies for the coin, as the slightest imperfections will be reproduced on the coin. Easier to use aluminium for the coins though, soft and will be work hardened by the forming, making is more durable, plus a lot cheaper and less wear on the dies.
For the next one make the die in 3 pieces, a top, a middle ring and then a bottom, so at least you can get an end to use to press the finished coin out with suitable soft jaws and some hollow mandrel to hold the ring.
Good insight, I hope they read your comment.
After heating the copper, put it in a bath of citric acid: it will cool it and clean it in a few minutes. Citric acid is very mild (it is used in food production) and available as a powder. Copper work hardens heating and cooling it (even rapidly) softens it.
Have you considered heating the form from the back to release the coin? Also, three piece stamp set. Front face, back face, and outer perimeter ring. Just make sure the front and back plates are thick enough so they can't easily become misaligned.
You always keeps us entertained
Hyvä yritys! Lauri, I have a suggestion for you: Please try the same coining process with zinc instead of copper. As you press the zinc, it will make lovely "music" from the twinning of its crystal matrix. After forming your zinc coins, they can be electrolytically coated with pure copper for the sake of their "monetary" appearance. Warm regards to you and Anni from the Commonwealth of Pennsylvania!
The black coating is copper(ii) oxide. It disappears when you have the flame on it, but reappears instantly when the flame is removed and it's exposed to oxygen. You can try dunking it into water so it doesn't get too much black coating. It won't harden like steel does.
The black stuff around the heat treated coin is a layer of copper oxide. You can wash it with acid and it will look even nicer than the non heat treated coin. Most acids should do. I like to use hydrochloric because it is available as a cheap cleaning product everywhere and it works fast. Vinegar would also work but a bit slower. Sulfuric acid works great too.
anytime anybody or company says "military grade protection" I have to laugh! I worked for the military for 10 years...
The "best protection by the lowest bidder"
Very clever filmmaking for your sponsor segment!
Just soak the tarnished coin in vinegar overnight, it will look great. Great Video guys!
Good job turning the Forest Spirit into the Couch From Hell.
Wait, you can make things with the hydraulic press instead of just destroying them?!?
2nd_place Mind blow.
You need to anneal the copper before presding. To anneal ... heat to red heat then quench fast in clean water. Also tends to clean off a lot of that black oxide, so you have an ocre red soft copper slug to start with. Pressing the coin will work harden it. Then soak it in tartaric acid till it is shiny.
Ahh my brother, another great fun video, still the very best on TH-cam, keep them coming. Cheers from Australia
HPC autonomous zone with its own money!
Coin blanks are anealed before being minted and the strike is with impact and then pressure. This ensures the even flow of metal into the die caveties. A coin die set is 3 parts, bottom top and edge. Called a collar die. It helps keep design and coin alignment and imparts a formed, even edge that can be reeded (which is the many lines that run the width lf many coin edges. It was origonally a way to see of people filed gold or silver off of coins as they do. ) or given edge lettering . it may be neccesary to anneal several times. The top die is usually connected to the ram itself and is called the hammer die,becsuse it strikes. the bottom id called the anvile die and is fixed in place with the collar die around it. The blank after preperation like cleaning , and annealing is preformed from a "slug" into a type 2 planchet . and re-annealed. Washed and struck. I am getting into coin collecting and soon startinga virtual coin shop. I deal with coins alot. While im not an expert yet, i do know a great deal of hwo they are made and the alloys used and more. Great video as usual.
you might want to try whole milk or half and half (coffee creamer) as a "mold release agent". The old trick is to use milk when drilling copper... it can make a smelly mess out of the machine if you aren't careful though. Another old story was that a machinist was working on a progressive stamping die (steel parts this time) and was having tearing/galling issues on a deep draw section. He tried all sorts of stuff, and had no success until he accidentally spilled his coffee in the press and hit the button in anger. the creamer worked as a lubricant.
Consider adding draft angles to your die geometry. If the vertical surfaces aren't quite vertical, but taper a few degrees, release is easier.
Great work.
The minting presses that make coins actually typically crush the metal blanks quite quickly, and at very high pressure! Perhaps starting with a thinner blank would help? put a tiny hole for the oil to escape on each die piece and then use the tiny hole to blow coin out with air?
5:52 "Don't try this at home"
Oh, ok, I will save my 90 ton force hydraulic press that I have in my home for another opportunity then
Try heating the copper to cherry red, then quench it in water. It will be very soft and the water removes most of the black coating on the copper.
ahahaha "accidently exploded" the tree, good stuff!
Adding some holes on the top and some pins would make ejecting the coin a breeze much like injection molding dies. The trick is to have a perfectly flush plunger pin and really close tolerance on the holes so the material does not get pushed into the hole around the pin.
Anealing copper works very nice, so heat it as before, and then sand it a bit, maybe polish it. Soft copper and shiny.
Also an ice cube on the coin to get it out might work. Copper has way more contraction with temperature. Also heating the die a bit with a heat gun at 300-400C will increase the chance to loosen it by differential temperature and not destroy the temper of the die.
Idea: Put pasta dough in the string presser to make spaghetti.
A while back they pressed coins into a chunk of copper. Now they are pressing chunks of copper into coins.
He just says "Don't try this at home" just like if everybody got a 150 tons hydrolic press in their kitchen haha
The raised rim is super important, but I think it is why the coins are getting stuck in the die. Coin blanks already have the raised rim before they are minted. It might be easier to make the coins wider than the stamps.
I finally thought of one! Destroy stuff using vibration. I saw a video of Oobleck standing and crawling around while on top of a metal play being vibrated with sound. Create a plate or a box that vibrates so hard it tears things to pieces.
You should try annealing the copper round stock by heating it up then cut off a coin size, this prevents oxidation and might make it easier to press into a coin
Smash-in-a-tor! Smash-in-a-tor! Smash-in-a-tor! Smash-in-a-tor! Smash-in-a-tor! (crowd chanting)
9:20 Am I the only one who got frightened of that laughter?! (Sorry for bad english)
Lauri - you also can make knurling on a coin by the lathe. Only need to thick it in between two bit smaller diameter surfaces.
Dude, I just love your channel! It's the best all around! Its just a testimony to people who can't fathom how weak we are without our higher level of thinking
You can control the oxidation that happens when annealing with a barrier flux. A good one can be made by dissolving boric acid in denatured alcohol. You can get both ingredients at most drug stores. As a side-benefit, the flux burns with a pretty green flame. Remaining oxidation can be dealt with by polishing after annealing. A solution of table salt in vinegar is good for stripping the oxide off before polishing.
Next you should try striking the coins with the Smashinator. No heating should be necessary! I wonder if the dies would survive.
You need to heat the copper till it glows red. Then either let it cool down in air or quench in water (won't harden unlike steel). Can't you just remove the oxidation with some fine sandpaper/wire brush/buffing wheel?
Yes you can. Thats whats i was going to comment. Just hit it with a wire brush or wheel and that black oxide will come right off. Then sand and buff. It will come out super shiny. I cast things out of copper and copper alloys all the time.
To remove black copper oxide after pressing you can use a chamber with alcohol vapours or acetone vapours or put a coin right into alcohol. But copper should be hot enough for reaction to start. This will immediately reduce copper oxyde to copper metal
Great watching
This is how all Finnish coins are minted
I like the tree monster at the end. Very nice!
Try freezing the die, the copper and steel should shrink at different rates and the coin might fall out. The discoloration from annealing the first coin might come off with some steel wool or a run through a tumbler.
Anneal the copper (quench it in water) to make it really soft. 👍
Remove edges of tool and use some kind of hard steel ring instead. if the ring gets stuck press the coin at elevated temperature and it loosens when it cools down.
Reminds me of old school pog slammers.
Heat the copper first then cut it to the size you want. Also there is lube that is specifically for shaping dies that would help with releasing the coin. Perhaps make the die three parts, the two flat faces and a tube that the flat faces can slide into.
Your tools are worth more than my entire wealth lol
Honestly, when thinking about the beyond the press channel and what happened over there, I can understand why that tree spirit guy was so angry. So it is good thing that you took care of that guy before he could do any harm!
Two ways tu improve the copper annealing result. You could heat it in argon gas, or even in steam atmosphere. Or you could polish it before putting it in the press. The oxide layer is probably quite thin, relative to the bulk and sanding it off would not reduce the overall thickness too much. On the other hand, I believe the oxide would peel off also, if you drop the hot piece in water. To my knowledge copper does not harden in that treatment. In cable manufacturing we used to anneal the hard drawn copper wires in vacuum as a batch process, but I do remember we also had a continuous process where moving wire was heated electrically in water steam. And actually, copper work hardens. Happens even in your press, so eventually you may run out of available force.
One more observation -- you seemed to have an easy time machining the copper in your lathe, which to me suggest it was not pure copper?
Terveiset karanteenista rapakon takaa!
You might try cooling down with liquid nitrogen the "non separating coin". Copper has a higher thermal expansion coefficient than steel.
I am not an expert in this at all, but if copper contracts more it might release.
Heat them up to 1000 degrees, then quench them in liquid nitrogen. And make a video of it.
I saw a video this week about how they make Euro coins. Same principle, but they used 160tons to stamp the coins.
If you want a shiny coin after heating the blank, Just polish it after you heat it. Brass polish or Ultra fine steel wool. Then try pressing it.
Coin dies are normally highly polished. That would make it easier to remove your coins, but I don't know how feasible that is with 3D printed material.
Wow! it never made sense before but I now know what a VPN service is. great explanation!
5:55
"Don't try this at home"
Well how can i resist making my own 5M coin using my own hydraulic press thingie and some copper pieces as well as metal heater in my garage
Seriously how can i
Heat the copper and quench in water immediately. It will be very soft.
Probably it would be better to soften the copper in a little bit over way. Make it read hot and then quench it in watter, then try to press it. For such metals and alloys like copper, brass, broze, gold and silver it will cause some significantsoftening, opposite to what it would do with steel.
wow, amazing experiment bro
i read somewhere that copper is more ductile the colder it is - perhaps cooling the copper prior to pressing might make it easier to press. also your forms need to be able to let the copper out of the form more easily and the side walls probably should be at 90% but perhaps "flanged" out a degree or 2 to allow the cooper space to spread out and more easily just fall out of it's form
You should cut the copper smaller in diameter,like 1mm.
That way, when it gets crushed,it doesn’t get stuck when it expands in the two halves of the dies.
Have you ever tried to see the internal stress of a clean object as is gets crushed? If you put a light with a polarizing filter going one way behind the object and another polarizing filter 90 degrees rotated in front of the camera the object should turn all rainbow colored and change colors as more stress is added from the pressing
nice vid but there is one thing what a press can't do what a coin stamper can... get the short powerful impact for the stamping done...
and you might change the layout of the letters to slightly tapered (so the coin gets out easier as it is not stuck that deep) as well as use some PTFE spray as dry lubricant on the "blank coins"
should work a bit better