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This might be a stupid idea but has anybody ever tried making a forging press using a really big lever?

I’m not great at math or engineering but I wonder  how much force could be generated by a device like the one pictured. 

If you maximize the length of the lever and all the little angles and, if the lever was sufficiently strong, I’m guessing you could get it done.

For those of us who can’t afford a hydraulic press it might offer the opportunity to get a pretty good number of presses per heat.  

 

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I'm no engineer, mpc, but even without a calculator my guess is that Fat Guy in your diagram would need to be 10 or more Fat Guys.  Presses tend to be 20-50 Ton and I'd think it would tend to take a lot of leverage and a lot of weight on the lever to git-er-done.  On a side note, a 5-Ton Wheel Press can do some of the work for you.............but not smashing billets I wouldn't think.

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That’s one of the questions I had. How much force is actually necessary to move the metal enough to draw out a billet? 

If you had a “metal smasher” with a business end that’s about 1/2” x 3,” I wonder what it would take to generate 25 tons. 

I’m aware this may be a stupid question. There’s an old joke that applies to me about law school being the home for people with no capacity for mechanical or mathematical thinking. 

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I know a bunch of smiths have jury-rigged 20 and 30-Ton log splitters into presses that seem to work, but I certainly don't know how one could make a manual version.  I'm neither an engineer nor a lawyer, but fancy myself a reasonable "git-er-done type backyard engineer" and I don't think I'd attempt making a manual press like that.

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11 hours ago, mpc said:

How much force is actually necessary to move the metal enough to draw out a billet?

Blacksmiths and bladesmiths do that on a regular basis with hand held hammers.

Hydraulics and or powered mechanical hammers just make it easier. 

 

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IFI member Ric Furrer noted in a discussion some years back that a hydraulic press needs a minimum of 8 tons per square inch to move hot steel. Let's assume (A) that the distance from the fulcrum to the input (fat guy) is four times the distance from the fulcrum to the ram (metal smasher) and (B) that the latter is one inch square. The force delivered at the ram is going to be four times the input, which means that the fat guy is going to have to weigh two tons in order to deliver sufficient squish. Twenty assistants weighing an average of 200 lbs each would have the same effect (assuming you could get them all applying their weight in the same spot), but for what you'd have to pay them, you'd be better off just buying or making a hydraulic press or a power hammer.

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Not to mention that if you are trying to do this on your own; the lever would need to be so long that by the time to set the piece of hot steel and ran to the end of the lever it would be too cold to work...

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The principle is ok but the fulcrum should be in the middle and rigged so you lift the lever to do work at the other end. A small man can push many times his own weight against the earth to generate more force than a fat guy sitting. Now the question becomes what do you build it out of that is both rigid enough and light enough that you do not loose a great deal of force to the frame flexing. Or to lifting the mass of tge lever. 

By the time you solve all the inherant issues and design problems i bet you could have smithed up enough hooks hammers and blacksmith keychains to simply buy a press. Which will be cheaper than the machiene you are now building. 

Just my 2 cents

 

susan

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21 hours ago, Chris C said:

5-Ton Wheel Press

I've had some success drawing out billets with my small manual fly press.  Not nearly as effective as a rolling mill, power hammer or forging hydraulic press though.  If I were putting together a team to draw out a billet manually I'd just use a striker with a 10# sledge and director.  On my own, a spring fuller and 4 to 6# hammer and a lot of patience, or a well setup treadle hammer  would be my choice.

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I saw this idea in historic olive presses. After crunching the olives between two stones, the pulp was placed under a press very similar to mpc design. The distance from the fulcrum  to the edge of the lever where pressure was applied ("pulled by fat guy") was about 10 times greater than the distance from the fulcrum to the  "metal smasher". The lever was massive, made of wood of course, a whole tree trunk, 400 to 500 mm across. Now, there was no "fat guy pulling" but workers would pile hundreds of kg of stones to reach the desired pressure on the olive pulp to extract liquids. The press was left with this setup for several hours until no more liquid could be  extracted. The point is that all this setup was massive and used in very soft materials like olive pulp and took a lot of time and man power to attain the required pressures. If it would work for smithing most certainly our ancestors would have developed a system to use levers like in mpc design. Compact ways of achieving mechanically these high pressures in small usable spaces and in one effective way are flypresses, eccentric presses, power hammers and such...

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You can develop a lot of force with a ratcheting type arbor press. The general design can be seen on several catalog item type sites. They are expensive to buy and probably a bit complicated to home build.

David

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The problem is speed; presses of any type tend to bleed off heat from the workpiece as they are in contact with it---which cuts down on the forging time per heat. (Forging below the proper temperature range can cause cracking in things like high C metals...)

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