Need help on hydraulic press

"Good" forge welds are not about the compression..... it's all about having the steel at the correct temp/plasticity state. I often tell folks that I can do anything by hand, that I do with the machines..... the only advantage to the machines is reduced labor, and time savings. Way back when I purchased my first forging press, I had to "rob" from our family savings account to do it....and at that time it was a LOT of money, and a considerable leap of faith. As it turned out, within 6 months I had produced/sold enough Damascus stock that I was able to replenish that chunk of money I'd taken, plus some.

The moral of the story being.... there's simply no way that the average person can go out and build or buy ALL of the things you'd like to have for knifemaking. Its a evolutionary thing..... make a knife, sell it, then turn that money around into materials or equipment and make some more knives, and so on. It takes time, planning, and financial discipline to build a knife shop...... of course unless you're independently wealthy..... but where's the fun in that. :)

Also im going to get some steel for Damascus what width and thickness should i get


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As a machine designer I have specified 3000 psi to get the operation time down to an acceptable level in production. I also specified heavy duty hydraulic cylinder, armored hydro lines, and shielded connections. All that drives the cost well beyond what a more moderate pressure would be, even if the cylinder was free. High speed also requires a lot of additional considerations not applicable here. In any case, forging is best done with a hammer or stamping press.
 
would a cylinder from a 10cu.m tipper truck be ok to use for a forging press?

I'm not familiar with specifically what size/type of cylinder is used in that application.... so for any type of answer I'd need to know more about the cylinder.

In general, I always recommend at least a 6" diameter cylinder, with more "stroke" then you think you need. The biggest concern I always have when folks talk of building a forging press is the fact that most simply don't realize the massive forces involved. A forging press endures far more repetitions and stress then presses that are normally used....they need to be built to handle it. Otherwise bad things can easily happen.
 
Ed's spot on. Presses of any type can be dangerous. A for example is a 60 Ton hydraulic forming station we built a few years ago, basically a big press. 8x18" cylinder, with the customers hydraulic system locked out at a lower pressure so the system would actually operate in the 20 ton range, and 0-9" of the stroke length because we knew they would side load it. We engineered the frame with a overall 2:1 (120 ton) safety factor and 4:1 (240 ton) in critical areas. The steel was bought new, certified. Upon our in house stress test, the steel failed around 30 ton. Come to find out our supplier had sold us off-shore made steel, and the Certs they provided were about worthless. We had to re-engineer the whole project and repair and strengthen the failed areas. We do a lot of prototype work and always consider how many possible points of failure a piece of equipment has. Presses are basically a ball of failure. Every weld, every piece of steel, every span, every hose, every fitting could potentially fail and hurt/kill someone, and it needs to be mitigated as best as possible. Trust nothing, do the math and work out what materials are required and then overbuild everything, then overbuild that. In hot forging work, everything should be shielded and protected. A good book to check out is "Hydraulic Forging Press for the Blacksmith" by Randy McDaniel. It contains a lot of good info on how to go about building a safe press.
 
I'm not familiar with specifically what size/type of cylinder is used in that application.... so for any type of answer I'd need to know more about the cylinder.

In general, I always recommend at least a 6" diameter cylinder, with more "stroke" then you think you need. The biggest concern I always have when folks talk of building a forging press is the fact that most simply don't realize the massive forces involved. A forging press endures far more repetitions and stress then presses that are normally used....they need to be built to handle it. Otherwise bad things can easily happen.

How big or beefy is too big or cumbersome, my buddy has (2) 10' lengths of 7'' x 9'' .375 (3/8'') thick tube to his surplus......
 
Personally I would not use "tubing" on a forging press frame. When I rebuilt my old press, that was only 24 tons, I used a 6"x6" "tube" with 1/2" (yes 1/2") wall x 40" long for the base that the bottom die holder/dies sat on, thinking it was way overkill..... and even though it was fully welded on two sides to the main "I" beam structure, that piece of tubing started to compress/wrinkle after a few months. It surprised the heck outta me, but it's one of the reasons I say that you simply cannot "overbuild" a forging press.

How "big" or "cumbersome" is gona be a judgement call of each individual..... With some thought, you can build something really stout, that takes up minimal room. That being said, I likely work a forging press harder then most....it's not uncommon for me to forge on billets that have a starting weight of 30-40lbs.
 
Personally I would not use "tubing" on a forging press frame. When I rebuilt my old press, that was only 24 tons, I used a 6"x6" "tube" with 1/2" (yes 1/2") wall x 40" long for the base that the bottom die holder/dies sat on, thinking it was way overkill..... and even though it was fully welded on two sides to the main "I" beam structure, that piece of tubing started to compress/wrinkle after a few months. It surprised the heck outta me, but it's one of the reasons I say that you simply cannot "overbuild" a forging press.

How "big" or "cumbersome" is gona be a judgement call of each individual..... With some thought, you can build something really stout, that takes up minimal room. That being said, I likely work a forging press harder then most....it's not uncommon for me to forge on billets that have a starting weight of 30-40lbs.

thanks Ed...I figured this would be pretty bulky as well.........Brian Doherty has a nice build going on over on BS forum
 
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