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Spruce

Will this motor/pump work for a press?

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A guy is selling a motor/pump unit on my local craigslist for what seems like a reasonable price, and I think he'll come down.  Here's the link:

 

http://lasvegas.craigslist.org/tls/4155228110.html

 

It's only a 2 hp unit.  Can be 110 or 220 volt.  He doesn't have the flow rates of the pump, but says it originally came off a 40 ton press.  I'm wondering if I can use it for a smaller, say 20 ton press, if it will move the ram fast enough and have enough power.  I ordered the James Batson book, but don't have it yet.  Any thoughts?  The seller is trying to contact the manufacturer of the pump to find out it's flow rates - short of that, is there any convenient method of finding flow?  Just plumb it, and put the outfeed tube into a bucket and see how long it takes to fill up a gallon?  I am pretty new to the trade, and am mostly working on small stuff right now, so I think a 20 ton would be pretty handy.  I realize I could just spend my time swinging a hammer and learning more, but I think I enjoy building tools, jigs, fixtures etc. even more than most projects - I've always been like that for some reason.  Dunno why.  Anyway, thanks in advance,

 

Spruce

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It's only a 2 hp unit. 

There you have it. Gpm's won't matter much because of this. It's likely a high pressure 3000-3500 psi low gpm unit that would be great for a SLOW press used for pressing out bearings. Forging is out of the question.

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force and speed will depend on the bore of the ram used, smaller bore = faster but lower force.

I dont know about there but here there are standard sized pumps, eg size 1, size 2, size 3 and from different makers the pumps are interchangeable mostly and matching specs.

high pressure for me is 10,000 psi ( 700 bar aprox ) I have hand pumps that do that, I have powered pumps from 525 psi ( 35 bar ) to 4,500 psi (300 bar ).

I have a 20 ton steelworker, a 45 ton steelworker and a 30 ton press.

you could get a frame made that takes a fat ram when you want slow but high force and another skinny one for speed.

if you know the bore of the rams and measure the pressure you can work out the force you are getting.

 

if making 2 presses get some quick release couplings for changing hoses over

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Well, if this used to operate a 40 ton press, which is going to have a large diameter bore, my thought is a 20 ton press would move much quicker, yet still be powerful enough for my needs - I don't remember the formulas off the top of my head, so I can't work out exactly how fast it would move, but hopefully once I get that book, I can figure it all out.

 

Correct me if I'm wrong, but horse power does not equal ram speed - ram speed is gallons per minute versus the volume of your ram.  Horsepower is how hard it will push that given amount of fluid.  So the 2 hp doesn't necessarily mean it will be slow - I just need to get a small enough ram, which still has enough power to push that sized ram.  Is this correct?

 

Spruce

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For forging you need speed (gpm) and power. Mine is a 25 ton with a 10 hp mtr and an 11gpm  pump @2500psi  and it pushes a 5in. cyl pdq if I open the diverter valve all the way. When the ram makes contact it doesn't draw the heat out of the piece like a slow press.......let's say I put an air/hyd unit on mine that cranked out 10000psi (not that my cyl could take it). The gpm on those is way less so it would be allot slower and when contact is made with the hot steel even with say 4x the tonnage it would suck out the forging heat before I got it to where I wanted it.....fail.....

Basicly speed (gpm)needs more HP to be effective but high pressure can be achieved easily with  low hp/low gpm units. Cripes, my H press had more tonnage with the hand pump it came with than after the power conversion. But, just try forging with a hand pump unit.. :lol: ...Study the book and get it right the first time.... B)

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Seems like more HP might be needed.  I understand completely that speed is crucial, and that tonnage comes after.  I would still be interested to know the specs on this pump - if it moved a 40 ton press at a high psi but low speed, how quickly is it capable of moving a ram with a much smaller bore?  If you keep reducing the size of the bore, eventually it would move plenty fast.  For example if you plumbed this thing into a ram the size of a syringe, it would move XXXX  fast - obviously a syringe sized ram would be useless, but there is a middle ground.  But basically, if this was plumbed to a 20 ton cylinder, you think it would still be far too slow?  That's about all I needed to know - will wait on building my press for now - and will have the book whenever it ships, and can figure out what specs I need.  Thanks,

 

Spruce

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 But basically, if this was plumbed to a 20 ton cylinder, you think it would still be far too slow?

Nonononono.....I respectfully say tour ignorance is showing.... :rolleyes: :) ......There's NO such thing as a 20 ton cyl. They are rated by bore, stroke and PSI. My 5 in. cyl puts out 25 ton at 2500 psi. If I put in 10,000psi the tonage will be 4x 25 ton. The gpm has no bearing on this.....Also if I put that much pressure to my cast iron cylinder it would likely be my last day on earth............ :(

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Two HP is pretty weak for forging, However I do have a 3hp running a 2 stage at 8gpm low pressure and 2 gpm high. (this is the 16/4gpm pump readily avail on ebay)   It JUST gets the work done in time before cooling the material too badly.  If I'm in a hurry I use one my two ten HP units, one running a 22/6 gpm 2 stage and the other a single stage 18gpm that tops out at 2000 psi.  The single stage pumps *hit* harder than the two stage units.  Get much above 20 gpm and you run into heat issues and the need for bigger valves, resevoirs, etc.

 

I run a variety of cylinders, mostly 5 or 6"

 

Get the $1.50 hydraulic handbook from surpluscenter.com.  All the good hyd info and more

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Thanks for the info fellas - I'll hold off on this unit.  Once I get the book and crunch numbers I'm sure I'll get a better understanding of what I need.

 

Macbruce - I guess I should rephrase my above post to state, "smaller bore cylinder" everywhere instead of just my arbitrary 20 ton number.  But, correct me if I'm wrong, if you take a pump and cylinder setup which is running a larger bore cylinder, and then take off the large cylinder and put on a smaller bore one, all other things remaining the same, it will move the smaller bore cylinder faster, correct?  Or not?  If that is how it works, then you could keep getting a smaller bore cylinder, until you got one which moved fast enough, and then see if it produced enough tonnage (all mathematically of course, if you had all the numbers).  All this is a moot point, because the 2 hp unit will be too small, but in any case, in a nutshell, is that how it will work?

 

Unfortunately, unless a deal floats along in front of my face, I don't think I'm likely to build a press all that soon - got way too much other stuff happening right now.  But, it's fun to think about and plan.

 

Spruce

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Thanks for the info fellas - I'll hold off on this unit.  Once I get the book and crunch numbers I'm sure I'll get a better understanding of what I need.

 

Macbruce - I guess I should rephrase my above post to state, "smaller bore cylinder" everywhere instead of just my arbitrary 20 ton number.  But, correct me if I'm wrong, if you take a pump and cylinder setup which is running a larger bore cylinder, and then take off the large cylinder and put on a smaller bore one, all other things remaining the same, it will move the smaller bore cylinder faster, correct?

Spruce

Faster yes but the reduction in cyl diameter will decrease tonnage.

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Hello all, 

             Have you considered a smaller cylinder with alonger stroke attached to some kind of mechanical advantage, like a first class lever? Alla Ironworker? Hoss Haley built a 100 ton + press with a 3" loooong stroke cylinder by putting the cylinder at the end of a proportionately long lever, and I have it on good authority that thing moves pretty quick ( my friend mike worked with hoss for a few months)He doesn't forge with it but mostly because he doesn't have to. You'd have to make a super beefy frame but steel is cheap and easy to come by, big hydraulic cylinders are not. If'n you look up hoss haley studios on facebook there are pictures of it. 

           As far as speed is concerned, you ca get too fast. I have a 35 to c-frame press with a single stage pump powered by a 7,5 hp motor that moves at between 4.5 and 6 inches a second  which is great......for both ruining work and my day. Even with the limit switches it's just terrifying and dangerous to use. One day I'll build a guide system for the ram and figure out a way to slow it down without getting rid of the pump. 

 

Hope this helps some, take care,matt

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