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how much press tonage do you need at a minimum to forge with ? i found a deal on a 12 ton air/oil jack and want to know if it will press enough to be efective?

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15 to 20 tons is more than enough for most small shops.  Speed is as important as pressure. If the cylinder isn't double acting then it won't be of much use.

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The work is cooling when it is contact with the dies and the quicker you can cycle the more work you get done.

 

I am not familiar with air/oil so don't know how quickly it retracts. All of the functional presses that I have seen are built on a double acting cylinder.

 

 

 

Press Gallery

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I have aquired a double acting  cylinder and valve.The pump is being rebuilt and I am patiently waiting for it to return .The cylinder is newly rebuilt and was once in service flipping thrash cans into the rear of the truck.Thinking in the lines of speed I hope it will have enough pressure to forge weld. I plan to make the top clevis connector adjustable to allow me to go to a bigger cylinder if need be.Does anyone have any fresh ideas or things they wished they had done in building your press?I have been through the press gallery and will probably copy Don's pretty much.We scrap a lot of plate and beams and material is no problem.I have a few questions on dies I will post later. Thanks

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A few bits about building the press- do NOT shortchange yourself in terms of either motor HP or pump speed. The faster you can cycle the more efficient it will be.

Get a pump which runs at two speeds, fast for low pressure/slow for high. This will enable you to get the power on your press when you need power, but keep it controllable, and at the same time give you the speed when you need it.

A word on cylinders- the "tonnage" rating for cylinders is strictly referring to the max rating and pressure output at a set amount of PSI. You can calculate this the long way, ie, pressure in your system x the area of the bore. Do NOT try to overpower your cylinder, ie, get more press than it is rated for, although most pumps for hydraulics run below this anyhow. As an example, my press has a 30-ton rated cylinder at 3600 PSI, but as my system runs only to 2500 as this is my relief valve setting, it's producing about 2/3 that max, ie, 20 tons. This works fine for welding, forging hot steel etc.

A word of caution- get all your lines, fittings etc done up professionally, and use new parts whenever possible. The risk of old system components cannot be exaggerated- over 20 years working with aircraft equipment has taught me this. Install a gauge so you can see what your system is running at. And have your high-pressure connections facing away from you. High-pressure hydraulic fluid can and will kill you simply by going right through your skin and into your bloodstream- you don't have to ingest it.

Have fun building the press. Don't let all the math work get you down.

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Personally, I feel that a single stage pump that delivers somewhere around 14-18 gpm with an adequate motor of 7.5-10hp will give far superior results as a forging press than will a two-stage, second stages rarely produce more than about 4gpm, and slow dies steal heat.

Although, the two-stage pumps do allow one to get away with a cheaper 5 horse motor and that can be a hard factor to ignore for many.

 

You can go with reletively small ram and pump, say something 12-14gpm on a 4 inch dia cylinder, which won't give mind-boggling power but will have the ram speed... and still plenty of power if you use modestly sized dies, and plenty to weld with in any case.

 

I rarely peak past 20 ton on my press in use, more like 12-15 on a regular basis, but it's fast, if I'm in practice I can run it 2 strokes/second for drawing and flatting and it'll walk all over a 100 pound little giant style hammer on a bad day.

 

Howard's 3B nazel, now, that's another story...

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Thanks for the input . The pump is a single stage. The motor is still in the works.I've even got to get a tank yet. I have thought of making a mobile press .Kinda like some wood splitters I see.In this stage I think of a lot of things and  don't mind asking questions before starting a project.Do you guys have a filter installed in the system?One thing I've noticed is some presses I've seen will have a drip bucket  near.I hate leaks and will use proper fittings throughout the system and seal which connections need it.On dies I saw the squaring die setup and it looks like it would take a pretty good sized billet just to fill the die up with steel.It was Don's die I noticed, I think.I don't fully understand how it works yet.I guess you can design or resize any die  you like.Look foward to having some power for a change.

Randall,About out running the lill giant type hammer You give me optimism for I had thought of building a mech. hammer for a while.You helped me get that temporarily out of mind.Though(a Nazel would be nice huh?)

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Man, I've seen a lot of home-built mechnical hammers at this point, and yet to have seen one that would come anywhere close to the usefullness and ability of even a small press. Or that was terribly safe either, IMO.

 

Someday, I'll have an air hammer sitting beside my press, to have the best of everything, but I've found little that a well-built press couldn't do well, save for driving chisels and sets, which is why I eventually want a hammer too. But the press has worked hard for me and moved ALOT of steel over the years, and if I had to choose between the two I'd lean towards a press pretty seriously.

 

I'd also reccomend you take a long look at the h-frame press designs as well, before you commit to building. The C-frames work fine, but having an open side is not reallly that much of an advantage on a press, like it is with a hammer... I went H-frame and have been very happy with the accuracy, strength, and ease of construction the design affords.

 

If you go c-frame, build it like Don's, big and massive, so it won't flex out so much.

 

Always run a filter on the return line from the valve, on any hydraulic system.

Don't cheap out on cpacity of the resevoir either, a full 5-gallon capacity on a modest press keeps things cool and clean, and with a single stage runs totally awesome....two-stages make a lot of heat so even more capacity isn't a bad thing.

 

Small dies have more jam, big dies spread out the power and have less. For drawing my dies are small and agressive, 2 inch diameter rounds, and will reduce a 1.5 inch bar to 1/4 inch thick in a single stroke without any problem.  Bigger dies I use to weld and flat, and they have less overall power on the material, but that works out perfect for thier use, together, I can take an 8 inch 1.5 inch bar, break it down from round to rough 3/8ths flat, then swap dies and square it all up, in a single heat if I'm totally on the ball. Two heats and it's a done deal, I got a BIG bar of flatstock to go to work with.

 

The press is king for making pattern-welded steel in the under-$3000 tool range.

To get a hammer that'll work better for pattern-welding means you have to look at a serious 200LB air hammer or big mechanical.  If you get a bad billet from your press, it's your fault, not the machines. (which is kinda humbling actually)

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I can take an 8 inch 1.5 inch bar, break it down from round to rough 3/8ths flat, then swap dies and square it all up, in a single heat if I'm totally on the ball. Two heats and it's a done deal, I got a BIG bar of flatstock to go to work with.

 

  That is awesome, I gotta get going on it.Shop I work for has allowed me use of shop and tools .I will be able to weld it with flux core wire.Very tough stuff.Just finished building a 400 ton bulkhead for a dam .Got leftover beam galore. :)

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Hiya, Randal. My 5 hp/2 stage press is still going along good. You may be right about the bigger pump, motor, still the combo does what I want. Igor worked pretty good for you when you came up here. :cool:

I have to support Randal tho when it comes to H-frames. You can make one a lot more compact, and portable, than a C-frame, and being able to run any length between the dies without worrying about the angle helps things. My H-frame is mounted on a cart, when I want to move it for any reason, ie, doing other work in the vicinity, it's no trouble to get out of the way. If you have a smaller sized shop, this can be a big factor. There's no reason an H'frame, even including stand, needs to take up more than 4 square feet or so of floor space.

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Randal and I are on the same page.  My limitation, first ignorance and cheap Northern Hydraulic availability, now choice, is a two stage pump.  That will get changed out with the next evolution of tooling.  However, I'd also encourage the use of a two stage pump system until the press operator's shop practice improves.  As much teaching as I do, having that safety margin is helpful to prevent mistakes that are frustrating in the early learning curve.  With a single stage pump and all that push, it is very possible/likely to over squeeze the billet.  Anyone who's ever made sheet metal when they didn't want to knows what I'm talking about.  

 

The press is my draft horse.  Welding, forging it's a very large big slow hammer (yes, I have a fast cycle time and double acting cylinder.  I did all my forging in one for three years about and never turned on the power hammer.  I like both tools though.  There are somethings you just need the hammer for...

 

And, I have some similar reservations about C-frame systems.  Over-engineering is the minimum standard here whether C or H type.  I use an H-frame and have ####-for-stout ram guides, T-1 wear plate tup and sow blocks with dovetails cut into them for dies.  I like the idea of the moving parts being trapped on both sides front and back with no where to go except up and down.  We still had to beef up the frame with channel iron and more plate because the press would flex everything.  

 

Definitely wheels, most definitely filter and I'd go with a minimum of 7.5 to 10 gallons of fluid, even that tank will get hot in a day's work!  Also consider quick disconnects for hoses so you can use the power plant for other hydraulic projects.  And please consider schedule 80 pipe and fittings for safety.  And, spend the money on hose that has a wire flex safety layer in it or build everything with the hoses overhead.  A dropped hot billet on cheap hose will show you what a high pressure flame thrower is in just over a heartbeat.  

 

I'm looking forward to seeing this bench top model Randal.  I suspect it will need six men and a boy to lift it up to the bench.  Speaking of, I'd better find a bench stiff enough....

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No worries Mike, the power-pack is the bench for the press. Just have it so it breaks down so I can get it in my truck...under construction.

 

You are right about having speed as a beginner being kinda scary, but that can be adressed with a flow valve put in line with the top half of the ram.

 

5 gallons is enough for a 16gpm single-stage, I've never been able to overheat that much, but on a two stage, I agree a little more might be a better thing for sure.

 

I have used some 5 horse two-stages, as Al mentioned I welded a billet in his as well, and they do work just fine. I still think having the single stage though makes for a more versatile and efficient machine though.

Still, it has alot to do with resources too...bigger motor is more expensive, and may not be the way everyone is able to go.

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I'm still at the bottom of the learning curve on presses. What sorts of differences should I look for when considering a press for forging/welding and what I see locally, which is the 2-stage horizontal/vertical log splitter at Lowe's? The only ones that jump out at me are the need for a different shaped ram end (not a point), and for some kind of anvil block underneath it. What else?

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Since everybody is talking about 5 and 10 hp motor's I was wondering how you guys are powering them.  Obviously they are not single phase.  So with it being 3 phase are you buying converter's or did you work out a deal with the electric company and get 3 phase wired to your shop's.  If it is converter's did you have to do major electrical surgery with your panel boxes or what.

 

Just curious, thanks.

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You can actually get single-phase 5 HP motors. I believe 3ph are cheaper, and 5 is about the top end for single phase.

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I have a 2hp single phase that draws 22 amps at 120 and a lot less at 220.  The motors are much cheaper at 3 phase but I don't know the possibilities of getting 3 phase to a home shop.  Has anybody ever looked into this?

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Drat, I had convinced myself that it was perhaps best that my plans to build a H-frame press were put on the back burner in favor of building a better propane forge and a salt pot. Of course the only major components I have collected are a 5"x8" double acting cylinder and a control valve and variuous small asundries like a pressure gauge and a return line filter. The cylinder is new and was a little less than $100.00 at Surplus Center and is rated at 2500 psi. I'm going to have to dig out Batson's instruction manual again I see. I had everything planned out too but now I've got to ponder a single stage pump vs. two stage pump when I thought the two-stage was the better way to go!

 

I can really see the advantage of a single stage in the drawing process. Not plugging it or anything (on second thought I guess I am!) but I would have been utterly lost in learning what little I know of presses without Jim Batson's booklet on building hydraulic presses that I bought through Don's website, that and excellent posts like these on the forums.

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Installing 3-phase power in home shops isn't that uncommon.  My grandfather had it installed twice, (to run two lathes, a milling machine, and all sorts of engineering marvels) and I know a few other engineering types who have upgraded.  Generally I think it's just a question of calling whoever is resonsible for the power supply in your area and asking 'how much?'

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Baldor and Dayton both make single phase motors up to 10 hp.

I just ordered a Dayton 7.5hp for my portable power-pack, 240V single-phase.

around $575.

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Randal, do you mind me asking who you ordered it from? The motor and pump are next on my list to collect. Northern at least seems to have good prices on pumps but I've been all over the place looking for motors (I'm thinking of an 1800 rpm 5 hp single phase motor to run an 8 gpm hi/4gpm lo pump on a 5"x8" cylinder at 2500 psi max). If I did my math right and understood Batson's press booklet I believe that works out to a 24 ton press. I had kinda shelved my press plans for a while but I do want to keep picking up components here and there.

 

Northern Tool has a Leeson single phase 5 hp at 1725 rpm for $399.00 with free shipping on orders over $300.00. I think today is the last day for the free shipping. Here is a link, is this a suitable motor & price?

 

http://www.northerntool.com/webapp....Id=6230

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