Hydraulic press question for guru.

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Dmitry.M

Joined
Jun 13, 2006
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I am in designing progress and have some specific questions. Need answers from people who knows this stuff for real.

I am going to press 3"X3"X3" and make them into the blades for example.

What is better. To have more pressing force or to have dye move faster?
Example - 25tons-1"/sec versus 12tons-2"/sec.
Any optimal values?

Is double stage hydraulic pump any better than one stage one?
I found DS pumps way cheaper than SS. What about the log splitter pump?
I am concerned about their thin drive shaft (1/2")

My calculations shows that to have top peformance I need 45-50HP motor to drive the pump. It is not for the home use obviously and i do not have 220X3phase. does anyone use converters 220-single into 220X3 ?

How do you protect the system from oveloading? Pressure relif valves? Motor current limit?
How do you protect the cylinder in retracted position(for example I released the control too late and high pressure hit the piston)?

How you prefer to assemble the frame, welded or with bolts? Pros\contras?
 
You're gonna have a really hard time stamping blades out of any steel that is 3 inches thick. :confused:
 
My .02:

- for motor, if you need anything more than 3 HP and live in a residential dwelling,
you out of luck as far as electric goes. But, worry not - go for a gas motor instead.
You should be able to score 15HP motor for cheap.

- take a look at log splitter plans - there're some out there. A friend of mine has recently built one from scratch . Of course the design has be to be much stronger for a metal press, but it will provide some basic ideas.

- when working a billet, you don't need to have a full stroke. Assuming you can adjust travel, you won't need to travel more than 4-6"

- surpluscenter.com is a good place to look around

buzzzzzzzzzzz me :)
 
You want a two stage pump. 16/4GPM is great, 13/2GPM works, as will 11/3GPM.
20 tons is good, 26 is great.
5HP electric or 10HP gas. You can get away with 3HP/8HP, fine.
Speed above 1 IPS is nice, but 1 IPS is fine.
The word you want imprinted on your brain when making the frame is, "BEEFY".
Everything on a press is a factor of - motor power in HP:ram diameter in Sq.In. : pump volume in GPM: die size in Sq.In. .....raise one and you affect the others ( sometimes up, sometimes down)

A 5" cylinder operating at 4 GPM will move about 1 IPS, at the 16GPM it moves about 3.5IPS. Quick to get down on the steel, slower and harder to press it.

Force is crucial, though. 12 tons might split oak all day long, but won't do much for 3" steel. 20-26 tons will smash steel.

The most important thing is the die size. The more the surface area in contact with the billet/bar, the more force that is distribute (and the less PSI to the billet).Don't make the dies too big, the plates can be any size, but the die should be limited to no more than 6 Sq. In for a flatting die, and 2 Sq.In. for a drawing die. A piece of 1" round bar makes a great drawing die ( cut it in half and weld half to each die plate). Something tough ,like 4140 or 5160 (JD load shaft) works great.
Stacy
 
Bladsmth - you are the Chosen One! 8)
That was exactly what i needed. Thanks a lot.
So i would have to go for 5" sylinder and a 3HP motor for now, will see than. That shoud produce about a 26ton force with the lack of the speed. I know about the dies and I was planning to have 4sq.in for flatting and aroun 1" round for drawing. Thanks again.
The only questions that remains - where to get the DS pump. I found the good cylinder here: http://stores.daltonhydraulic.com/-strse-441/Welded-Clevis-Prince-Hydraulic/Detail.bok the item number MFG#: DBH-5004-WC
Theu have DS pumps aswell but no data on GPM or pressure:http://stores.daltonhydraulic.com/-strse-Hydraulic-Pumps-cln-2-dsh-Stage-Pumps/Categories.bok
And as I said I am concerned about thin 1/2" shaft on those pumps.

As for the beefy... I was thinking about 1'(one foot) wide I-beam as a side parts and the 1" X5"X16" plates welded as a T-bar for cross bars (4 plates overall) I think it is beefy enough... Moving piece(slide) will be the same T-bar just 5" long with thinner positioning cage. There shoud not be a significant side force for the slide.
 
Rashid11, I am still obessed with wootz. It is for wootz. I just extrapolated the ingot stiffness to the steel piece. The ingot from the very beginning is stiff as hell. And it takes a day to make it maleable. That's why I am going big scale...
 
Dmitry.M said:
I am in designing progress and have some specific questions. Need answers from people who knows this stuff for real.

I am going to press 3"X3"X3" and make them into the blades for example.

What is better. To have more pressing force or to have dye move faster?
Example - 25tons-1"/sec versus 12tons-2"/sec.
Any optimal values?
The whole point of a two-stage pump is that you can have fgast speed and great power.
1 inch per second is plenty for the first stage, when it switches it will be going slower(and believe me this is a good thing)

Is double stage hydraulic pump any better than one stage one?
I found DS pumps way cheaper than SS. What about the log splitter pump?
I am concerned about their thin drive shaft (1/2")
with the stress that shaft is under(low) that pump should last quite awhile(mine is over 15 yrs

My calculations shows that to have top peformance I need 45-50HP motor to drive the pump. It is not for the home use obviously and i do not have 220X3phase. does anyone use converters 220-single into 220X3 ?
I run a 30 ton press at 3000psi and my motor is either a 5 or 7hp I can't remember, so adjust your calculations for a 2 stage pump

How do you protect the system from oveloading? Pressure relif valves? Motor current limit?
Yes you install a pressure relief that dumps the pressure over your limit(mine 3000psi
How do you protect the cylinder in retracted position(for example I released the control too late and high pressure hit the piston)?
I'm not sure what you mean, my cylinder stops at the fully retracted position and no protection is necessary

How you prefer to assemble the frame, welded or with bolts? Pros\contras?
Click to expand...
Presses under 50 ton can be welded, presses over 50 ton should be bolted as welds may fail

I put my answers in bold to easily disquingish them from your questions.
Thanks,
Del
3x3x3" billets are no problem for a 30 ton press or even a 24 ton with careful working. I work this size billet all the time with no problem.
 
Thanks Delbert! It is very good news.
Ok
Now I have another dilemma. I need to convert 220 single into 220-3ph. I found that rotary converters and static converters are almost the same price for the same power capacity.
Static (electronic) ones have a lot of brains inside. And allow to start softly and to limit the torque or the current or almost everything and in any combination.
So what would be your choice?
Rotary - simple and robust.
Static(electronic) - sophisticated but may be not so robust....
I feel I would choose 3HP motor to drive the 2-stage pump... and will choose 16GPM one(do not know the low digit).
 
The pumps are standard. Grainger, Northern,ebay, etc. If you can't find what you want I'll give you some stock/part numbers.

The valve you want is a log splitter type - 3 position,4 way, open center, reverse detent.

The pressure release is built in and usually preset to 2500PSI or 3000PSI.

If you are handy with electronics, hydraulics, and invention, you can build a foot switch powered auto press control that makes the press act sort of like a power hammer.It uses an electronic timer module.
Even if you go with standard controls, investigate a foot operated valve ( It can be as simple as mounting the valve on a board and operating it with your toe).

One good addition is an adjustable detent stop. It is a piece of 1" or larger threaded rod(s) mounted so the ram hits it/them on the return stroke ,and throws out the detent (stops the return). You set it (screw it in or out) so the ram only backs up to a point that allows the billet to be easily inserted. The time saved in travel will allow more hot pressing time.

Don't forget things like filters, water traps,tank magnets, and using metal clad hoses.
Stacy
 
Dmitry.M said:
Thanks Delbert! It is very good news.
Ok
Now I have another dilemma. I need to convert 220 single into 220-3ph. I found that rotary converters and static converters are almost the same price for the same power capacity.
Static (electronic) ones have a lot of brains inside. And allow to start softly and to limit the torque or the current or almost everything and in any combination.
So what would be your choice?
Rotary - simple and robust.
Static(electronic) - sophisticated but may be not so robust.....
Click to expand...

Static phase converters (not much more than a bank of capacitors--not a whole lot of brains) limit you to 2/3 the rated HP of the motor, you do not get full three phase power. Rotary phase converters will allow you to run at full load. Go with the rotary converters.

-Mike-
 
I chose this one for now MFG#: 257-016 from here http://stores.daltonhydraulic.com/-strse-642/16-GPM-Log-splitter/Detail.bok
I am not sure it has a pressure release and they do not specify the lower GPM or max pressure...

Thanks for the detent stop info. I'll use for sure
Foot control is a must. It was in my list and I planned to make a simple extention from hand control down. I am not sure if i will go with the timer or with another detention stop. With lower stop I can set how much I am going to squeese the billet. And for my application it is good.
 
Since no one's mentioned it, you might consider Dr. Batson's hydraulic press manual. It'll easily answer all your questions and more. I think it's available through the ABS website, and may save you time and effort.

Best of luck with the project, Craig
 
While you are at it, you will be using a high volume, relatively, of fluid. Make sure your reservoir is big enough that the fluid doesn't overheat. I run 13 gallons of fluid and have never had an overheating problem. If you use only 2 or 3 gallons, you run the risk. If you are building or otherwise obtaining an unmarked tank, there are 231 cubic inches to the gallon.

Gene
 
The valve will be fine. The pump you listed is good ,too. It is the same as Grainger's #4F664A pump, 16GPM/4GPM. These values are for the pump running at 3600RPM, if you run it at 1800RPM ( check you motor speed) it only develops 8GPM/2GPM (Most pumps flow rates are listed at 3600RPM), and thus the speed of the ram will be reduced by half ( to a little less than 1/2 IPS) NOTE: actual values of a system once set up are about 90% of rated.
What Gene said about tank volume is good advise. Get a large tank.
Stacy
 
I got all my stuff from Northern Hydraulic, including a 5hp Lesson motor. These folks have it all and good prices. My press is an H frame, built from an old set of Batson's plans.

Also check out Don Fogg's site and look at the 'press gallery'
 
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