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coyotedown
04-26-2010, 11:37 AM
Hi

Can you tell me what you think the requirements for a good hydraulic press are? I am meaning size of cylinder, size of shaft, length of stroke, what size motor(will 110 work or will you need bigger),tonnage, and anything else that would be good to know? Pictures of your presses would be great to see.

Thank you,

JAWilliams
04-26-2010, 12:00 PM
Well I can tell you this. 20 tons or more.

Billy Helton
04-26-2010, 01:01 PM
'Well Im goin to tell you what mine is . I have a 5" bore with a 16" stroke and a 2" polished rod size,most use a 8 to 10" stroke. I run a five horse motor 3450 RPM. The pump is a 13 GPM pump. I also went with a H beam design.It is rated at 30 ton at 3000 psi but I only run it at 2200 psi, figured that gives me some wiggle room on saftey.

EdCaffreyMS
04-26-2010, 03:15 PM
All of the things that Billy said with the following exceptions:

-Minimum 6" dia cylinder (the larger the diameter the lower pressure required on the hydraulic lines)

-Build in an adjustable "by-pass" valve, that is pressure adjustable...meaning that you can adjust the valve to by-pass when a specific line pressure is reached.

- For a hydraulic forging press, build the thing 2X more beefed up than you think it needs to be....and then build it some more!

When I built my last press, I used a 12" "I" beam with 1/2" flanges and a 5/8" thick web....and I still had to add 3/8" gusset plates between the flanges to keep it from flexing during use. (Mine is a "C" frame design....I just like them better, and they have a small footprint than an "H" frame press)

One thing that scares the daylights out of me is when I go into someone's shop and they are running a small diameter cylinder on a press (5" or less), and are running line pressures 3,000psi +! If one of those lines gets even a pin hole in it at that pressure....it will cut you in half like a laser! (Most hydraulic lines are only rated for UP TO 3,000psi, unless you get hoses special made, and those are out of this world expensive.)

Billy Helton
04-26-2010, 04:19 PM
I agree with ED build it twice a stout as you think it should be. I did say I hade A H frame but I have a C frame (my bad), A six inch cylinder would be better than a five inch, But I havent had any trouble YET. Ed knows alot more about them than I do, thats why I adjust the three way valve and run a gage on the high side to know that Im under twenty five PSi. Here is a pic of my press It might help. Mine is a 14" I beam and I had to brace it also.
http://i873.photobucket.com/albums/ab295/BillyHelton/100_0403.jpg

12345678910
04-26-2010, 05:07 PM
Have a look at Don Fogg's page and don't miss the 5 or 6 other pages with links at the bottom of the page.
http://www.dfoggknives.com/hydralic.htm

There is a booklet he sells there too which runs through specs and designs by an actual engineer.
-the Baston book

A pre made shop press is usually unsuitable because it achieves its high power with a large cylinder at a very slow stroke speed

A forging press is usually recommended to have at least 1 or 2 inches per second stroke speed so you can move metal while it is still hot.

If you start doing calculations you will see that it is easy to get a high tonnage, but at a slow stroke speed because of the volume of fluid required.
This takes a large pump and motor.
You may have to reach some sort of comprise on a slightly smaller 5" cylinder instead of 6".
It starts costing real $ to up your pump volume, motor HP and wiring size above 5 hp

Is 50 tons twice as good as 25 ? probably not as good as a fast 25

The larger size will allow you to run larger dies and keep the same PSI at the die level...but there must be a practical limit..

in the numbers Billy gave he is running 2200 psi is 21.5 tons

Buy the book , look at what others have done and do the calculations with what you can buy locally.
I would tend to stay with 5 or 6 inch cylinder, go larger on the pump volume and keep the pressure down to keep the stroke speed up so you can get more squeezes per heat in.
When the steel is hot, you wont' need huge pressures to move the steel and are better served by gradual reductions to preserve your patterns.
the difference between the pump volume at 5" and at 6" is significant.

Don Fogg's specs
10 hp dual pump hydraulic station pushing
16 gallons a minute at 1500 psi.
5" double acting hydraulic cylinder with an 8" throw.
Works out to 14.7 Tons

Indian George
SUPPLIER PART# DESCRIPTION COMMENTS
NORTHERN 1053-C161 BARNES 2 STAGE PUMP -11GPM
2010-C161 PRINCE STANDARD 4-WAY CONTROL VALVE
4051-C161 7 GALLONS HYDRAULIC OIL TANK MUST CLEAN THE INSIDE WELL
4022-C161 RETURN LINE FILTER
4010-C161 SUCTION STRAINER THIS GOES INTO THE TANK
FITTINGS AND HOSES YOU WILL NEED 3 HI- PRESSURE HOSES AND LOW PRESSURE HOSE FOR THE RETURN.
53606-C161 GLYCERIN FILLED GAUGE 0-3000PSI
SURPLUS CENTER 10-1485 ELECTRIC MOTOR I USE A 3 HP AT 3250 RPMS
09 4954 HYDRAULIC CYLINDER I USE A 4 1/2" BORE X 8" STROKE WITH THE PUMP AND MOTOR SHOULD GENERATE 24 TONS

"If I ever build another one it would be a H press with a minimum 5" cylinder."
__________________


Eric Fleming
WIP with automated stroke timing
http://www.bladeforums.com/forums/showthread.php?t=648250&highlight=press

Material list
http://www.bladeforums.com/forums/attachment.php?attachmentid=137813&d=1247009168

Motor – 7.5 HP
Pump – Single stage 5.2 GPM (Single stage is necessary to get repeatable timing for an automated stroke)
Cylinder – 5” X 8” Stroke

calculations.
http://www.bladeforums.com/forums/attachment.php?attachmentid=133500&d=1243476166


**************


220V motors are practical in these sizes

coyotedown
04-26-2010, 07:23 PM
Thanks for all the input from everyone. I notice most of you are using large horsepower motors. Is there a reason to use a large motor or would a 110v motor putting out 2500 pressure be enough? Maybe if we get enough information and pictures we can make this a show us your presses thread.

Steven Kelly
04-26-2010, 08:16 PM
Thanks for all the input from everyone. I notice most of you are using large horsepower motors. Is there a reason to use a large motor or would a 110v motor putting out 2500 pressure be enough? Maybe if we get enough information and pictures we can make this a show us your presses thread.

I would say that a 5hp motor is about minimum required. I started out with a 5hp 3450rpm and then switched to a 5hp 1725rpm. The quality of the motor also makes a huge difference. An elcheapo air compressor will over heat from the constant cycling. Spend the extra $ and get a good TEFC Leeson or Baldor motor.

I am running a 5" cylinder on my press. But would prefer to have a 6".

Also, as Ed said, A bypass or pressure relief valve is a must for safety reasons. A pin hole leak in a hose at 3000 psi will drill a hole through you...

Billy Helton
04-26-2010, 10:45 PM
I would say that a 5hp motor is about minimum required. I started out with a 5hp 3450rpm and then switched to a 5hp 1725rpm. The quality of the motor also makes a huge difference. An elcheapo air compressor will over heat from the constant cycling. Spend the extra $ and get a good TEFC Leeson or Baldor motor.

I am running a 5" cylinder on my press. But would prefer to have a 6".

Also, as Ed said, A bypass or pressure relief valve is a must for safety reasons. A pin hole leak in a hose at 3000 psi will drill a hole through you...

Thats a sweet looking press steven

12345678910
04-27-2010, 06:42 AM
Thanks for all the input from everyone. I notice most of you are using large horsepower motors. Is there a reason to use a large motor or would a 110v motor putting out 2500 pressure be enough? Maybe if we get enough information and pictures we can make this a show us your presses thread.

"would a 110v motor putting out 2500 pressure be enough?"
Are you looking at premade hydraulic power pack units?
They are no good for forging, as I mentioined earlier, pre-made shop presses may generate enough force, but the ram speeds are too slow.
If they would work well, then everyone would use one and no one would be building presses.
Some people rebuild log splitters, but if you don't already have one to start with, skip that it's cheaper to start with parts.


Horsepower required is part of the calculations on Eric Flemings Excel Spreadsheet
http://www.bladeforums.com/forums/attachment.php?attachmentid=133500&d=1243476166

and I suspect that they are based on the specs in Bastons book
Horsepower =PSI X GPM X Efficiency Rate(100% used) / 1550

Sure you could use less, but then you would have to get your RPM and GPM specs down and then you may not be happy with it.


On Baldor's website for example a 5 hp motor is not available in 110v, it's not practical.
(you may have a 110V air compressor that is listed as 5 or 7 hp or something crazy like that
but those are total BS numbers that they should have stopped using after the lawsuits.)
http://www.wisedan.com/aircomp.html

220v vs 110v
If you go down to a 3 HP motor, you can get a dual voltage motor that could be wired 110 or 220,
but at 110 it would draw 30 amps and need 35 amp breaker and wiring,
it is actually cheaper to go 220v

3450 rpm motor will give you the most pumping volume as pumps are listed as displacement per revolution.

Why are you thinking 110 over 220?

coyotedown
04-27-2010, 02:19 PM
The reason I was initially thinking of 110v is because I found a 110v hydraulic power pack that was portable. I did not realize everyone was using motors around 5hp. I was going to have the power pack be seperate from the press.

coyotedown
04-28-2010, 09:48 AM
I've got another question for you. Do the dies touch each other at the end of the stroke or does it stop just short?

Billy Helton
04-28-2010, 11:00 AM
Mine can touch, I dont think its good to bottom out your cylinder in the up or down position. I may be wrong, I have been there many times. I and most people use stop blocks to set the size of the presses that you want.

coyotedown
04-28-2010, 11:55 AM
How far past your dies would yours go if it didn't touch first? What are stop blocks, how are they used, and what are they made of? Do people put stop blocks on the retraction side of the shaft also, and is it just the coupler that goes around the shaft?

Billy Helton
04-28-2010, 04:29 PM
My stroke will not bottom out on the down stroke. I would in therioe go about 1/2 past were my bottom dye is. A stop block is something to stop the cylinder at a certin height. Say if you want to make A one inch square bar ,use a one inch spacer in between your dies. If you want a 3/8 billet use 3/8 stop block. You can put a collar block on your polished rod if you want for the up stroke.

coyotedown
05-01-2010, 12:13 AM
I know I am going to build an H press. I see them with cylinders on top or on bottom. Do you guys have any opinions of which would be better or worse, or any reason to build it one way as opposed to the other?

EdCaffreyMS
05-01-2010, 06:56 AM
I don't think it's a matter of one being "better" than the other, it's a matter of what an individual gets used to using.

I do think that safety should be a concern when choosing whether to built a top or bottom cylinder version.... IF a person chooses to build a press with the cylinder on the bottom, I think it would be wise to consider that all of the hot scale and other junk, including dropped billets will fall in that direction. If there are exposed hydraulic lines or electrical wiring in that location, you run the risk of dropping hot stuff on them....not good in my opinion! Some keys that I would consider is the placement of the hydraulic lines, the electrical wiring, the motor (especially if your going to use and "open" housing motor), and the fluid tank. None of those items are going to react well to hot scale or steel. Scale that gets sucked into a motor winding means a dead motor at the very least. Hot steel dropped on wiring or hydraulic lines can be a disaster in a split second.

What must be understood when building a forging press is that you have so very many hazards to consider, not only those hazards that come from handling hot steel around things that don't react well to it, but also keep in mind that few people realize the incredible amounts and varieties of forces that are present until they have experienced them.
Considering those "forces" it's imperative that the frame of the press be super strong and heavy. The point of most presses is to be able to forge things into squares, a press frame that flexes will produce diamond shaped cross sections, which once achieved are nearly impossible to fix...and really don't have much use in what we do.

My personal opinion is that a press that has the cylinder mounted on the top, is safer, UNLESS a person designs a bottom cylinder press in such a manner that any exposed components are enclosed or covered. Whichever type you choose to build, keep as much of the lines, electrical, etc. on the opposite side of the main beam from where you work as you can.