Making a hydrolic press

[Manimal Instinct]

Whelp, basically I need a hydrolic press. I've been searching around the internet and racking my brain as to how I could effectively make a functional press for forging while keeping it economicly feasible for myself. Getting scrap to build it out of is np. I can find anything I could possibly need. But I'm a mechanic and we use a hydrolic press for various tasks. Ours is not even remotely an option to me as it's a hand pumped bottle jack in a steel frame. Super slow. On the other hand, we have scissor jacks on our 4 post lifts that are air over hydraulic.

I need links, and or information as to what I need to be looking at achieve the best result. I need a control, preferably something that can act as a foot pedal, but the hand lever is tolerable. The one thing about the air over control is that I need it to bleed off pressure as soon as I release it. That or have a secondary function in the opposite direction to operate the release.

I need suggestions/links on what hydrolic cylinder I should be looking at for the press. I don't want it to be super fast, but relatively, and I honestly don't know how much pressure is necessary, but assume 20 tons is sufficient? Anyway, suggestions are very much welcome.

Lastly, I need to know what would be sufficient to use as a press frame. Like should I be buying a crap ton of 1/2" steel to cut and weld to reinforce for the pressures, or would a regular old shop press frame be sufficient for the task, and I can build on it from there?

 

[rdg]

What about a 20 ton jack that is operated by air? I've seen ones that can either be hand pumped or attached to an air supply.
Bob

 

[3fifty7]

An air over hydraulic jack is so terribly slow it will suck so much heat out of your steel, it’s a sub par option.

 

[Onies]

Lots of variables here, and can be intimidating but if you follow first principals it is fairly easy. You mention 20 tons of force but no cylinder diameter, so for arguments sake, let’s say a 5” cylinder. Area of a 5” cylinder is roughly 19.6 square inches, so using F=PA, 40000lb=Px19.6, so for a 5” cylinder you would need 2040psi. The next question would be horsepower limitations and determining what available flow you could achieve. For example, let’s say 5Hp for your electric motor:
HP=QP/1714, so flow would work out to 5x1714/2040, or 4.2GPM. Electric motor speed will influence this so we would need to know the shaft speed of the motor. How fast would you need to run the cylinder and would the calculated values be enough, to move the 5” cylinder 1” requires 0.085 gallons so with the flow of 4.2GPM, the 5” cylinder would move 49 inches per minute. Is this fast enough? Next would be valve selection. I would say a D03 valve should be able to pass 4.2 GPM with very little difficulty. I would recommend a 3 position tandem centre valve. Primary pressure control can be achieved by a relief valve if you are using a fixed displacement pump. As I said, it can get a little complicated.

 

[Onies]

Lots of variables here, and can be intimidating but if you follow first principals it is fairly easy. You mention 20 tons of force but no cylinder diameter, so for arguments sake, let’s say a 5” cylinder. Area of a 5” cylinder is roughly 19.6 square inches, so using F=PA, 40000lb=Px19.6, so for a 5” cylinder you would need 2040psi. The next question would be horsepower limitations and determining what available flow you could achieve. For example, let’s say 5Hp for your electric motor:
HP=QP/1714, so flow would work out to 5x1714/2040, or 4.2GPM. Electric motor speed will influence this so we would need to know the shaft speed of the motor. How fast would you need to run the cylinder and would the calculated values be enough, to move the 5” cylinder 1” requires 0.085 gallons so with the flow of 4.2GPM, the 5” cylinder would move

 

[weo]

would a regular old shop press frame be sufficient for the task

No. These are NOT built for the stresses involved in forging. I'm sure others will chime in with more detailed answers.

Have you read through the stickies?

I'd suggest using the search engine and spend a bit of time reading some of the prior threads about this topic. A lot of your questions have already been answered.

Bladeforums Custom Search Engine

This is the engine to use to search for info and old threads. https://cse.google.com/cse/publicurl?cx=012217165931761871935:iqyc7cbzhci

bladeforums.com

 

[Ken H>]

Here's a thread with a bit of info on forging press: https://www.bladeforums.com/threads/log-splitter-press-cape-cod.1811541/
Here's a neat link for calculating tonnage: https://www.baumhydraulics.com/images/calculators/cyl_calc.htm

Now, what is your budget? You mentioned you can get most all the metal required for building the frame? That leaves:

$150 for motor (3hp 1 ph, 3600 rpm air compressor type)
$250? for Pump, Control, coupling, etc
$133 for 4" cylinder shipped (good for 16 ton at 2550 psi)
$100 to $200? misc hoses, connectors, etc
$100 for 10 gal oil tank

Call that around $700 to $800 depending on part prices at the time. That does NOT include any metal for frame.

Depending on the metal available you might wish to build a "H" style frame as used by Coal Iron's 12 ton press (actually only 9 ton since it uses a 3" cylinder)

12 Ton Mini-Press

Our 12 ton press is built to provide an economical and compact option for those working in small spaces. Mount to a bench top or stand in either down-acting or up-acting configuration. Running on any 110v 20 amp outlet allows you to take the press anywhere in the shop and even outside with an...

coaliron.com

While the Coal Iron press is "rated" for 12 ton using 2X2X1/4" angle, building with 3" angle will allow 16 ton no problem.

A "C" style does offer some advantages, but also cost more due to amount of steel needed.

Weather you need a 12 ton or 30 ton press depends on what you want, how much money you wish to spend, and how fast you wish to work. The Coal Iron's 9 ton press does an amazing job of making Damascus billets. While that 30 ton press might press 12 sq in at a time nicely (2" wide billet over a 6" wide die), the Coal Iron 9 ton press uses a 2" wide die so is only press 4 sq in. That's 2.25 sq in per ton, while the 30 ton press is 2.5 sq in per ton. (Did I do the math correctly?).

All depends of "on a budget" vs "money is no concern" when shopping.

Have fun designing and building.