hydraulic pump question for a press

[Mr Fixit]

Hi Group,

I have the 10Ton HF porta power and want to use the pump for a hydraulic floor model shop press. Can I take the pump up to 20Ton if I find the correct size cylinder? I'm looking for suggestions on the press cylinder that would work. I have built the steel frame and am in the process of finishing the table, so it's not done yet but I'm getting close. The hydraulics are still not figured out yet.
I did consider the bottle jack idea, but I'm hoping to have the type with the trolley for the cylinder to do off center presses.

I look forward to all comments and suggestions. Oh, and I'm not going to go buy one, it's about the journey as much as it is the end result.

TX
Mr fixit for the family
Chris

[I make chips]

The pump has no idea of the tonnage it's producing. It only produces x flow at x psi. If you increase the diameter of the cylinder it's powering it'll naturally provide more pushing pressure. As the diameter of the powered cylinder increases the speed of it decreases.

If you want to calculate the press pressure, https://www.sensorsone.com/piston-cy...ce-calculator/

[true temper]

You will need a cylinder with twice the square inch of piston surface to get 20 tons. Also needs to be rated at 10,000 psi, but it will work if your pump has enough oil capacity.

[ed_h]

I did one similar to what You describe. The 3 inch diameter cylinder gives a calculated max force of a little over 20 tons. Pics:

http://bullfire.net/Press/WP_HydPress.html

[metalmagpie]

You may wonder (I sure did!) what exactly makes one cylinder be rated for 2500 psi and another for 5000 or 10000. I found out recently. I had an old cylinder which I'd bought to use in a hydraulic press thinking it had a 5" piston. It turned out to have issues. I learned how to tear it down, machine a new rod, buy new packing and reassemble it. It was when I was buying the seals for the piston that I realized the catalog said those seals were rated for 2500 psi. Ah HAH! I'd wondered if they did xrayed welds or something to make the thing stronger. Nope, it's just the soft stuff. The rubber on the piston and on the gland around the rod are what determine the maximum psi.

You are going to be hard pressed to find any cylinders not made for a portapower that are rated for 10000 psi.

It's laughably easy to come up with a 20 ton hydraulic press. Buy it at Harbor Freight. Now, if you want a fifty ton press ...

metalmagpie

[754]

You can run a bottle jack on a trolley as well.

[Mr Fixit]

Hi ed_h,

That is the one that I have copied, from your post. Mine is a bit different in size but the basic design I'm using is from yours. Thanks.

I make chips, I appreciate the calculator too.

I'm on the hunt for a cylinder now with the information gained here.

TX
Mr fixit for the family
Chris

[Doozer]

Dude, you are gunna pump it a million times to get 1" of travel.
Hope your arm holds out.

-Doozer

[wierdscience]

Cylinders are easy, just do a search on ebay or amazon for 20 ton hydraulic ram.

Like Doozer mentioned, pumping the hand pump will get old quick. I got a couple of these from HF-

https://www.harborfreight.com/10000-...ump-98318.html

Works with the 20% off coupon too.

[ed_h]

Check these guys out for cylinders:

https://www.surpluscenter.com/

Ed

[wdtom44]

Pumping a hand pump may get old but it gives you a bit of feel for what you are doing. With a powered pump you don't have the slow feel for what is going on. Even with a gauge to watch it may be hard to control with power.

[dian]

but you get stick slip with the hand pump.

[Mr Fixit]

HI guys,

Great feedback ! Doozer I do not have the arm of a gorilla so I need to heed what you say. Wierdscience, do you use the HF pump for this application and does it give you the control that wdtom44 speaks about, because the one at work is a hand pump not modified, but a manufactured unit and I do not pump it all day and I do like the feel of when it is getting up to pressure for control.
What is stick slip Dian?

TX
Mr fixit for the family
Chris

[CPeter]

They do have 2 stage manual pumps. Best of both worlds.
"Enter the PowerX P37 “two-stage” 10,000 psi (700 bar) hand pump. Two stage hydraulic hand pumps give the operator higher flow rates up until the cylinder or ram starts to do work. In the case of the PowerX P37 hand pump, the first stage has a flow of 0.79 inches3 of oil per stroke (almost 4 times more than the P43) before making contact with the work load where the pressure builds. Once the ram makes contact with the load, and the pressure inside the system raises above 200 psi, the second stage kicks in at 0.17 in3 of oil volume. This two-stage pump allows the operator to do less work (or hand pumping) before coming into contact with the load. Your operators will thank you!

[reggie_obe]

No auctions in your area of Oregon where you might win an electric hydraulic pump? Greenlee, Enerpac, etc.
How about lot 131
https://www.bidspotter.com/en-us/auc...id-pahl-i10041