Not tractor related, but still hydraulic

[handirifle]

I have an ongoing bullet design I am working on and may end up needing to build a hyd press for it. My question is this, if I want to build a hyd press of say 20 tons, what would I need to get er done?

I have an electric motor, I can't remember, I think it's a 1hp but not 100% sure. So far I can think of a coupler, the pump (no idea how to size it) and a control valve, and some sort of cylinder.

I know places like Harbor Freight sell manual pump models for a couple hundred $$$, but I think I would prefer an electric pump.

Suggestions, links to kits or previous builds like this? All appreciated.

[TRR]

The area of the piston and the psi of the hydraulic fluid will determine the 20 ton force. The rest of the numbers (size of the pump in gpm at pressure) will determine the cycle time.

[ch47dpilot]

Look here: Surplus Center - Tech Help on Surplus Center it will help you figure out what sizes you need.

[LD1]

To get 20T you either need a 4" cylinder and feed it 3200psi from the pump, or a 4.5" cylinder and give it 2500psi.

Assuming the 4.5/2500psi route, you will only be able to push about a 0.58 GPM pump. That is only going to give you a 0.1" per second cylinder speed. That is pretty SLOOOOOOW. 10 seconds to move 1"

Its all just numbers, and the formulas are out there. But you are talking a pretty serious cost.

Assuming you have to build the H frame anyway, to go to an electric setup you need the additional:
Pump
Coupling
Motor
Valve
Hoses
Cylinder
Resivoir
Filter setup

If it were me, and since you already mentioned HF, why not get an air-over-hydraulic cylinder?

Like this: 20 Ton Air / Hydraulic Jack

[J_J]

Do you mean like for pressing the bullet in the shell casing?

A 4.5 in cyl, and a 2 in shaft, using 2600 will produce a force of 41,351 lbs or 20.675 ton

Maybe something like this.

http://www.surpluscenter.com/item.as...name=hydraulic

The pressure developed will be determined by the resistance/load on the cyl.

[handirifle]

No, I am referring to production (manufacture) of the bullet itself. As far as the air over hydraulic jack, do those only use the air to move the cylinders till they hit a load, then you have to pump them by hand anyway, correct?

I haven't looked at the provided links, yet, but since the press would only be pushing at the base of the bullet, which would be a diameter of only .375", that would make the press pushing on a little over .11 sg in. Soooo with that in mind, would not say, a 2 ton (per sq in) press actually be pressing 10 times that in the small area?

Does it work like that?

I'm talking a press that would form the bullet jacket or the bullet itself (copper)

[SPYDERLK]

No, I am referring to production (manufacture) of the bullet itself. As far as the air over hydraulic jack, do those only use the air to move the cylinders till they hit a load, then you have to pump them by hand anyway, correct?

I haven't looked at the provided links, yet, but since the press would only be pushing at the base of the bullet, which would be a diameter of only .375", that would make the press pushing on a little over .11 sg in. Soooo with that in mind, would not say, a 2 ton (per sq in) press actually be pressing 10 times that in the small area?

Does it work like that?

I'm talking a press that would form the bullet jacket or the bullet itself (copper)

You are mixing pressure with force. A press supplies force. Whether the item pushed against is small or large is immaterial to the press. It will supply the same force -- but pressure is force divided by area. So the smaller the piece the more pressure. You need a force adequate to form a bullet. Is 20 tons necessary? How much distance travelled while pushing? How fast do you want to make repeat cycles [bullets per time].
larry

[handirifle]

20 tons is probably not necessary, it was kinda a number I threw out there. The travel distance while under high pressure is about an inch, maybe two at the extreme. Free travel could be 3 to 4 inches, so a 6" stroke would be more than enough.

This page at the Corbin web site will explain more Corbin Hydro-Press(TM)

I just cannot afford the ready made machine.

[J_J]

handirifle,

The link you reference talked about two stage pump, probably for fast operation with no pressure on the cyl rod and then high pressure when swaging/compression.

Do you need manual valve or solenoid valve. You could make it automatic by using limit switches,

You need a reservoir equal to the pumps GPM,

You need a relief valve.

The hyd pump only develops volume but is capable of a certain pressure. So any small DA cyl would probably work. The more resistance the more pressure, up to the cyl and pumps maximum capacity.

3 in bore
1.5 in rod
stroke= in inches
pressure 3000 psi
=21,206 or 10.6 ton

Two stage pump, smallest one Surplus hyd carries. .

Surplus Center - 7 GPM 2 STAGE HYD PUMP S20702-5181

If you want faster, find the pump with the more GPM flow. Keep in mind the HP required to power a pump at a certain pressure.

pump @ 1.8 GPM at 3000 psi = 4 HP

Have you seen those machines in operation, and if so, what was the working pressure.

[LD1]

No, I am referring to production (manufacture) of the bullet itself. As far as the air over hydraulic jack, do those only use the air to move the cylinders till they hit a load, then you have to pump them by hand anyway, correct?

I cant say for sure on the one I linked, But most that I have seen do not need to be hand pumped. The air motor moves the fluid. But most have the hand pump because you can use that if you want a better feel.