Here's a bit of Hydraulic info.

[frijoli]

The pump on the combine was running at 2400rpm at full throttle. I don't have a clue what rpm was used to get the 12gal/min rating.

I rounded up two 4" cylinders today. They look to be in good condition other then the screw on cleves was worn on one and 1" broke off the other. These are cheaper cylinders so not over 2000psi.

Didn't get time to track down the relief valve, but I did get the motor and pump set up with about a 3:1 reduction and built 500lbs before the motor stalled. Not sure of HP but it is small and every thing is in metric. 4kw? So I need to get my brothers cataloge out and get a 5 or 6 hp. Beginning to wonder if this is going to be worth it. I also have tow other pumps. One is a vane pump but I think it is high volume to run motors. The other one I am unsure about other then it says gre-son. No other markings.

I may have to settle with lower tonage. 1.15"/second sounds plenty fast, maybe to fast if you were trying to press a bearing or something but I do have a flow control valve.

Hp is HP no matter how you approach it. a 5 hp motor reduced in RPM still produces 5 HP.

Honestly I think if you buy a Hi/lo pump you'll be way ahead, BUT you need a cylinder capable of higher pressures. Like 3000 PSI. Which you cylinders may be capable of in short peaks of pressure.

Haldex Hydraulic Pump — 13.6 GPM, 2-Stage, Model# 1001506 | Pumps | Northern Tool + Equipment

I've been around this stuff a fair bit and have seen a LOT of people waste a lot of time because they don't grasp the physics behind what's happening.

I'll be happy to help you with the circuit, but I don't believe you're going to get where want to be with just the components you have.

Clay

[Hamstn]

I don't believe you're going to get where want to be with just the components you have.

I was kind of figuring that. I am willing to sacrifice speed or even final tonnage to put something together on the cheap. Maybe just using a 35ton jack for $100 or the one I have would be a better route but I hate bottle jacks. Thought about the air over units but a bit more then I have right now.

Thanks for the link. So a 1800-3600rpm 6hp motor on the pump you linked will run the pump? I also looked at the power units NT listed and they all run in the range of 1.25GPM 2000psi except the one with high low pump.


So where does the air over or hand pumps that run small cylinders get their pressure and such high tonnage ratings? I mean a porto power unit produces 10,000 psi running 110psi of air. My 10ton unit has a cylinder of maybe 2".

What is the pro/con of this one? http://www.northerntool.com/webapp/w...0127_200330127

[frijoli]

I was kind of figuring that. I am willing to sacrifice speed or even final tonnage to put something together on the cheap. Maybe just using a 35ton jack for $100 or the one I have would be a better route but I hate bottle jacks. Thought about the air over units but a bit more then I have right now.

Thanks for the link. So a 1800-3600rpm 6hp motor on the pump you linked will run the pump? I also looked at the power units NT listed and they all run in the range of 1.25GPM 2000psi except the one with high low pump.


So where does the air over or hand pumps that run small cylinders get their pressure and such high tonnage ratings? I mean a porto power unit produces 10,000 psi running 110psi of air. My 10ton unit has a cylinder of maybe 2".

What is the pro/con of this one? http://www.northerntool.com/webapp/w...0127_200330127

As to the pump you listed I don't see anything wrong with it. It looks like a copy of the Haldex design.

As to the porto unit, they trade speed for pressure. Specially designed high pressure cylinders too. They use what's known as intensifiers. They take a big piston driven by air pressure and force a really small piston that translates that force into hydraulic pressure.

See below: The left is the hydraulic side, the right is 100 times the area of left. 100psi times 100 equals 10000psi


This is just an example. The actual sizes are like .375Ø to 2"Ø

[Hamstn]

Ok I have done more research and decided the only way to get a working system is close my eyes and buy a pump. The only place I have looked right now is NT. The only pump that I can find to fit my 1.5hp motor is this one: Haldex High Pressure Hydraulic Gear Pump .097 Cu. In., Model# 1002963 | Pumps | Northern Tool + Equipment

If I have my math right @1800 rpm .75gpm @ 3000 = 1.3hp
Two 4" cylinders is 25 sq" so 7"/minute or .12"/second. A bit slow for applications such as shearing or bending but good control for things like pressing bearings and such. I could upgrade to 3600rmp motor or run belt drive and double that speed if needed.

Better if I can find a smaller hi/low then the one you listed above.

Maybe I will run down to the local shop. I know one guys there and see what they would have.

http://stores.daltonhydraulic.com/-s...ter/Detail.bok this one looks to be the best I found.

[frijoli]

Ok I have done more research and decided the only way to get a working system is close my eyes and buy a pump. The only place I have looked right now is NT. The only pump that I can find to fit my 1.5hp motor is this one: Haldex High Pressure Hydraulic Gear Pump .097 Cu. In., Model# 1002963 | Pumps | Northern Tool + Equipment

If I have my math right @1800 rpm .75gpm @ 3000 = 1.3hp
Two 4" cylinders is 25 sq" so 7"/minute or .12"/second. A bit slow for applications such as shearing or bending but good control for things like pressing bearings and such. I could upgrade to 3600rmp motor or run belt drive and double that speed if needed.

Better if I can find a smaller hi/low then the one you listed above.

Maybe I will run down to the local shop. I know one guys there and see what they would have.

http://stores.daltonhydraulic.com/-s...ter/Detail.bok this one looks to be the best I found.

Your low speed numbers look right, but keep in mind, MOST of the time the pump will be operating at a lower pressure and higher flow. Which means 3.5 GPM during the majority of the cylinder movement.

You can't belt drive these pumps unless they specifically say so. The have no load bearings in the shafting. 99% of pumps are typically direct drive, and that is what I recommend.

I like the the hi-lo 7gpm pump listed running at 3600rpm better with a 3 HP motor, but I think I would try it with the 1.5hp at 1800.

I would check prices on a 5 or 6hp motor and buy this pump, Hydraulic 2-Stage Pump - 11 GPM , IF I thought I might buy a new motor. The high pressure section is identical to the smaller one.

You're heading the right way now!

Clay