hydraulic pump

[welderboy14]

i am building a towable backhoe and was woundering if anyone know what one

of this pumps would work Gear | Pumps | Hydraulics | Princess Auto there is
4 2'' x18'' strock tie rod cylinders rated at 2500psi

thanks very much for any replys

welderboy14

 

[dfkrug]

Many of those pumps will work, WELDER, but which one you get
depends on what you are going to turn it with.

For 2" cyls, 3GPM is plenty of flow. One stage is enough. What
pressure you use depends on how strong the design is. Pump displacement
depends on how fast your engine will turn the pump to get the flow rate
you want.

My CADDigger 728 had 3" cyls, and I limited my pressure to 1500psi. I
still broke some welds. I prefer engines that don't have to run at 3600RPM
(I tried 2 approaches).

Are you going to use tested plans?

 

[J_J]

I think you need to educate your self about hydraulics in the light of, what do I have and want to use. If you are starting from the cylinder, You want to know what pressure it will operate, speed of the cylinder, GPM, extend force and retract force. What size pump to use with what size engine HP. The more GPM available, the faster things will work, but will require a larger engine. 2 stage pumps are not normally used on something like a backhoe. Will you be using joystick valves? Thickness of the metal, length of the arms, bucket size, etc.

 

[PILOON]

I have an old 'Cricket' towable unit.
It uses a 5 HP 4 stroke that drives 2" cylinders.
While not exactly the fastest in the west, it does an admirable job.
Have 'excavated' 45 gal drum sized rocks that merely protruded the surface, can't lift them but could tumble them out of the way.

Have used many mini tracked excavators of different sizes and my towable is every bit as strong at the stick, just slower at moving about and limited to about 180 deg swing so positioning is where it lacks.

For straight trenching in moderately rocky soil down to 4 ft debth the towable is just fine even with its 5 hp engine.