Thread: Largeish Hydraulic Press Build

Originally Posted by roverrescue

Dave,
The flow control valve (spool valve) I have sourced has an adjustable pressure relief returning to tank. I havent actually got a pressure gauge in the plan yet so hoping the "pre-set" on the valve is closeish to safe otherwise I guess things will go big-badda-boom!

Steve

which breed of spool valve, just a standard gatey type job or one with rolling ports that give you flow control?

if you can feather the control on the hydraulic side you dont need the additional flow control valve to limit the flow rate out of the pump (I was assuming you were going for the very basic on/off controlled by starting/stoping the pump or solenoid control with a manual relief valve)

Website has changed a little in the three million turns of the hourglass since I started this thread.
But the gear pump is something like this one:
P2A0D6C1U
and the valve is something like this one:
NEW VALVE SINGLE SPOOL 90 LPM 1/2 BSP PORTS GM10/1/YSD-X

Now the 5 horsey motor I have is gonna spin at 2800rpm which I know with a 6cc pump will likely "overrate" the system a shade but my good mate always said that a tinny is rated at about half its actual best HP rating....

I like your system Rick of using a clamp meter to maximise the pressure to the supplied current to the motor... deadheading the cylinder though scares me a little - I think I will need to hide behind two empty beer cartons before doing that test!!!! If Noel hears a bang and they guys in Brisbane hear a muffled thud on Sunday afternoon yall know that my madness has overcome me!

S

Oh and Dave Dave Dave Dave Dave Dave Dave,
" (I was assuming you were going for the very basic on/off controlled by starting/stoping the pump or solenoid control with a manual relief valve)"

Surely my comment in post #7
"Why upgrade unless you go large?"
Should have been your tip off that this was going to be as NON basic and NON manual as possible. I want the lights to dim, the hounds to howl and the metal to groan as this baby puts her back into it... This will be a big boys press that will either kill me or quite possibly kill me

S

By my rough guesstimations, a 6cc pump will give you about 4.4gpm when run at 2800rpm...which will take about 9.2hp to drive at 3000psi.....or 5hp to drive at 1650psi.


Pressure gives you the effort...flow the speed.....a smaller pump will give you greater effort (at reduced speed) for a given HP input..


I would probably crank the relief back a turn or so before initial start up, guessing you will pop a fuse when cylinder is fully extended/retracted if you don't.

Thanks Rick for the numbers,
will see what happens - I dont think one can buy a 10 horsey motor in single phase so might have to make some modifications on the fly!
If this jigger only pulls 1650psi that makes 20,000lb on a 4" ish cylinder which is likely sub-optimal

Perhaps there is some dumb luck in ending up under powered to start with!

When it all boilds down to it - the alleged 20T made in chingaling press I have been using for the last few years inspires my little left toe with as much confidence of safety as an angry mud crab

There is Nooooooooooooooooooooooooo way I would stack 10 commodores on those press plates of that press!!! So perhaps this thing running a 5 horsey motor will do hat i need it to do!

The best suggestion I have had during the build is to use the old 40hp evinrude slowly rotting on the motor stand in the corner to turn a gear pump... stick it way out the back some place and run long hydraulic lines!

S

if you can swap the motor for a 1400rpm one, you will be on the money...or belt drive the pump with a 2:1 reduction. Those pumps don't have a bearing on the input, so this would require some sort of outrigger bearing or dummy shaft arrangement tho......or look for a 6" cylinder......


9T is probably a tad less than optimal, but depends on what your doing with it I guess.....tho I have stalled a 200T tyre press...trying to get some rather large (and stuck) solid forklift tyres off rims...9" grinder and LOTS of tyre smoke!

Reckon I will just try it and see if either:
a/ I let the majic smoke out of the motor
b/ let 20L of hydraulic fluid escape an orifice at high velocity
c/ I cant squeeze a bannana out of its skin

Depending on alswer I will change something

I have heard elsewhere that solid fork lift tyres can be a shade stubborn.

S

Originally Posted by roverrescue

Oh and Dave Dave Dave Dave Dave Dave Dave,
" (I was assuming you were going for the very basic on/off controlled by starting/stoping the pump or solenoid control with a manual relief valve)"

Surely my comment in post #7
"Why upgrade unless you go large?"
Should have been your tip off that this was going to be as NON basic and NON manual as possible. I want the lights to dim, the hounds to howl and the metal to groan as this baby puts her back into it... This will be a big boys press that will either kill me or quite possibly kill me

S

oh well in that case, want to borrow one of the hyd rigs I work with

9000PSI at upto 38GPM driven by 275 HP of angry diesel?

just cause you go large doesnt mean you wont get just the simple stuff....

do you want to know how to make it really complicated?

mulitple pumps running with shuttle manifolds that run parrallel when under low load and then turn the pumps into series so the supercharge each other.. a very quick way of getting ass loads of pressure (assuming the pump casings hold up)