Firewood processor help

[jonix]

I don't believe you have any idea of the pressure developed by maxing out the cyl.i told you, i´m no pro

Eve then if you do see some pressure, what is the valve recommended relief setting? yes, i saw 350 bar of pressure on those pressure gauges, but the recomended relief pressure is about 3000 psi

Who developed this idea of the two pumps for a single cyl when there are pumps available. with the displacement you need.this project began with the purchase of all hydraulic circuit to a hydraulic stuff company near by, they have an engineer to do all the calculations, and it was spendt about 6000€ on this..and i agree with, why so many pumps, if you don´t have the power to run it all at the same time..think the engineer messed all up

I am not even sure you can get a valve or cyl that will take that pressure.

The cyl and pump manufacturer, have they supplied parts to other log splitters? think not

How did you start this process of putting the parts together.first by drawing it, second hydraulic circuit, and then steel

Did you know how much tonnage needed to get the job done.well, god question, think 40 tons should be more than enought for eucalyptus

Did you start with the electric motor and that becomes your limiting factor as to the displacement of all the pumps.gas here in portugal is not cheap, and did´t know NOTHING (still about firewood processor oil flow and power about a year ago

Has anybody ever built a log splitter with the capability of 84 tons?i think there are splitters in the market with more than that..but..

Something is wrong with this total process. don´t tell

Just what are your limiting factors. Are you stuck with the parts you have.yes, now i´m stuck with the parts.. I managed the company swapped the F11-005 to a F11-010 and the pump that feeds this motor..inicially, the engineer calculation was a 3 Gal/min pump for the F11-005 (that can work with 14 gal) he choosen, and one more valve for the saw cylinder..he put both on the same circuit..engineers..think that I can not ask the company to change anything else...relational problems already exist..

What is the pressure ratings on your cyl, and valves. don´t know...i will try to get this

What is the name and model number of the log splitter valve or is it even a log splitter valve.i think it is not a splitter valve, wonder if the engineer knows how firewood is made...i can get these number tomorrow..

Your F-11 saw needs about 15 GPM minimum to run and if it can develop 6000 psi, you need about 29 HP just to run the saw.

If the log splitter valve is limited to about 3000 psi, due to the relief valve, then you only need about 15 HP

The saw will run at any GPM, but the speed of the saw motor is relative to the GPM.

You can increase the speed of the saw, but the torque will decrease.yes, think this part will be solved with the F11-010..




Apparently, you are not using a standard log splitting valve with auto return.

I see all solenoid valves, but where is the relief valve? do you Know the tecnichal word for "relief valve" in Portuguese?

Early on you said you did not know what that was, but it is of great importance as it will protect the pump from excessive pressure.

Every hyd system should have a relief valve, and each circuit should have one. .

Your two p mps at 24.2 GPM and 3000 psi, would require about 47HP.

I think someone messed up on total HP required.

Your cyl and valves have a psi rating, what is it?

The cyl will take what ever GPM is fed into it and develop the pressure based on the load.

Motor stalling will be based on the total load on the pump, which is driven by the electric motor.

thank you J.J, but as you see, there are knowledge limitions here, and post almost a year, when we did some primary testing, the result was this..

 

[ptsg]

Relief valve means "Válvula de pressão", I'm from Portugal too

I think that they did a two stage pump with too separate pumps and a separate valve, instead of a regular 2 stage pump like it's usually in log splitters.

 

[J_J]

Is the GPM correct or the cu in displacement correct.

What you could do is to run one function at a time, to have enough HP to get things done.

The GPM of a pump is rated at max rpm, and if you run it at half speed, the GPM will be halved.

If your cyl is 6 in bore and 3.5 rod, and pump pressure was 3000 psi, your cyl could develop about 84,832 lbs, or 42 ton. Retract tonage will be less.

Your speed will be determined by the GPM into the cyl.

You could also build a lockout function so only one valve has power at a time, or whatever will allow you to maintain HP at all times. .

 

[jonix]

Relief valve means "Válvula de pressão", I'm from Portugal too

I think that they did a two stage pump with too separate pumps and a separate valve, instead of a regular 2 stage pump like it's usually in log splitters.

yes, i know..the relief valve question was not really for J.J

And what is the diference between a regular 2 stage pump, and 2 separate pumps?

 

[jonix]

So J.J, this new one cylinder with a 6,3'' inside camera, and 7,87'' outside with the same 3,5'' rod will develop how much tonnes of power? how do you do the math?

I have a question, maybe you can answer it: if my two pumps at 24.2 GPM and 3000 psi, would require about 47HP, and i only have 25Hp, what is happening in the hyd system?..guessing, since i saw it working with this setup: with 25HP i can pump 25 GPM (rounding), but only at half of pressure, since i have half of power..or i can only pump half of GPM and the same pressure?..can you post the formulas for this calculations, so i could understand it ...i think this part of the math is important too..guessing..

 

[J_J]

Go here. Surplus Center

Select technicall help.

On left side, select hydraulic calculators.

Hydraulics
Calculators
Cylinder Force & Speed
Gear Pump Replacement
Pump Disp., HP, GPM & RPM
Motor Speed, Torque & HP
Cylinder Definitions
Cylinder Ends
Hose Sizing
Pumps & Motors

Select pump Disp

Plug in some numbers and there you go.

Whatever you put together, if the hyd are not working under a load, you do not need much HP.

You will have max flow based on the pumps max rpm.

As soon as the hyd sees a load, pressure develops.

The HP required to support that load, pressure, etv, will be met and things work OK to a point.

If you add more load than the system has HP, you are at your max, and after that, you may stall the system.

Did that engineer do all the math for you or is that your doings, and did you just ordered the parts based on his recommendation.

I say again, you can use some of what you have, but can not use all pumps to full advantage at the same time.

What you try to do in a hyd system is to design for min operation, and then add some extra for true operation. Design for maximum potential. .

If you run out of HP, the system will slow down, quit or burn up the motor.

It would be analogous to you pushing a bolder on level ground and then you try and push same bolder up a hill. Need more power.

Had you put your design on TBN before, someone could have saved you a lot of headaches.

However one has to know the true details, such as HP, cu in, size, etc.

 

[jonix]

very nice this surplus center..thanks!

I think i understand now..as the system develops pressure, at the design flow rate (25GPM), it will be needed much more HP..since i only have 25HP, the electric motor wants to shut down.. i should have, for example, a 20GPM pump with low pressure, and a switch for a 5GPM pump rated with high pressure, to do get the job done..think this is the 2 stage logsplitter pump that ptsg talk about..:thumbsup:

..all the math was done by the engineer..we only said the purpose of each machine moving part, and if it will be moved by a hyd motor or a cylinder..

..well..i think i solve my problem by getting one of those 2 stage pumps..but they already doing a bigger cylinder for the splitting part..at the shop there is not much patience to wait and do things well..

 

[oldnslo]

jonix,
here are some formula based on the metric system.

For reference:
The saw pump of 34 lpm @ 150 Bar requires 10 kW power at 85% efficient

Splitter pumps:
50 lpm @ 250 Bar requires 24.5 kW power at 85% efficient (I used 250 bar since a lot of gear pumps are rated to 250 Bar)
this does not take into consideration any other loads on the motor of which there will be.

 

[J_J]

This is the largest 2 stage pump that Surplus sells, at 28 GPM. Min of 16 HP engine

28 GPM DYNAMIC 2-STAGE PUMP

You need 13.6 HP to pump 7 GPM at 3000 psi
------------------------------28 GPM at 800 psi

How are you going to power a two stage pump with pumps piggybacked to each other?

You can adjust the crossover psi between 400 and 900 psi/

 

[ptsg]

So you are saying that with two independent pumps, one with high GPM and low pressure and other with low GPM and high pressure, with the proper valve to swap between pumps, can´t do the same as a 2 stage pump? Because it is probably what jonix has in his processor.

The problem that jonix is experiencing must be the relief valves and unloading pressure not set right, it probably cause the system to produce excessive pressure when it shouldn't.

For what I can see, this processor is made to work automatic, that's why they use solenoid valves and not a log splitter valve.