Firewood processor help

[J_J]

Did you ever go into Surplus hyd and use the calculators.

Surplus Center.

 

[jonix]

At this point, i already have an excel spreadsheet I have been working with for about last 2 weeks.
I was able to confirm my spreadsheet results with surpluscenter (and others), and i have math to convert for several units of measurements (most metric and american). IF you want, i can give it to you..it takes in consideration some variables that surplus center doesn't, and it serves my propose better..i think it is a nice tool that can bee upgrade (or any possible mistake correct) by any of us..

I make this spreadsheet based on math formulas mostly for HP requiered, oil flows and pressures, advancing and retracting times for cylinders, tonnage, torque and HP for hydraulic motors, torque and HP for sprocket and chain, math for pulleys ratios, chainspeed, rpm's, motors displacements, etc..

So, yes, i already quit going online at surplus center do to this basic math..

Now..surplus center math (and world math) for torque is: MOTOR DISPLACEMENT x SYSTEM PRESSURE (x mechanical efficiency)

Torque at a hydraulic motor is not afected by rpm, that is given by oil flow at pump. This even't be part of the equation in surpluscenter, or other place else!

so, am I missing something?..if do, please tell me..

Only pulleys or belt ratios to change rpms can afect torque..even sprocket syze afect torque ..type of wood and chain afect torque efficiency..FLOW doesnｴt afect TORQUE at this basic level of calculations and math..

 

[jonix]

Well, think this topic needs a "restart", because things are quite messed..you are talking about to much more problems that we really have, i think..please make me one question at the time, and i will answer whatever you want to know, if i can..you keep saying enginner that, HP required this, you must change mostly everything in your circuit because that is all wrong, etc..doesn´t you see the videos of the machine splitting with the HP i have? and it was not working? was it so bad?

Did the engineer make mistakes? YES he did..he inicially even put a 3,5 GPM pump to feed the F11-005 saw motor..so..

What else mistakes the engineer did? no big mistake else, i think, unless the cylinder syze calculations for eucalyptus splitting, for the pressure limits that he configured itself.

He put a "2 stage pump" for splitter with a 2,5:1 flow ratio..think this ratio configuration should be better..maybe 3:1 or even 4:1..it would slow down the splitter in high pressure stage, but it will have more power..and dry eucalyptus, you know...
well, now think this part will work just fine: 30 GPM (combined by the twin pumps) in low pressure mode, and 12,5 GPM in high pressure (3000 PSI), giving almost 40 ton of power, and 24 HP required.

So..what's wrong "with you"? ..sorry, "with my circuit"?

 

[muddstopper]

man..you are messing all it up..

The pump flows we have being talking are rated for 1500 rpm..my electric motor have 1470 rpm..

and JJ, are you telling me that the mathematical formula for TORQUE is WRONG..is that it..?

..later iｴm going to post the hydraulics again..to much things going on at the same time..

Mudstopper, YES you are right!! the thing is I have to put this machine working ..I have no firewood drying..as soon as i have the time, i will put some oil flow in the F11-010..maybe I will try to put my twin pumps doing it..i donｴt know if that is possible, but i am going to ckeck it out..

And guys, yesterday we were testing all moving parts manually, i was hable to mesure times and discovered my "twin Pumps" for splitter work exactly like your 28 GPM 2 stage pumps..mine works like this: 30 GPM at low pressure (I can set the relief up to pumps limit pressure, but it will work at 1000 PSI or so) and 12,5 GPM at high pressure (my limit is 4000 PSI for pump ratings, but only have 25HP, have to work with max 3000 PSI) (I Know 2 stage pump usually work with a 4:1 flow ratio, well, mine have 2,5:1 ratio)
I almost have 40 Tonnes of splitting force, i think this part is no bad..the extend and rectract times are not to bad too..

If I am doing the math right, if you put 30gpm (using the low pressure pump of your 2 stage setup), @1000psi, to your .62cuin motor, it should turn 11117rpms. Doing more math your torque is going to be around 8.25ftlbs and give you 17.6 hp. I dont know if a f11 motor is rated for 11000 rpms, might be, you will have to look that up. With the sprocket direct drive to you f11 motor, you should achieve chain speed of almost 9000ftmin. I am pretty sure you should be able to isolate the low pressure pump from your splitting circuit, you may have to tee in before your splitting circuit to make it work. The trick is going to be keeping the high pressure pump from kicking in and back feeding into your saw circuit. I dont know how your solenoid valves are hooked up. If the solenoid valves for your saw circuit are separate from the splitting circuit, it might just be a matter of using a solenoid manifold with power beyond capabilities, which you might already have. In that case, you could plumb the high flow, low pressure pump to the saw manifold and the let PB carry the oil over to you splitting circuit. Of course doing it this way would mean that if you are sawing and splitting at the same time, you saw might speedup and slow down, or the splitting cyl might speedup and slow down as you activate more than one function at a time.

As for the torque formulas, I havent done the math, but it appears too me that you are figuring the torque values before you introduce the 2:1 pulley ratio to your saw. If that is the case, even though the math might be right, the pulley ratio will reduce the amount of torque and hp to your saw sprocket. Think of it like a lever, if you have a lever 2 ft long to move a rock and you shorthen the lever to 1ft, which lever will it be easier to move the rock with. Going to a 2:1 pully ratio is just like cutting the lever in half. You have the same weight on one end of the lever and the same power on the other end, but now the rock is twice as hard to move.

Edit, I may have read your last post wrong, is that 30gpm with both pumps, or 30gpm with just one pump

 

[jonix]

30 GPM with both twin pumps (pump 1 is 17,5 GMP and pump 2 is 12,5 GPM)..pump 1 is rated for a max of 3000 PSI and pump 2 is rated for limit of 4000 PSI)..both pumps have pressure reliefs, that i can manipulate as i want, with my HP source limitations of course..those two twin pumps are working together in a separate circuit with one solenoide, i think..

My saw is workink at another circuit with it's own pump, that as a solenoid and pressure relief too..

All the other functions are at my 3rd circuit with another pump, and 6 or 7 solenoids i think..

 

[J_J]

Either you are not understanding or don't want to, but your numbers do not add up.

Your motor and pump can not make 30 GPM at 3000 psi. That volume and pressure would require about 58.3 HP.

If you used the 4000 psi number to compute HP, it would take about 77.8 HP.

To get 30 GPM at 1470 motor rpm, you need a pump with a displacement of 4.71 cu in. You could spread the displacement across multiple pumps, but the rpm will be the same.

You still need 58 HP or 77 HP depending on pressure.

If you want 30 GPM using your electric motor, then you have to limit the pressure to 1300 psi using 25 HP.

You should also know that any pressure developed is dictated by the load, and the HP requirements will vary through the psi range.

Go to the calculators page on Surplus and plug in the numbers and you might see what we are trying to tell you.

Maybe I should quit trying to help and let you make all the mistakes you want to.

 

[muddstopper]

JJ, I think he is saying he is only making 30gpm @ 1000psi, which is the high flow, low pressure of his twin pump setup. He can only make 3000psi @12. 5 gpm, when his pumps kick into low flow, high pressure mode. This is marginal, but he is also using a electric motor and not a gas or diesel, so its within possibility. I think what he needs to do is to figure out a way to run both pumps thru his saw, staying at low pressure and not kicking into high pressure low flow, yet still have the high pressure, low flow available to run his splitter. Of course he wouldnt be able to run both circuits at the same time, but if he can figure to how to route his hydraulics, he would have a kickass saw and a pretty good splitter. I don think he is going to be able to get the automatic/ run everything at one time part where he wants it without going to a bigger motor size.

 

[J_J]

His pump chart in post #1, has a total flow of 37.5 GPM.

He doesn't have the correct data to figure anything.

I have yet to see the displacement of each pump and the max pressure rating.

I see no purpose of running two pumps into one flow path and monkey with the relief pressures and check valve setups.

Those pumps are going to be pumping out volume, and the load will dictate the pressure.

Again, to achieve 30 GPM, he needs for the two pumps to have a displacement of 4.71 cu in, and to split wood at 3000 psi, he needs 58 HP which he ain't got.

His 25 HP motor can power a 12.85 GPM pump at a max pressure of 3000 psi. There should not be a low and high anything. So, if he sets the two splitter pumps relief pressure to 3000 psi, and check valves on both pumps, then the motor should not stall at max pressure.

 

[ptsg]

How can he not be able to run with the current setup, if he have already run it? He has a video showing it. By automatic, I don't think that he will run all functions at the same time. It will just run one function at a time, so the setup he have right now, it's good to go.

 

[J_J]

I just don't believe he can pump 30 GPM at 3000 psi.

Yes, he can split something, but how much pressure was developed.

I can also lift the arms on my loader at about 400 psi or less with no load all day.

Just about any amount of hyd can do some work, but to what extent.

Just for fun, throw a log in crossways, and see if the load can cause the cyl to build up relief pressure and see how the electric motor reacts.

Show us a video with pressure gauge and the sound of the electric motor.

If you have an amp meter, put it on the motor to see full draw.

I want to see the 3000 relief psi on the gauge.

If I see 3000 psi on the gauge and the motor not straining, then I will concede.

But then, I would like to see correct data on all pumps.

Can you show me flow in GPM's using a hyd flow meter , which will show GPM's.

Just saying the capability, dose not make it so.