A Few Quick Questions

[BlueShibaura]

I believe Santa is bringing a CountyLine/Speeco log splitter to add to my arsenal of implements. I intend to initially try it with the hydraulics of my trusty little NH TC30. The 7.1 GPM pump will not set the woods on fire, but I am prepared to add a PTO pump and tank if necessary. The TC30 has been coupled with a Woods 1008 Loader since day one. The loader valve is a Husco 9210-812 B. Nice, but it only has a roughly 2000 PSI relief valve. The power beyond port is plumbed back to a block where the main supply and return are also plugged into the tractor via quick connects. I previously installed the factory NH piggy back single spool valve for the rear remote. It has been great for the top link.

1 - I am thinking the current power beyond line is simply dumping oil back into the tank. If this is accurate, I intend to tap into the power beyond port at the loader valve and then dump it into the quick connect just before it goes back into the 3 hose "block" I mentioned above.

2 - The simplest method to set up on my TC30 would likely be to bungee the remote lever in one direction and plug into the rear remote quick connects currently being used for the top link. Does this actually create additional wear to your system? If so, would periodically swapping feed/return hoses and bungeeing in the other direction help dissipate wear at all? If the possibility of accelerated wear is present, I will buy longer hoses to reach up to my loader valve as previously described above.

3 - All four cylinders on my 1008 loader are puny @ 1-3/4" with 1-1/8" pistons, but are very fast and have proven plenty robust for this small machine. 5/8" [1-3/4"-1-1/8"] x 2 cylinders = 1-1/4". If the log splitter has a 4"cylinder, with 2" piston, the net difference is 2". Correct me if I am wrong, but I don't believe cylinder length affects the movement speed. Comparing the dimensional numbers, is it safe to say that the single 4" cylinder will only be 62.5% (1.25/2) as fast as two 1-3/4" cylinders operating simultaneously. If that is the case, I think I can live with it. Does this correlation apply, or not? It just dawned on me to check the dimensions of my top link. If my math works, that should be a second indication of what I can expect.

 

[J_J]

Keep all the hoses as large as possible.

Use a QD one size larger than the hose size,

A larger cyl will be slower on the same pump flow.

Cyl length is most definitely affected, because the cyl internal volume is increased. Instead of a qt of fluid in a certain amount of time, the larger cyl might take about a gal to fill, and therefore more time.

If your pump will pump a QT in 10 sec, how long will it take to pump a GAL of fluid. 40 sec.

 

[BlueShibaura]

Thank you, kind sir. I did notice the hose on the power beyond being larger diameter than the others. The reason I noticed was because I thought the fitting that screws into the valve seemed small. I will investigate further. At least that will be the hose I replace to reach the rear if I tap into the power beyond port. All my hypothetical calculations of two smaller cyliders simultaneously moving comparably in speed to a single larger cylinder are silly anyway. It will be what it will be. Nice to have a plan B for a PTO pump for sure.

If I may...

What is the difference between Maximum Operating Pressure and Maximum Tank Pressure? My loader valve is rated at 2080 and 3000 psi, respectively. Which is used for tonnage calculations?

What about the shortcut of strapping the rear remote valve lever in one position to feed the splitter valve... Should I avoid the idea of that technique?

Are the pumps in these Shibaura machines single or two stage?

I have read just enough to learn a few questions to ask, and that's about it so far. Santa is patiently awaiting my order. Otherwise, I would have kept searching and reading before asking such simple and repetetive questions. I do apologize for jumping in with an impersonal technical probing of a first thread. Thanks again.

 

[J_J]

Maximum operating pressure is the max pressure the pump should be exposed to. A relief valve is designed to protect the pump.

You can lock or tie back that valve on the remote when you can use the lever to supply flow to a hyd attachment, but why go through the remote when you can just plug in your splitter into a QD at the back.

The tractor pump is probably a single stage gear pump.

Your relief setting and the size of the cyl will determine the power. The GPM will determine the speed of operation.

You basically match hose size to port size. It doesn't hurt to go larger if you have the space, but larger hose and fitting are more expensive.

 

[LD1]

3 - All four cylinders on my 1008 loader are puny @ 1-3/4" with 1-1/8" pistons, but are very fast and have proven plenty robust for this small machine. 5/8" [1-3/4"-1-1/8"] x 2 cylinders = 1-1/4". If the log splitter has a 4"cylinder, with 2" piston, the net difference is 2". Correct me if I am wrong, but I don't believe cylinder length affects the movement speed. Comparing the dimensional numbers, is it safe to say that the single 4" cylinder will only be 62.5% (1.25/2) as fast as two 1-3/4" cylinders operating simultaneously. If that is the case, I think I can live with it. Does this correlation apply, or not? It just dawned on me to check the dimensions of my top link. If my math works, that should be a second indication of what I can expect.

I havent got a clue what you were figuring there.

But to directly answer the question, the 4" splitter cylinder is going to be about 2.5x's more powerful than a pair of 1.75" cylinders. But it is also going to be 2.5x's slower. OR..about 38% of what the loader is.

Length does NOT effect the travel speed of the cylinder. But it will effect the cycle time. IE: if a 4x24 cylinder moves @ 3" per second, then a 4x30 is going to move the same 3" per second. BUT, its overall cycle time will be longer.

Back to the math. There are some good online calculators, but here is a crash course.

First, you have to find the AREA of the piston. I think you were refering to the rod earlier as the piston, which it is not. The piston diameter is what the cylinder is called. IE: your 4" splitter cylinder has a 4" piston.

To find the area, its Pi x R x R (or Pi x R-squared)

The radius of a 4" cylinder is 2. So 3.14 x 2 x 2=12.56 square inches. You can multiply that by the pounds per square inch (PSI) that your hydraulics is and it will give you the force.

Your 1.75" cylinders have a R of .875". SO, 3.14 x 0.875 x 0.875=2.40sq in. Times two cylinders is 4.80 sq in.....


so, 12.56/4.80=2.62. That means the 4" is 2.62 times stronger and 2.62 times slower in speed

 

[LD1]

Here is the calculators Baum Hydraulics Corp :: Spec Calculator

Assuming a 7gpm pump and a 4x24x2 cylinder, it will extend in 11.4 seconds and retract in 8.3 for a total cycle time of 19.7 seconds.

 

[BlueShibaura]

Here is the calculators Baum Hydraulics Corp :: Spec Calculator

Assuming a 7gpm pump and a 4x24x2 cylinder, it will extend in 11.4 seconds and retract in 8.3 for a total cycle time of 19.7 seconds.

That pretty well cuts to the chase. :thumbsup: It is actually very close to what I anticipated from eyeballing the chart on the last page of the splitter manual. Time will tell. Flying solo, I can live with the extended cycle time much easier than having to run this tractor at 540 PTO just to meet that 20 second cycle spec.

IF I wind up going the PTO pump route, will most 540 RPM pumps running at 270~ RPM be pumping at 50%~ of max flow? I have roughly 28 PTO HP to work with, and want to be sure I get enough pump to avoid high revs. Will the flow at 50% of the rated RPM differ between single and double stage pumps with the same max output rating? Is there a formula for that, or, if not, can you throw me one more bone on the most appropriate size(s) to consider for this simple set up? I really do appreciate your time fielding my ignorantly mundane questions. I will knock it off until I do more searching on my own.

 

[J_J]

I found these PTO pump for less. Prince pumps are on the same page.

PTO. Hydraulic Tractor Pumps

 

[LD1]

Yes, if you cut the RPM in half, the flow will roughly be 50%.

Actually when you start looking at pumps, you will notice that the often dont even give a GPM number. Only a displacement. Because flow is based off RPM, which can vary, but the displacement is a constant.

There are 231 cu-in in a gallon. So if you a pump with a 5 ci-in displacement, that means 5 cu-in of fluid for every revolution. spinning @ 270rpm, that is 1350 ci-in. 1350/231 is about 5.8 GPM. But that would be @ 100% effeciency. They are usually 85 or 90%. So...5.8 x 0.85 is actually going to be about 5 gpm running at half speed.

Actually, the way the numbers work out, running half of PTO speed will net you about 1gpm per 1 cu-in that the pump is rated.

About sizing it, you have 28hp at your rated PTO rpm. I am betting that it will be a good bit less if you cut the speed in half.

I think you said you have a TC30?? According to tractor data, it is listed @ only a 6.1gpm pump and 25hp at the PTO if you are gear and 24 if hst.

Realistically, you are probabally looking at about only 15HP to work with at the PTO speed of 270rpm.

Sizing a pump, the formula is: HP=(psi x gpm)/(1714 x %eff)

So....reversing that, we get (hp x 1714 x %eff)/psi= GPM

............................................(15hp x 1714 x 0.85eff)/2500psi= 8.75

So it looks like 8-9gpm is about all you are going to be able to do. Not much better than the tractor @ 6.1gpm, but thats the trade off for not wanting to run wide open.

If you ran full-power and 24hp....(24hp x 1714 x .85)/2500 = 14gpm. So you could about double the speed of the tractors pump if you ran wide open.

On the 2-stage pumps....I am not sure if I have ever seen a 2-stage PTO pump. But I could be wrong...