Do you get what you pay for with cylinders?

[the old grind]

Not to hijack, but do single stage pumps belong on splitters anymore? I've come to believe that they're the key to fast cycle times, lower hp requirements, and to some extent choice of cylinder, ie: so speed vs power isn't the same trade-off it is with a single stage pump. All hype, or what??

OP didn't mention splitting in both directions. Seems a two-way splitter could sacrifice quite a bit of power on retract, depending on rod diameter. ... OK that's getting OT. (sorry!)

 

[muddstopper]

Not to hijack, but do single stage pumps belong on splitters anymore? I've come to believe that they're the key to fast cycle times, lower hp requirements, and to some extent choice of cylinder, ie: so speed vs power isn't the same trade-off it is with a single stage pump. All hype, or what??

OP didn't mention splitting in both directions. Seems a two-way splitter could sacrifice quite a bit of power on retract, depending on rod diameter. ... OK that's getting OT. (sorry!)

I think it might be hard to find a factory made splitter with a single stage pump any more. Most of the manufacturers want to supply big tonnage numbers ,but keep the price of the splitter down low enough that they can sell it. Big problem with single stage pumps is its takes lots of hp to get the tonnage and speed and that cost money. I have built several splitters using single stage pumps. These splitters are usually built with scrap yard parts and on the cheap. Who needs a 25hp motor on a wood splitter? Well, If I find a good motor and pump cheap, then that is what I will use. My splitter might not be any faster, or have any more power than a factory splitter with a small engine and 2 stage pump, but I didnt pay $1000 for it either. I might pay the price in fuel consumption, but I dont use the splitter every day or split 100"s of cords of wood each year either, so I dont usually worry to much about fuel cost.

As for cylinders, Northern does have a 5x24x2in rod for around $239. This is the cylinder I am currently using. Its their house brand, but It seems to be doing all I ask of it. I like my cylinders just like I like my engines, big with lots of Umph!!! I am using a 28gpm 2stage pump as the 14gpm single stage I had was a bit slow for that size cylinder.

 

[LD1]

2 stage is where its at for splitting. Because in my experience, it only kicks to the second stage maybe 25% of the time. The rest of the time, it is in fast mode.

With a single stage, that isn't an option. So you have to size the motor according to max pressure, even though most of the time you require under 1000psi.

So if you are going to up size motors and sacrifice fuel, up size the 2stage pump...

 

[wdchyd]

I have also often wondered why they don't commonly make these cylinders with even larger rods. Like a 3" rod on a 4" cyl?? Not for strength, but speed.

.

The reason you don't find big hyd rods is the displacement ratio relates to increased return stroke volume in gpm...... For example,if the cyl displacement ratio is 2:1 then the return gpm that runs through the valve will be twice the output of the pump......if the valve core is not rated at the extreme gpm's then the two stage pump will sense the pressure drop and will cut back to the single stage or bog down the engine and will stall

On a typical installation of a log splitter with a large displacement ratio they usually use a single-pilot operated check valve mounted on a tee at a large port at the tail of the cylinder ( with a return line back to tank)..then they connect a pilot line to the retract port to sense the return pressure.......this method will allow most of the return oil to by-pass the main control valve instead of forcing it in through the valve core

 

[wdchyd]

I have a new cyl with the shaft extended that was left outside to the elements, and the shaft is rusted badly. To me that shows bad quality, but you would not know that until you had seen it or someone told you about it.

JJ, if you look at the industrial hard chrome plating with a microscope you will see that the chrome is actually porous......it's kinda like a stack of a billion sewing needles squashed down to .0005 to .001

The chrome plating actually gets it's rust prevention from running it in and out bathing the chrome in hyd oil.........even very expensive CAT and John Deere hyd rods suffer the same fate of corrosion under the chrome plating when idle for any length of time

use any kind of grease or oil spray to coat any exposed chrome when planning a seasonal layover

 

[lostcause]

I think it might be hard to find a factory made splitter with a single stage pump any more. Most of the manufacturers want to supply big tonnage numbers ,but keep the price of the splitter down low enough that they can sell it. Big problem with single stage pumps is its takes lots of hp to get the tonnage and speed and that cost money. I have built several splitters using single stage pumps. These splitters are usually built with scrap yard parts and on the cheap. Who needs a 25hp motor on a wood splitter? Well, If I find a good motor and pump cheap, then that is what I will use. My splitter might not be any faster, or have any more power than a factory splitter with a small engine and 2 stage pump, but I didnt pay $1000 for it either. I might pay the price in fuel consumption, but I dont use the splitter every day or split 100"s of cords of wood each year either, so I dont usually worry to much about fuel cost.

As for cylinders, Northern does have a 5x24x2in rod for around $239. This is the cylinder I am currently using. Its their house brand, but It seems to be doing all I ask of it. I like my cylinders just like I like my engines, big with lots of Umph!!! I am using a 28gpm 2stage pump as the 14gpm single stage I had was a bit slow for that size cylinder.

bingo. give this man a cigar. i power my little 3 1/2 x 18 splitter with a 24hp yanmar 3 cyl diesel and a 5-6 gpm single stage pump. in short order, i run it off my tractor's hydraulics. i built my splitter with a new cylinder, valve, hoses & fittings, but nearly all the steel was surplus / scrap cutoffs. i've got somewhere in the ballpark of $500 in mine (including the refinements and paint job i did this fall) and for my use it was a way better deal than a dedicated splitter. also, i'm sorry to digress and lead this off topic any more.

 

[MGH PA]

Alright, I didn't want to start another thread, so I will build off this.

Using this website to figure out line sizing to determine what valve I get (1/2" working vs 3/4" working), I'm having a little trouble understanding what velocity to use to determine the requirements. If I'm using a 16gpm 2-stage that runs a 3.5gpm @ 2500psi, will it be running at 16gpm (or close to it) for the return line, and the 3.5GPM initially on the suction? Just trying to think about how what sizes I will need for all four lines.

 

[J_J]

Try this nomograph .

Interactive Nomogram for Sizing Hydraulic Hoses

 

[MGH PA]

Try this nomograph .

Interactive Nomogram for Sizing Hydraulic Hoses

Yep, that's the one I'm using. I just don't know when to move the point on the right to 16gpm, and when to move it to ~3.5GPM. Usually, it's going to be low flow/high pressure on the suction, and high flow/low pressure on the return, right? What about figuring out the working lines? Are they under high pressure or low pressure most of the time?

 

[J_J]

Suction is a vacuum figure, but the hose should be strong enough not to collapse, and match the suction port size or larger.

Working hose only has pressure when working a load or maxing out the cyl, and should be rated higher than the pump pressure. Always use high pressure hose.

Your tractor hyd is probably not rated over 3000 psi.

Return lines usually have no pressure or little pressure, and use the same hose as the pressure hose.