Logsplitter trouble shooting

[J_J]

Just remove the sled from the cyl and manually move the sled back and forth to check binding, and also while the sled is disconnected, run the cyl in and out and check for loading.

 

[kered]

Thanks guys, i'll get onto what you have all suggested. The sled runs on a 10mm teflon/ptfe shim between the beam and the sled but it might be sticking. I also never thought of the breather in the tank, it only has a small hole in the cap. Don't have any guages but may be able to borrow for a test.
The strange thing is all i did was use a slightly bigger pump, before it was working great although slow.

This is a video with the old pump, First try, as you can see it was slow with the 10-12lt pump

I've also changed the blade

Derek

 

[J_J]

What kind of pump are you using that only runs at 1600 rpm.

What is the displacement and the rated GPM.

If you are coming off the PTO and through a 1.5 : 1, you are not close to the 1600 rpm for the pump you stated.

That means that your pump is running at 360 rpm.

 

[kered]

The reduction is reversed and its 3.5:1, maximum pump rotation is 2800rpm but you get almost maximum flow at 1600rmp, i'll check the make and model and let you know. Its a gear pump not piston.

Derek

 

[LD1]

I definataly got questions regarding the pump specs and actual flow. If the pump is rated for 2800RPM max, you are not going to be flowing nearly as much only running 1600rpm. So looking at a spec sheet would be helpful to us. As part of the formula for figuring out how much HP you need is GPM and PSI of the pump. And at this point, we know neither of those.

But "assuming" you are getting 9.25gpm and operating 2500PSI, that requires about 16HP. With a 30HP tractor, (probably around 24 at the PTO and a little less running through a gearbox) you should still have plenty of power for that flow and PSI.

So if you are stalling the engine (or nearly so), either you are making far more GPM than you think, or are generating more pressure than you think. Given that it is on the return stroke the only real pressure is when the cylinder reaches the end of the stroke. Most actual log splitter valves have a detent that kicks the valve to neutral one ~600psi is reached. It sounds like that isnt the case.

So aside from getting us more info on the pump specs, what is the make/model of the valve you are using? Is it spring return both ways? does it have the detent return? Does it stay in whatever position you put it in until you move it?

Some of the hose sizes are a little undersized as well, but shouldnt cause you to stall a 30hp tractor. Flowing 9.25 GPM 3/8" is a tad small. For pressure lines, 38" hose is good for 8-8.5gpm or so.

The return lines, when retracting the cylinder however, are trying to flow around 16GPM. which would want something in the 3/4" to 1" range.

But either way, regardless of hoses sizes, flow velocities, etc. If the pressure relief valve is set properly, there shouldnt be any stalling you your tractor. So whatever issue you have, is valve/pump related.

When splitting wood, it likely isnt taking as much pressure as you think. That is why you are only experiencing it when retracting and the cylinder bottoms out. Try extending the cylinder all the way till it bottoms out that direction and see if it is the same stalling situation.

 

[LD1]

I definataly got questions regarding the pump specs and actual flow. If the pump is rated for 2800RPM max, you are not going to be flowing nearly as much only running 1600rpm. So looking at a spec sheet would be helpful to us. As part of the formula for figuring out how much HP you need is GPM and PSI of the pump. And at this point, we know neither of those.

But "assuming" you are getting 9.25gpm and operating 2500PSI, that requires about 16HP. With a 30HP tractor, (probably around 24 at the PTO and a little less running through a gearbox) you should still have plenty of power for that flow and PSI.

So if you are stalling the engine (or nearly so), either you are making far more GPM than you think, or are generating more pressure than you think. Given that it is on the return stroke the only real pressure is when the cylinder reaches the end of the stroke. Most actual log splitter valves have a detent that kicks the valve to neutral one ~600psi is reached. It sounds like that isnt the case.

So aside from getting us more info on the pump specs, what is the make/model of the valve you are using? Is it spring return both ways? does it have the detent return? Does it stay in whatever position you put it in until you move it?

Some of the hose sizes are a little undersized as well, but shouldnt cause you to stall a 30hp tractor. Flowing 9.25 GPM 3/8" is a tad small. For pressure lines, 38" hose is good for 8-8.5gpm or so.

The return lines, when retracting the cylinder however, are trying to flow around 16GPM. which would want something in the 3/4" to 1" range.

But either way, regardless of hoses sizes, flow velocities, etc. If the pressure relief valve is set properly, there shouldnt be any stalling you your tractor. So whatever issue you have, is valve/pump related.

When splitting wood, it likely isnt taking as much pressure as you think. That is why you are only experiencing it when retracting and the cylinder bottoms out. Try extending the cylinder all the way till it bottoms out that direction and see if it is the same stalling situation.

 

[J_J]

The reduction is reversed and its 3.5:1, maximum pump rotation is 2800rpm but you get almost maximum flow at 1600rpm, i'll check the make and model and let you know. Its a gear pump not piston.

Derek

How did you figured the 2800 rpm pump would provide max flow at 1600 rpm

If the pump max flow is at 2800 rpm, why are you running it at 1600 rpm.

540 PTO rpm through the gear box increases the pump rpm to 1850.

Seems to me , you are running the pump at about 66%.

 

[kered]

I have 2 speeds on the pto, 545 and 760, I was told the pump data at the shop as they have the speck sheet in the cataloge which we consulted looking for the most appropriate pump, working pressure is 200bar(2900psi) with max at 250bar(3625psi) from 1600rpm up over the flow doesn't increase much, no idea about 66% but i don't believe running anything at 100%
I don't have any speck on the control valve only that it has 1/2" ports and is manual spring loaded both ways, no detents,i prefer it like that so that as soon as i let go everything stops and it was something i already had on the shelf.

I've opened the tank filler, oiled the sled with very little difference but i did try to stall the engine by not letting go of the lever as the engine slowed and it didn't stall, just dropped to tickover so maybe that has something to do things as a very slight movement on the hand throttle speeds the engine up quite a bit from tickover. I'm off to try and scrounge some pressure meters.

Derek

 

[kered]

OOps forgot, tractor is 28hp at pto
I don't expect to get the full 35lts- 9.25g/m hense the reasoning that going to 3/4 was overkill
Moving cylinder to full extention just opens the relief valve, no engine stall on the push stroke(i have it set pretty low)as soon as i pull the lever to return the revs drop, long before i hit the fully retracted but its not fully stalling the engine.
Maybe i'll do a short video as a picture paints a thousand words

Thanks to all for the input its really appreciated

 

[LD1]

So you are saying that going forward till the ram stalls and opens the relief and the tractor runs fine and dont bog, but on the return stroke, even with cylinder in mid stroke and a long way from bottoming out, the tractor bogs alot?

IF that is the case, where is the pressure relief? is it on the valve or pump? IF on the valve, it could have a different setting for each direction. IF on the pump I am unsure why it isnt operating the same as going forward. But in either case, the retrun lines are undersized. While it may or may not be causing the issue, it certainly isnt helping the cause.