Hydraulic log splitter spool valve questions

[jff45]

I've bought a secondhand 16 ton hydraulic log splitter and I'm not happy with the way the spool valve works. It has no centre spring detent and the spring bias is to retract the cylinder ram.
It's been crudely made so that the axe head hits a bar which in turn pushes a rod connected to the spool valve so that spring loaded lever is forced to the centre position and thus cuts the pressure.

I see that most log splitters now have a valve with just a single lever that has a centre spring detent so you can let it go at any point in the down stroke and the axe head will stop at that position. When you push the lever (this is my understanding) to retract the axe head/cylinder ram, it stays in position without springing back to centre until the ram is fully retracted and then the excess pressure pushes the lever to the centre.

Does anyone on here have good knowledge of what's required for a log splitter?
I've seen some valves mentioned as 'not suitable for log splitters' and I'm guessing it's because the valve will release to a bypass when there's too much pressure - as would happen if you need to insist with a particularly hard piece of wood.

Geez, that's a bit long-winded for a simple question.. sorry about that :)

[BigRAWesty]

A valve by itself souldnt release pressure unless you physically overload the valve. Which then you have bigger issues..
Imo you simply want a 3 position 4 port valve which returns to tank in center and return to center lever..
This will hold in either direction in or out and just simply flow back to tank when in the center..

[jff45]

The log splitter ram needs a 4 port valve because you need 2 working ports to extend then retract.
The auto return to centre action isn't really practical when you operate the splitter by yourself. You need to be able to keep your hand on the lever to split and let it release to centre when it's done but then you need to be able to push the lever to retract and not have to hold it while you move/replace your wood.
In most cases, because it retracts slowly, you'll catch it for the next split before it gets too high but if you don't it will be set back to centre by the detent pressure anyway when it fully retracts.

The current system I have does it mechanically but it's a mess of bars and levers that I'd like to modify.

There shouldn't be any great issue with overloading a valve. I have a Kubota tractor with a front end loader and I often curl the bucket too much and it makes the over pressure valve scream a bit when it releases pressure but that's what it's designed to do.

[nissannewby]

I work at a hydraulics company in brendale mate if your interested you could PM me and we can discuss your needs. You could also come in.

[nissannewby]

All you really want is a control valve and a cylinder that will max out its stroke at the base of the splitter. Then control is up to you there are about 100 options you could from basic manual operation to remote control with proxys :).

[BigRAWesty]

The log splitter ram needs a 4 port valve because you need 2 working ports to extend then retract.
The auto return to centre action isn't really practical when you operate the splitter by yourself. You need to be able to keep your hand on the lever to split and let it release to centre when it's done but then you need to be able to push the lever to retract and not have to hold it while you move/replace your wood.
In most cases, because it retracts slowly, you'll catch it for the next split before it gets too high but if you don't it will be set back to centre by the detent pressure anyway when it fully retracts.

The current system I have does it mechanically but it's a mess of bars and levers that I'd like to modify.

There shouldn't be any great issue with overloading a valve. I have a Kubota tractor with a front end loader and I often curl the bucket too much and it makes the over pressure valve scream a bit when it releases pressure but that's what it's designed to do.

Sorry yes you are right in saying 4 port, but it's not 2 for each,
It's a feed for either end, to tank and ofcourse pressure..
So I've edited my post..

[jff45]

I work at a hydraulics company in brendale mate if your interested you could PM me and we can discuss your needs. You could also come in.

Cheers mate, I'm pretty sure I know what I need now after a bit more research and I don't want to be throwing big money at a $400 used tool.
I can get the valve I want for ~$90 in the US. One of my boys lives over there.

[jff45]

The splitter I bought is basically identical to this one I found online. You can see the 2 handles that need to be pulled together to make it extend the ram.

http://i257.photobucket.com/albums/hh207/JFF45/Turbo%20install/Misc/IMG_1662_zps1989abaa.png


This is the valve it has on it.

Can anyone tell me what the bottom left item is? I'm pretty sure it's an adjustable detent but I can't understand what it controls if the valve is spring biased one way only.

http://i257.photobucket.com/albums/hh207/JFF45/Turbo%20install/Misc/IMG_1668_zps8d911c4a.jpg

[nissannewby]

If the hose above it goes to tank then its a relief valve.

[nissannewby]

Basically you will have a feed from the hydraulic pump to your valve then the 2 centre ports are you directional which will go to your cylinder. Then the valve has it's relief and the hose above it goes to tank.

[jff45]

Basically you will have a feed from the hydraulic pump to your valve then the 2 centre ports are you directional which will go to your cylinder. Then the valve has it's relief and the hose above it goes to tank.

The pressure from the pump is coming in on the left in that pic i.e where the little blue ID tag is.

[nissannewby]

The pressure from the pump is coming in on the left in that pic i.e where the little blue ID tag is.

Yep still a relief valve mate I didn't really word that right. It basically controls the max pressure allowed in your circuit.