Portable Hydraulic power unit

rus_geek · Dec 21, 2009

What log lift/grapple are you looking to run with this setup? Did you pick up the Anderson you were asking about?

-r-

ahlkey · Dec 21, 2009

I am familar with the Anderson units (almost bought a used one early this year) but finally bought a used Metavic log loader/grapple which has performed well.

I found a used log/splitter locally this morning that has a 18HP Honda engine on it and they claim is only a few years old but the splitter/ram itself is probably over 20 years old.. I am going to take a look at it and see if it would work for me as it would be far less expensive than builiding one from from ground level zero. Thanks JJ for the information on using a relief value & control value as I am pretty sure this 18HP will put out more PSI and GPM than I need which would not be a good thing. Thanks again.

J_J · Dec 21, 2009

The 18 HP would work just fine, and put out whatever the pump is designed for. GPM's would be around 9, @ 3000 psi on a single stage pump. On a two stage pump, you might get , 28 GPM's @ 650 psi, and 7.5 GPM's @ 2500 psi

On a single pump 9 GPM , @3000 psi, a 5 in cyl, 2.5 shaft, = 30 ton 12 sec split time
two stage pump @ 28 GPM-------------------------------------6.7 sec split time.

ahlkey · Dec 21, 2009

I wasn't able to get away today to look at the splitter so not sure what type of pump it has but I do know it is an older model pump maybe 20 plus years. I plan to drive over tomorrow so it is good to know the limiting factor of the output is the overall pump. The 18 HP Honda is the not the original engine on it but they had it availabe and it was only a few years old so they used it. They say everything works well. In any case, not sure I will be able to figure out if the pump is single or two stage? Any advice on how one can tell either way? All I know is what the manufacturer told me on my Metavic loader namely that I should not have higher or lower than 2300 PSI if I want optimal performance. They did not seem too worried if the GPM is between 9-12 GPM for that matter but recommend 8 GPM. Thanks again.

George G · Dec 21, 2009

Just remember, you don't use two stage pumps on anything you want to control. Like backhoes, frontend loaders, grapples, dump trucks, trailers or wagons or whatever. Only use on things that total control is not needed, like log(wood) splitters, compactors, don't know. Can't think of anything elce. But anyway, see what I'm saying.

ahlkey · Dec 21, 2009

Thanks for the heads up. I still don't know if I know the difference betweeen single and two stage pumps by looking at it but maybe their will be some sort of identification on the pump.

J_J · Dec 22, 2009

Irregardless what kind of pump you use, the tonnage rating on a 5 in cyl will be the same, with same psi. Most all free standing log splitters use a two stage pump, and the 3PT log splitters use the tractor hyd which are high pressure, and whatever volume the tractor is rated for. The pressure gives you the force, and the volume gives you the speed of the cylinder operation. If you have a hyd cyl with a rating of 3000 psi, then you can use up to a 3000 psi pump. Anything less will simply provide less power. It is difficult to know what an unknown pump is, but two stage pumps usually look like the one below. One way you can tell whether a pump is two stage is to connect it to an engine and run it with a gage on it. If the initial pressure on it is about 650 psi, and then jumps to 2500 psi when pump is working very hard, then it is probably a two stage pump. Actually, a pump will read zero or very little pressure if there is no resistance to the hyd flow.

https://www.surpluscenter.com/sort.asp?UID=3880122117181523&catname=hydraulic&keyword=HP2S

skidsteer.ca · Dec 23, 2009

George G said:
Just remember, you don't use two stage pumps on anything you want to control. Like backhoes, frontend loaders, grapples, dump trucks, trailers or wagons or whatever. Only use on things that total control is not needed, like log(wood) splitters, compactors, don't know. Can't think of anything elce. But anyway, see what I'm saying.

I agree a 2 stage pump on a loader would be very jerky to operate. The pump would be often switching back and forth between high and low flow.

Say you pick somthing up and start to swing it. The lift would switch the volume to low for power, and the swing takes very little pressure. So now you're swinging slow and let go of the lift because you have it high enough, the swing would now take off like a rocket because wheen the pressure drops from below 650 psi the flow increases 4x.
Just something to consider.
Ken

ahlkey · Dec 23, 2009

It looks like the log splitter idea is not going to work for me. This splitter is very big and it has a two stage pump. I guess I am back to looking for a used portable one, buying one, or making it myself. I am going to check out a local guy who builds them but not sure what he will charge.