Hydraulic help.. DIY mobile logsplitter

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Single pump driving a differential axle.. The pump is driven by the engine and then there are a few large diameter hoses to the drive. Then there are smaller diameter hoses to the lift valve (from the pump), with even smaller hoses from the lift valve to the cylinder.

The engine actually has another drive shaft on the flywheel end, this is the one that drove a large, heavy duty chain that drove the aerator gearwork.

So my best bet would be a new pump run off the flywheel drive? Is this getting close to costing me what a splitter would cost anyway?

Probably done till tomorrow.. have to go please the wife.. i.e. sit down and watch American Idol with her..
 
Sounds like a splitter pump could be driven off the front of the engine but the pump rotation direction will have to be matched.
Pics of the engine and pump are worth a thousand words.
 
First, thanks to everyone for the help so far! I was hoping I could turn this thing into a go-cart, but speed is really limited due to the hydrostatic drive.. I got the thing for $85, plus $10 to my buddy for gas.. so anything is win-win.. it was a hoot driving around at Halloween with our Mad Max theme..

So it sounds like I can't do much with the current hydraulic system. If I want to do anything it's best to try to run a new pump off the other side of the drive shaft? So I guess I'd need to mount a pump.. to include making sure it gets enough RPM and the correct rotation direction... need a new resevoir.. a new lift valve and cylinder, and the appropriate filter?
 
Sounds like you are heading in the right direction with a different pump but thought I'd post what the dealer tech sent about the specs. Hope some of this has helped.

GPM=
Cubic Inches of Motor or Pump x RPM

DIVIDED BY 231



The cubic inch I see for the pump is .91 cubic inch. assuming 3600 rpm =14.181 gpm theoretical
 
Bret Hart said:
The cubic inch I see for the pump is .91 cubic inch. assuming 3600 rpm =14.181 gpm theoretical
Click to expand...

Which would be quite workable with a 4" cylinder if the pressure is there. I am still not sure how you would divert the flow from pump to cylinder. A splitter/diverter would need to be in line because of the "open" system that is used by the splitters valve.
 
So do you think it's worth a try to get one of these (http://www.northerntool.com/shop/tools/product_472_472) and some suitable cylinder and try? I believe the inlet/outlet ports of the lift valve that is in there are 3/4".. and the work ports are 1/2".. maybe put a lever on the current lift valve, and just try a new cylinder?
 
Gareth96 said:
So I'd need two cylinders?
Click to expand...
??? No. That diverter would be to isolate the drive system from the log splitter. The hydro pump would supply one or the other at a time (but not both). The log splitter will be an open center system. If you leave that in the equation and try to drive off with the unit, the fluid will simply bypass in the splitters valve, not got to the motor (path of least resistance).
 
My guess is that you are also dealing with hoses and connections that may not be standard stuff found at your local tractor supply. You might want to check on that because some of that stuff can get pretty spendy in a hurry.
 
Actually, on the machine the two are separate.. the pump supplies the drive and lift cylinder separately. The drive would just be in neutral (or what ever the term is for the swash plate being in the middle) while splitting.

Or are you saying not to use the current lift circuit at all, just block that off and run the splitter in the same line as the drive?
 
The lift circuit is sized and plumbed for that tiny little cylinder on the back of that unit. I don't think it will have the capability to run a cylinder with 100 times the volume. (100 used for dramatic affect).

You will want to use the circuit with the highest volume/pressure and I would suspect that to be the drive circuit. We REALLY DO need to get the psi specs or this could be all for naught.
 
As an example...a 4" cylinder at 2000 PSI is gonna rate about 12.5 tons of force. Maybe this works for you, maybe it don't. That is your call.
 
If I'm looking at splitting logs no longer than 18" or bigger around than say 15", what would be a good cylinder for this?
 
If you look on page 95 of the manual, the symbol inside the lift valve box with 2000 psi under it is the symbol for a variable pressure limiting valve. If you intend to use that valve it may be adjustable with either shims or a screw adjustment.

I will try to find out more specs on the pump to see if it can safely handle the pressure increase.
 
Per page 95 in the manual, would the drive section of the circuit even have enough pressure? Seems like the drive is more flow, less pressure.. where the lift is lower flow, more pressure?
 
My opinion is that if you are looking to split 18" long splits you will want a 20" throat for a bit of wiggle room (trust me when I say that you will need a little wiggle room). I actually built a splitter with a 3.5" ram (designed to be a 12-15 ton unit for speed and I am running at 2700 psi) and it does pretty good on most stuff. Yes - I have stopped it. I used what I had, but if I had to purchase the cylinder I would have went with an 18" x 4". That would be a real nice combo and a good match to a 14gpm pump - again - assuming that the pressure is there.

Bret - thanks for looking up some of the specs on this things. It does help.

As said above...2000 psi on a 4" ram is 12.5 tons. 2500 psi on the same ram is 15 tons.
 
Gareth96 said:
Per page 95 in the manual, would the drive section of the circuit even have enough pressure? Seems like the drive is more flow, less pressure.. where the lift is lower flow, more pressure?
Click to expand...

And THAT, I am afraid, is that battle that you are going to be fighting. There is a reason that log splitters use a two speed pump.
 
Thanks again, Bret. One thing is for SURE is that you better have a good functioning relief valve in this system (as most splitter valves have). This is a positive pressure piston pump. It won't give up till something blows.
 
So what do you think my best option is with this new info?

- Give a try running a new cylinder using the current lift valve part of the circuit
- tap into the drive circuit and try running a new valve/cylinder, and one of those machine selector valves
- Use the other side of the drive shaft to run a whole new system off the 18hp motor
- Just buy a splitter...
 
Gareth96 said:
So what do you think my best option is with this new info?

- Give a try running a new cylinder using the current lift valve part of the circuit (probably not a viable option)
- tap into the drive circuit and try running a new valve/cylinder, and one of those machine selector valves (possible - I would confirm what we think we know with flow and pressure)
- Use the other side of the drive shaft to run a whole new system off the 18hp motor (May prove difficult because of counter-rotation concerns)
- Just buy a splitter...(lets discuss this)
Click to expand...

A few things that we DO know is this:
To build a splitter off of the platform for the Ryan machine it will require the purchase of a beam, a wedge, control valve, and plumbing hose (which again - could be a different style and require some expensive parts) The mount for the back end of the cylinder and a whole host of other things for bracing and building and don't forget the selector valve. Then ya get into the design side of the world. How is this going to be fit and finished to the Ryan machine? Off the back, along the side, etc. keeping in mind that you are dealing with heavy steel, this thing will need to be attached to framework. Do you want the need to go vertical? More engineering.

I don't know your comfort level or skill set to make this happen. Only you do.
 
I've got access to a beam & wedge material.. and a welder.. the frame of the Ryan is BEEFY.. 1/2" plate steel in areas of the aerator on back.. Will have to look to see if it's in the right location to mount a beam, but I believe it's doable. No need to go vertical..

I'll have to check the direction of rotation of the shaft.. but assuming it's in the correct direction to drive the majority of pumps, what do you think I'm looking at pricewise for the pump/valve/cylinder/resevoir/filter/pressure relief? And, again assuming all works out, how much better would this be than one that I could buy for a similar amount of money.. In other words, if I can build this for $500, how much better would it be than one I could buy for $500.. would I get a lot more tons, speed, etc?
 
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