Three Point Log Splitter

[Green Mtn Boy]

I'm thinking about getting a wood splitter for my Kubota 3830 but I've never used a tractor mounted wood splitter. I believe I would need to go with the PTO pump because the factory hydraulics don't have enough flow or pressure to power a splitter efficiently. PTO pumps seem to be much more expensive then the normal two stage pump made for gasoline powered splitters. They also seem to have less operating pressure ( I think because there not two stage) but GPM seem to be high, netting fast cycle times. Most are designed for 540 RPM as compared to 3000 RPM gasoline powered pump...... do they have the force of a gasoline powered splitter? If I did the math correctly, with the pump being single stage running at 2200 psi max the cylinder would need to much larger to create as much force as a two stage pump running at 3500 psi max. Anyone have experience running both? Would it be possible to use a two stage pump and run it via pulleys of the PTO to achieve near 3000 psi?

 

[ManiacPD]

We have a home made one we use on the farm that runs off the tractor hydaulics. It is very slow as you mentioned, even when we used it on the 95hp Kubota. Splitting force is there though, no question. I saw one in Northern Tool that mounts to a 3ph and works in two directions which would help make up for the slower cycle time.

http://www.northerntool.com/webapp/wcs/stores/servlet/product_6970_200365528_200365528

 

[Highbeam]

Just get the unicorn for your tractor like I use! Not. Those things are nuts. I use one for now but I don't like it.

You really should consider just buying a standalone splitter with its own engine. The wear and tear on your very oversized tractor is one factor along with fuel consumption and convenience.

Those prince pumps are almost 500$ by themselves and then you need to consider a hydraulic tank since the tractor hydraulics aren't being used. Lots of plumbing, valves, the ram, etc. Many folks have determined that you'd be better off with a stand-alone.

 

[jdemaris]

They also seem to have less operating pressure ( I think because there not two stage) but GPM seem to be high, netting fast cycle times. Most are designed for 540 RPM as compared to 3000 RPM gasoline powered pump...... do they have the force of a gasoline powered splitter? If I did the math correctly, with the pump being single stage running at 2200 psi max the cylinder would need to much larger to create as much force as a two stage pump running at 3500 psi max. Anyone have experience running both? Would it be possible to use a two stage pump and run it via pulleys of the PTO to achieve near 3000 psi?

I'm not sure about the pressure-concerns you mention. Most factory-built splitters with two-stage pumps max-out at 2300 - 2500 PSI via the relief-valves and run 650 PSI on the low-stage - NOT 3500 PSI at high. Many if not most hydraulic cylinders are only rated for 2500 PSI or 3000 PSI and that is the maximum rating - not really the preferred full-time use rating.

PTO pumps are usually rated at 2500 PSI which is all you need. A PTO pump with a 4" cylinder will split just about anything, and a PTO pump with a 5" cylinder at 2500 PSI, will indeed, split any wood known to man - even hard-maple, curly, stump-wood.

A tractor tends to have more extra horsepower available, so it can run a single state pump with no trouble. Main thing is - size it right so you can run with modertately low engine RPM or under a slight load. Otherwise, you can use a lot more fuel than you need. A big tractor not being worked hard can waste a lot of fuel.

A PTO pump that can flow 7 gallons per minute at 2000 PSI needs 12 horsepower.
A PTO pump that flows 13.5 gallons per minute at 2000 PSI needs 23 horsepower.
A PTO pump that flows 22 gallons per minute at 2000 PSI needs 35 horsepower.

I've got two 3 point splitters with PTO pump and also a self-powered splitter with a 14 horse engine and two-stage pump. I prefer the tractor 3 point setup - it's a lot handier. For big wood, I can drive it right into the woods and split on-site when needed.

My lowest power tractor is an IH B-275 diesel - 32 horsepower, with a Prince HC PTO-9A pump and a splitter with a 4" cylinder and it will split 99% of anything I cut - and I cut just about all large hard maple and pignut hickory. I also have a splitter with a 5" cylinder that will indeed split anything. I've also used it as a hydraulic press for other jobs.

 

[Dill]

I've always run 3pth splitters off of tractors. A lot depends on the gpm rate of your pump. My old IH is a 16gpm pump and it'll split right along. But we tried the same splitter on a friend's IH with 8gpm pump and it was wicked slow. I look at it this way. Its cheaper than a standalone and I don't have keep 1 more engine running.

 

[RPK1]

I'm thinking about getting a wood splitter for my Kubota 3830 but I've never used a tractor mounted wood splitter. I believe I would need to go with the PTO pump because the factory hydraulics don't have enough flow or pressure to power a splitter efficiently. PTO pumps seem to be much more expensive then the normal two stage pump made for gasoline powered splitters. They also seem to have less operating pressure ( I think because there not two stage) but GPM seem to be high, netting fast cycle times. Most are designed for 540 RPM as compared to 3000 RPM gasoline powered pump...... do they have the force of a gasoline powered splitter? If I did the math correctly, with the pump being single stage running at 2200 psi max the cylinder would need to much larger to create as much force as a two stage pump running at 3500 psi max. Anyone have experience running both? Would it be possible to use a two stage pump and run it via pulleys of the PTO to achieve near 3000 psi?

I beat this around for quite a while. The "Tractor by Net" guys talked me into getting a stand alone gas powered splitter. True it is one more engine to maintain but I have the bucket of my L3130 right next to the splitter and load it up as I split. I don't have rear remotes on my tractor so it was almost cheaper to buy a stand alone splitter. Just my 2 cents.

RPK1

 

[jdemaris]

I beat this around for quite a while. The "Tractor by Net" guys talked me into getting a stand alone gas powered splitter. True it is one more engine to maintain but I have the bucket of my L3130 right next to the splitter and load it up as I split. I don't have rear remotes on my tractor so it was almost cheaper to buy a stand alone splitter. Just my 2 cents.

RPK1

Well, if you are only talking about buying new - it makes sense. But, three point splitters tend to sell very reasonable since not everybody has a tractor to run one. I bought my big one (with 5" cylinder) with the PTO pump for $500. The smaller one - with a 4" cylinder also came with a PTO pump and I paid $350 for it.

I've got an self-contained splitter and also the two 3 point hitch units - and I never use the self-contained splitter anymore. The three-point splitters are a lot handier, faster - and I've got 6 tractors here. I never have to worry about getting a splitter engine going that's been sitting for a year (now more).

Also - about speed. A 5" cylinder with a 24" stroke only holds around 1 1/2 gallons. So, a pump that makes 7 gallons a minute at 2000 PSI will make the cylinder cycle in a second of two which is plenty fast.

 

[Dill]

One other advantage is its easier to get the splitter to the wood. I have a horizontal and my father has a vertical. The vertical is nice with really big stuff, you can back the splitter under the chunk. But after using my horizontal for while I think its the better choice. With the 3pth I can drop the splitter down level with the ground and roll chunks up on it. I paid 350 for mine used and my father's was 600 new.

 

[Gooserider]

<snip>Would it be possible to use a two stage pump and run it via pulleys of the PTO to achieve near 3000 psi?

One thing I haven't seen mentioned was this question, the answer is yes, but you will need to be careful - most of the two stage Haldex/Barnes pumps used on splitters are designed to ONLY be used with an inline drive, and can't take side loads... No problem with most designs that have a direct connection w/ a lovejoy coupler to the engine crankshaft, but if you want to use a belt it is necessary to have some extra support on the shaft, or have a supported jackshaft that is connected to the pump w/ a lovejoy to isolate it...

Gooserider

 

[jdemaris]

<snip>Would it be possible to use a two stage pump and run it via pulleys of the PTO to achieve near 3000 psi?

. . . the answer is yes, but you will need to be careful - most of the two stage Haldex/Barnes pumps used on splitters are designed to ONLY be used with an inline drive, and can't take side loads...
Gooserider

3000 PSI is not a good goal. At that pressure - at best - everything is being worked to the max. That is a bad way to design something. Even high-end industrial and farm tractors, backhoes, excavators, etc. rarely run past 2200 PSI. That so things last awhile. I'll add that many cylinders are only rated 2500 PSI for max. safe pressure. The reality is - 2200 PSI, or even 2500 PSI - in a log splitter can split anything with the proper cylinder.

There are plenty of single and two stage pumps available with full ball bearing support for side-load belt drives. Dynamic makes two-stage ball-bearing pumps from 8 GPM up to 16 GPM for less then $130. But, that's 16 GPM at 3600 RPM and in low-stage (fast mode) pressure of 650 PSI.

A two-stage pump would be pretty useless on a PTO running at 525 RPM. Also doesn't make much sense unless you've got some sort of overblown garden tractor. A real tractor, or even a compact tractor with a real 525 PTO is going to be, at least, close to 20 horsepower.

If you were to take a big two-stage pump - let's say a 28 GPM model for over $400. Then, hook it up belt drive to a 525 PTO with a 1 to 1 ratio - that pump will only put out 4 gallons per minute in fast-range, and only 1 gallon per minute in low range (high pressure).

Then there's the added issue of belt-slippage. And, if you try to speed the pump up by using a smaller pulley on it - the belt has less friction area and slips that much more.

Maybe I'm missing something - but if you have a farm-type 525/540 PTO, stick a PTO single-stage pump on it and you'll do fine.

If you buy a single-stage PTO pump - often marketed as 8 GPM, it will flow around 7 1/2 GPM using 3 horsepower at 500 PSI. When you hit hard wood - and pressure rises to 2000 PSI - flow will drop to 11 GPM and you'll need 12 horsepower. At 2500 PSI - you'll need around 15 horse.
At 2500 PSI, a four-inch cylinder will split just about anything, and a 5" cylinder WILL split anything.

One a side-note, I still have a splitter I made 35 years ago - from junk parts. It has a single-stage Cessna aluminum pump (not ball bearing). It's hooked via belt drive to an 8 horse S8D Wisconsin engine with a 6-1 ratio. So, when the engine runs 3600 RPM, the pump only runs 600 RPM. When I built it, I already knew how fast it would run - since I built it from parts I robbed off a John Deere 450 crawler-loader with 5" cylinders. I knew how fast they cycled with engine idling - so no math needed. Cycle speed is a little slow but OK. It will split just about anything with the 5" cylinder - but in hard stuff will either slip the belt or stall the engine - unless you "surge" by hitting the lever quick and then, let off. It is a crude piece of junk. At the time when I threw it together, I didn't expect it to last a year. Pump, valve, tank, filter, and cylinder all came off the Deere crawler. Engine came off a Bolens garden tractor, beam made from a piece of railroad track, and wedge made from two crawler-grouser pads welded together.
Like I said, a piece of crap - but also proof of what an 8 horse engine can do with a single-stage pump and a large cylinder. It got used a lot for 3-4 years, and now it's just parked in my "archives" out in the field.

 

[firefighterjake]

Sometime when I think of it I should take a photo of the splitter my Dad made back in the late 1970s/early 1980s. He built it on the cheap out of parts he scavenged and it's still going strong today although he has modded it over the years to suit his needs. The reason I think you guys would get a kick out of seeing a picture of it is due to the fact that his most recent modification was to attach it sideways to the front of an old horse-drawn manure spreader. It sounds (and looks) ridiculous, but it actually works out pretty well for him since he can drive up to the woodpile, split the wood and then toss the splits into the spreader/trailer . . . and then when he gets to where he wants to unload the wood he can either unload it a piece at a time or he can engage the old manure spreader's chain/sprocket unloading mechanism by hand which pulls the wood back to the open end where he can get at it more easily.

 

[Gooserider]

I agree, 3,000psi isn't the best pressure to work at most of the time, but it does seem to be the pressure stuff is spec'd at... If you look at the tonnage you can get from a cylinder of a given size, you need to be at or a bit above 3,000 to get the tonnage, and even then it's a bit low... A 4" cylinder, as found on "20 Ton" machines only does 18.5 tons @3,000, and a 5", normally sold as a "30 Ton" only makes 29.4 @ 3,000....

Not that it makes a huge difference, as you pointed out, most anything will split at far less pressure than that. I haven't seen my HF splitter get above about 1800psi doing a split yet, but it will over-range my 3,000psi pressure guage if I hold the lever at the end of the cylinder travel... One of these days I need to fine tune the pressure relief.

Gooserider