Making sense of log splitters and tonnage

[Badfish740]

I've been looking at splitters lately and I've seen everything from 8 to 35 ton ratings as well as everything in between. Obviously there's a big price difference between the 8 ton and the 30 ton, so just how much force do I need? I'm a scrounger so I get whatever I can-no particular type or size of wood. I'm guessing that an 8 ton might not be enough and a 30 ton might be overkill-should I just aim for the middle?

 

[Adios Pantalones]

I don't know for sure, but I bet the tonnage rating ends up a lot like horsepower rating- not every manufacturer is super honest on their ratings. I have a 33 ton TryBilt that does quite well for me, but people here report great results with units in the 20-24 ton range.

 

[kevin j]

quick notes:
-have to define usages, type of wood, etc and think through all that.

-Most of the 'tonnage' numbers are marketing BS. It is far easier to compare tons than sort out all the technical features, so the marketing people have to one up the other companies: 22 tons? we will market ours as a 24 tons.....

Tons is OPERATING pressure times cylinder area. Many mfrs use 3000 psi or 3500 psi or some rated maximum of one single compenent, or even higher fictitious numbers, even though the relief valves are set at (usually) 2500 psi. Regardless if there is a 10,000 psi rated cylinder, if it operates at 2500 psi, that is the max force.

Cyl Bore inches 3 4 4.5 5
Tons push at 2500 psi 8.8 15.7 19.9 24.5
loses columns formatting...


-Of all the ones I have used, speed is my frustration, not tons. I don't get much big stuff here, 24 inches is pretty big, so a 4 inch cylinder is quite fine. Bigger stuff, carve from the sides, or quarter with the bigger saws before putting on the splitter.

-4 inch cylinder is good mobile machine homeowner use. 4 inch cylinder is 16 to 22 tons.
4.5 or maybe 5 inch cylinder for woodlot use,

-My preferences: get 8 to 12 hp, 16 or better 22 gpm, and 4 inch cylinder for speed.

k

 

[Adios Pantalones]

Kevin- With just me operating in a rhythm, slow works out OK. (gives me time to throw splits, fetch the next log, etc.)

I was using my splitter yesterday thinking- if I had another person working with me, then this could be a lot faster.

 

[Catskill]

With out knowing your specific circumstances I'd say aim for the 20-24 ton range. A machine like that will split 95% of what the average Joe sees for wood.

 

[Corey]

From: https://www.hearth.com/econtent/index.php/forums/viewthread/25622/

It will depend some on how much and what type of wood you plan to process. If you’re looking for a cord or two of oak or maple per year...that stuff practically falls apart - you could probably get by with something on the small end of the scale. If you want 3, 4, 5 or more cords of elm or some other knotty, twisty, hard to split wood, you might as well get something on the large end or you will be cussing all the time and heartache you spend with an under powered splitter.

It’s also been my observation that the splitter power curve is really logarithmic - that is a 5 ton splitter will probably split 90-95% of your wood - maybe more if you cut it carefully to begin with. A 10 ton splitter may do 95-98%, 15 tons will do 99%, 30 tons may do 99.5%. But getting a lot bigger splitter doesn’t get you a lot more split wood - just insures that you can take on those few very hard to split pieces.

With that said, my splitter tops out in the 17-19 ton range. I don't know when the last time I had to cut a piece vs split it was. I kind of know what will split and what won't - so when I'm out cutting wood, I have a pretty good idea how to cut to make a splittable piece. If I run across a really bad crotch or side limb, I'd probably just go ahead a cut a section 6" thick or so - which will fit in the stove and save me the headache of trying to split it.

 

[Gooserider]

Basic rules

1. - Cylinder size determines the force, at a nominal 3,000 PSI maximum pressure (which you'll almost never see) 4" = 18.5 tons (usually rounded to 20) 4.5" = 23.9 tons (rounded to 24 or 25) 5" = 29.4 tons (rounded to 30)

2. - The common 2-stage pumps used on most splitters will determine the splitter speed / cycle time. The number you will see advertised is the high volume, low pressure range that the pump operates at most of the time, up to around 800psi. When you hit the tough stuff, it will go into low volume, high pressure range automatically, which will produce up to 3,000psi at about 1/4 the rated gpm - this is what gets you through the knots and crotches... You can put any size pump on any cylinder and it will work, but the speed will differ.

Typical combos for homeowner machines, - 5hp - 11gpm - 4"; 6.6hp - 13.5gpm - 4.5"; 8hp - 16gpm -5" for commercial machines bump the engine and pump sizes up one or two notches for a given cylinder to increase the speed.

3. Engine horsepower is almost irrelevant, as long as it will drive the pump in low range, which takes about 2hp per gpm, or about 1/2 hp per gpm or a little over (remember the engine makers stretch their numbers as well) in high speed.

Gooserider

 

[SolarAndWood]

I have read the splitter posts with interest and was curious about the effectiveness of the electric motors. This weekend I did a very crude experiment with an old light duty splitter that has been waiting for either a new engine or rebuild for many years. I replaced the old 5 hp gas with a 230V 2hp/3450 rpm electric of unknown origin/condition that my father in law had in his basement. I only had 120V convenient, so that is what I used. I am amazed at how well it worked and how quiet it is.

A few questions as I know little about electric motors or hydraulics:

I assume that because the motor stalled without the breaker blowing that the motor will not draw more than 10 amps regardless of voltage? Feed it 230V, get more power?

I have seen for example the Ramsplitter uses 2hp up to 16 ton and 3 hp on their 20 ton units. Given Goosriders post above, this would seem to imply that 2 hp electric replaces 5 hp gas, and 3hp electic replaces 8 hp gas? So, if I want to repower my big splitter that uses a 25 hp Wisconsin, I need to shop for something on the order of a 10 hp electric?

It is not my intention to refire the electric vs gas debate; electric works well for me as all of my scrounged wood comes home blocked and gets dumped directly adjacent to my woodshed. I am looking to build a permanently mounted electric powered 8 or 10 way capable splitter that drops the splits through a hole about 6 feet up the back wall of my shed.

Thanks for your help and ideas.

 

[computeruser]

A 4" cylinder will split damned near anything you'd want split. Whether you need/want more is up to you and your circumstances. I've been pleased with my little Timberwolf, largely because it is compact and weighs around 400lbs, which means I can move it around the yard and in and out of the trailer, all by hand.

 

[triptester]

If the electric motor was built for 220 volts only and you try to run it with 110 volts the motor will eventually burn out. You are only using half the windings.
The size of motor require depends on pump size. A 8 or 10 way wedge will require at least a 5" bore cylinder.

 

[smokinj]

Kevin- With just me operating in a rhythm, slow works out OK. (gives me time to throw splits, fetch the next log, etc.)

I was using my splitter yesterday thinking- if I had another person working with me, then this could be a lot faster.

2 people is the fasest done it with 3 but the 3rd person will slow you done some

 

[SolarAndWood]

The size of motor require depends on pump size. A 8 or 10 way wedge will require at least a 5" bore cylinder.

My big splitter has a 5" on it. It has a 4 cylinder Wisconsin out of an old Bobcat that I think is rated for 22hp. With that motor/pump combo, it has a very short cyle time with the single wedge no matter what it is splitting. Any idea what flow/pressure I will need for the 8 or 10 way?

 

[Gooserider]

The size of motor require depends on pump size. A 8 or 10 way wedge will require at least a 5" bore cylinder.

My big splitter has a 5" on it. It has a 4 cylinder Wisconsin out of an old Bobcat that I think is rated for 22hp. With that motor/pump combo, it has a very short cyle time with the single wedge no matter what it is splitting. Any idea what flow/pressure I will need for the 8 or 10 way?

What's the pump spec? GPM, single stage or two-stage? Note that unless it's an unusual cylinder, with matching pump, hoses, and other hardware (very unlikely) you will NOT get more than 3,000psi at the cylinder, MAXIMUM... Putting a different wedge on won't change it in the least, except that the logs will now be harder to split as you'll be dividing the same tonnage between multiple splits (minimizing this is why most multi-way wedges are staggered so that different edges hit the round at different times)

My observation of the pressure guage on my 30 ton, 5" cylinder machine is that even gnarly crotches rarely need more than about 1800psi with the single wedge on my unit. Assuming you have a pump / motor combination such that the motor can drive the pump at 3,000psi output (at which point you should be going into over-pressure bypass) w/o stalling, then you should be seeing the same flows and pressures, except that the motor will work a little harder, and the pump may kick down into low range (if it's a two stage pump) a bit more often.

Gooserider