Log Splitter tonnage rating - are they on crack, or just lying?

[mga]

following all this...i checked some web sites for the parts i am using on my splitter. to achieve the maximum desired tonnage, your pump, control valve and cylinder must be "tuned" with each other...for lack of a better word.

i am using a prince LS-3000 control valve with a maximum factory setting of 2750 as you can see at this link:

http://www.princehyd.com/Default.aspx?tabid=46

the pump i am using is a haldex two stage as you see here:
http://www2.northerntool.com/product/200321057_200321057.htm

the pump, according to the haldex web site, has a maximum pressure rating of 3000 psi. so, regardless what my pump says, the final word is the controller setting....correct? therefore, is it not true that my controller, in this case, is actually robbing me of power?

wouldn't i have been better off using one of the 3000 psi rated controller valves to give my 5" cylinder the maximum pressure?

so, i wonder if they intentionally did this lower setting because it's on a log splitter...which in most cases are probably home built...as a safety precaution?

 

[DanMan1]

The measure given is tons which is a measure of force. Hence contact area has nothing to do with it. Contact area is only important if you are talking about pressure

Bingo:jester:

 

[CaseyForrest]

But isnt it easier to "Force" 22 tons onto a smaller contact area? The edge on your wedge has got to have something to do with it.

If you have a knife edge on your wedge, compared to a rolled over egde, the knife edge is going to split with less force than the rolled edge, correct?

Disclaimer: I am not a mechanical enginer, physicist, or rocket scientist. Just trying to also understand how manufactures come up with their inflated numbers.

 

[dtw902]

The tons rating would be max output, say against a flat block.
The wedge just makes it easier to split with less force.
You are not using max tonnage to split, only on knotty, gnarly
wood.
When the cylinder stalls it is pushing max tonnage for a given
system.

 

[BlueRidgeMark]

Here is another link for ya BlueRidgeMark.
http://www.surpluscenter.com/Hydraulic.htm

Cool! Thanks!


Now knock it off before I get the "build it myself" bug!

 

[slipknot]

This should go down in the a-site hall of fame as one of the best threads!
I was thinking of starting one but don't know enough about hydraulics like blueridgemark! Thank you for starting this...I have been wanting to get to the bottom of this matter! Now I shall learn! opcorn:

 

[monk680]

Here is the cylinder size to pressure calculations
----------2250-----2500-----3000 psi
3"-----------8------8.75------10.59
3.5"-------10.8------12--------14.4
4"---------14-------15.7------18.85
4.5"-------17.89----19.88-----23.85
5"----------22-------24--------29
6"---------31.8-----35.33-----42.40

 

[SmokinDodge]

So I guess we're back to, "Does anybody know how they measure the tonnage?"

F= P x A

Force equals pressures times area. Period. That is the only calculation that is needed for figuring the working tonnage of a cylinder.

I've often wondered how they come up with some of their ratings on the commercial splitters. It seems they are rating them as running the pump at full capacity, 3500 - 4000 psi, but when they are sold most are set to run only 2250 - 3000 psi.

 

[BlueRidgeMark]

F= P x A

Force equals pressures times area. Period. That is the only calculation that is needed for figuring the working tonnage of a cylinder.

Yep. But then...

I've often wondered how they come up with some of their ratings on the commercial splitters. It seems they are rating them as running the pump at full capacity, 3500 - 4000 psi, but when they are sold most are set to run only 2250 - 3000 psi.

I think you may have hit the mark on this. It's sort of like the EPA gas mileage - it might be useful for comparing one against another, but you aren't going to see anything like it in the real world.


These days I'm getting my truck loaded with log ends each morning on the way to work. Fella loads me up with a big knuckle boom that has a claw on the end that can pick up a 40" diameter oak log. The cylinders on that look to be maybe 8" diameter at most. I have to wonder what kind of pressure they run.

You ought to see the hydrauliclly powered saw on this rig - it's got to be a 5 foot bar, and it goes through hardwood like The Predator would go through balsa wood. Throws a rooster tail 20 feet! opcorn:

 

[BlueRidgeMark]

I was thinking of starting one but don't know enough about hydraulics like blueridgemark!

Hey, all I know is the basic formulas, like Smokindodge posted. It's pretty basic at that point.

But I'm glad this is a useful discussion. I'm here to learn, too!

 

[monk680]

F= P x A

Force equals pressures times area. Period. That is the only calculation that is needed for figuring the working tonnage of a cylinder.

I've often wondered how they come up with some of their ratings on the commercial splitters. It seems they are rating them as running the pump at full capacity, 3500 - 4000 psi, but when they are sold most are set to run only 2250 - 3000 psi.

That is what I posted. A 3" cylinder at 2250 makes 8 tons at 2500 it makes 8.75 tons at 3000 it makes 10.59 tons. PERIOD. Sorry for taking the time to do the calculations. No log splitters run at 4000 psi most cylinders are 2500 or 3000 psi and few gear pumps make 4000 psi. The most I have ever seen is 3625psi.

 

[Sparky_NY]

Interesting thread.. I built a log splitter last year and ran into the same questions. A little research made for even more questions! The only 2 stage pumps I could find were halidex/barnes.. those pumps are rated at 3000 psi max and the commercial units seem to all use that type pump. Even giving the splitter manufacturers benefit of a doubt on the pump, saying they found a 2-stage rated at say 4000psi, the horsepower required to run that pump is quite a bit more than what is on the units, magic once again. Another point (previously pointed out) is the supporting components, hoses, valves etc, are not usually rated for 4000 psi pressure. It seems like manufacturers are playing games somewhere.
I ended up with my splitter using 3000 psi (with a gauge to keep track of things) and a 4 inch cylinder. Interestingly, it out performs 30 ton rated splitters without a doubt. (used a friends "30 ton" splitter before I built mine).
Departing from the norm, I used a commercial 5hp electric motor. My splitting is done in front of the garage and the electric is quiet, powerfull, easy on-off, no fueling etc. Size for size, electric motors perform equal to gas units of twice the size.

 

[mga]

sparky...that 5hp electric motor is 220...correct?

 

[cord arrow]

i reckon it would have to be. unless of course ya had more money than you knew what to do with.

then again, in the big scheme of things, you really don't run 'em a whole lot of hours...comparatively, maybe you could go 110.

 

[Canyon Angler]

Sparky NY,

I would like to know more about your splitter.

I bought an old farmhouse (formerly a working farm) and in the barn, there's a big hydraulic ram for a forklift-type thing. The piston must be 5" or 6" diameter, with a throw of probably 4-6 feet.

I'm thinking of trying to get the parts to make it into a log splitter...and I like the idea of electric, since I only burn maybe 3 cords a year.

Can you tell me about yours?

What size/voltage/cost motor?
Cost of other components?
Any pointers on where/how to learn how to make one?

Thanks,

CA

 

[KiwiBro]

W T F?
45t?
http://www.trademe.co.nz/business-f...forestry/forestry/other/auction-829793971.htm

 

[Hddnis]

Holy zombie thread batman! 9 years old!





Mr. HE

 

[Guswhit]

Research? Bored? I'm sure we have all been guilty of opening an old thread.

 

[mn woodcutter]

Research? Bored? I'm sure we have all been guilty of opening an old thread.

I normally prefer to pick up old threads instead of starting new ones about the exact same topic. Maybe we could start another fiskars thread!

 

[mga]

I normally prefer to pick up old threads instead of starting new ones about the exact same topic. Maybe we could start another fiskars thread!

or, how about another how big is a cord of wood thread?