engine & pump size?

[STEADY EDDIE]

Posted in another forum and I was instructed to ask the question in this forum as well. I am building a monster log splitter to quarter up the 48" plus rounds that i have been accumulating. I am trying to do it as cheap as possible. I have acquired a 8" x 72" x 3" piston, a 50 gallon hydraulic tank, and a 20 foot 12" I-beam. I am wondering if I can put a smaller 2 stage pump (22-30 gallon) and I have an 18 hp motor just sittin in my garage. will these work? not worried about speed- just want to do the job. thanks eddie.

 

[LD1]

A 22gpm 2-stage pump like this one https://www.surpluscenter.com/item.asp?item=9-7970&catname=hydraulic flows 7 gpm on the hi-pressure side @ 3000psi.

The formula is (PSI x GPM)/(1714 x % eff)= required HP

So, (3000psi x 7gpm)/(1714 x 85% eff) = 14.4HP required. So YES, the 18hp you have will work.

But, it is going to be REALLY slow. you are looking at 42 seconds to extend in high speed and 36 to retract in high speed. So a 78 scond cycle time:confused2:

On a positive note, with @ 700psi, you can develop almost 18 tons of force without even hitting low speed. But if god-forbid it does shift into high pressure low speed, you are looking at a blistering 30 inches per minute extend speed:laughing: Can you say "how about a cup of coffee while you wait"

And if you ever do need the full power of that beast, it will be in the order of 75-76 TONS of force. And Unless its a super heavy duty 12" beam, I dont think it is up to the task. You are going to need to build the thing like a tank.


All that said, I have two questions for you:

IS the 72" of length actuall required? or is it just what you have?

You should really consider selling that cylinder if the length isnt needed. And getting something more reasonable. I know it sounds cool to build that monstorous of a splitter. But it is going to be inefficent and not real practical IMO.

 

[muddstopper]

I'll just add that I regularly 4way split 36inch rounds using only a 4in bore cylinder. If I read your numbers right you want to use a 8in cyl. thats 4 times the splitting force as my splitter. Overkill to say the least. In order to have any reasonable speed you will need about a 40-50 gpm pump, which your 18hp engine isnt going to pull. Sell the big cyl and find you a 5in'er. The cyl you are describing must of came off a large trackhoe and should bring more than enough money to buy what you really need. Do you really need 72in of stroke?

 

[LD1]

thats 4 times the splitting force as my splitter.

And 4 times slower in terms of inches per minute. Then the cylinder is 3x's longer than a normal splitter.

EQUALS....12 times slower.

 

[STEADY EDDIE]

maybe I should clarify what Im trying to do. I should have said logs and not rounds. I have ten to twelve foot log sections that are 48 inches around. I want to cut them in six foot lengths and them split them down so i can run them through a processor. Thats why I wanna use the long piston and need the power not the speed.

 

[J_J]

Doesn't seem practical,

Why not cut the logs to 24 in and use a 4 x 24 in splitter with this set up.

The tonnage on a 4 in, and 3000 psi should be sufficient .

Dad's Wood Splitter - YouTube

 

[LD1]

Yeah, just dont seem practical. But the short and sweet answer is yes, your motor will work with a 22gpm.

But I think it would be far faster, and much less costly, to cut them down to 16-20" and then split them conventionally. Whatever time savings there will be with the processor, will be lost and then some just getting the "logs" sized so the processor can handle them.

 

[STEADY EDDIE]

I thought I would save a lot of time splitting in larger sections rather than cutting such large logs. Im thinking its easier to cut once manually and then let the equipment process the rest. I had a timberwolf tw-6 that i just sold. all of my wood comes for free but it comes very large and in log form?

 

[LD1]

If that is your goal, I dont think you will reach it with what you are planning.

Now if you had a bigger motor and a ~50gpm pump, then maybe. But given how SLOW it is going to be to split them, and then at only 6' at a time and then the processor STILL needs to cut them, I dont see it being any faster. Not to mention having to handle a HUGE log and get it ONTO the splitter. How were you planning that?? A 6' long 48" diameter peice of green hardwood can weigh in excess of 4500lbs:shocked:

 

[mikehaugen]

Not to mention having to handle a HUGE log and get it ONTO the splitter. How were you planning that?? A 6' long 48" diameter peice of green hardwood can weigh in excess of 4500lbs:shocked:

maybe this would be the time where a FEL (or skidsteer) mounted upside down mounted splitter would be practical. Then you could just use the skidsteer hydraulics?

you may also want to find a bigger i-beam, or another one the same size and double them up.