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.

 

[muddstopper]

I understand a little better what you are trying to do now. The logs you are getting wont fit into the processor so you want to split the logs so they will fit. I have seen homemade fence post splitters. they usually have larger diesel engines and pumps off of salvage equipment. Even tho you say speed isnt important, I think you will get pretty tired of waiting on those big logs to split with what you are proposeing. Time is money too!. My opinion is look for a piece of scrap equipment, rob the engine and pumps, and control valve, and build something to get the job done without taking all day. What are you planning on using to load those logs in the splitter and or processor. You might be able to just tap into the hydraulics and not need to worry about buying a pump and motor.

 

[STEADY EDDIE]

Thanks mudstopper for understanding my thoughts. I figure I can run the processor while I have another guy running the splitter. I get the wood for free all day long but often its in 28" to 48" diameter. Instead of spending $150,000 dollars on a huge processor I can quarter these pieces down and run them through a 20" processor. Everyone is concerned about speed but im not. I just wanna be able to process the logs and im trying to do it cheaply. So far everything Ive gotten for the build has cost me 100 bucks. I have my eye on a piece of 12" I-beam 3/4 inch thick. Then all I have to do is weld it all together. Ive seen another guy in the area do the same thing however he purchased his "monster splitter" from a commercial manufacturer and paid $60,000.00 Thats a lot for just gaining a minute or two timewise. As I said just want to make sure it will work before I build it not concerned about speed. I understand your idea about finding scrap motors and such but Im trying to use what I already have. thanks

 

[LD1]

Yes it will work. But like I said, you have to build it SUPER STRONG, as that thing is capable of ALOT of tonnage.

And I dont think you ever answered, but HOW are you going to wrestle 4500lb peices of wood onto that thing?

 

[muddstopper]

I dont know just how strong that thing needs to be to do what he is trying to do. In fact, unless he has some super nasty knotty stuff, I bet the logs will split using about the same amount of power needed to split a normal sized round. Yes, with a 8in bore cylinder he will have tremendous capapcity, but I doubt he will ever use all of it. I regularly split 30in rounds, full of knots, using a 4in bore cyl. I always split these size rounds with a 4way wedge and my splitter never even starts to bogg. I suspect that longer pieces will be as easy to split as the shorter stuff, they will just be harder to handle. I also think that once he has it built, he will start trying to figure out a way to speed it up.

 

[J_J]

STEADY EDDIE ,

Most hyd pumps will develop the pressure you need for force as long as you have the HP.

The displacement and rpm will determine the GPM.

The trick is to match up pump, cyl and engine.

The more GPMs, the faster the cyl will move.

A small cyl will be faster than the 8 in cyl for sure.

An 8 in cyl with a 3 in shaft, and 3000 psi will develop about 75 ton.