Trying to design a log splitter

[williamdubois]

Hey guys,
Im new to the site and I was wondering if all of you smart people could hepl me with some stuff. I recieved a prince 4 x 20 3000 psi hydualic cylinder and wanted to know how big does all the other parts, for example, the motor, hydraulic pump, spool valve and holding tank need to be. Im looking to find all of these parts for free by looking online all the time. I did not pay for the cylinder and would like to not pay for anything else. Please help me out. Not sure what to do. Thanks

 

[farmboss45]

Hey guys,
Im new to the site and I was wondering if all of you smart people could hepl me with some stuff. I recieved a prince 4 x 20 3000 psi hydualic cylinder and wanted to know how big does all the other parts, for example, the motor, hydraulic pump, spool valve and holding tank need to be. Im looking to find all of these parts for free by looking online all the time. I did not pay for the cylinder and would like to not pay for anything else. Please help me out. Not sure what to do. Thanks

First of all, Welcome to the site:cool2:!! Try calling Burden surplus center.com, they have a tech on staff named Conrad, can answer all your questions, without trying to upsell everything. Next, put a lot of thought in the design items such as height, location of controls, log lift etc... pricless when you get the right combination of what you need. Check out the woodsplitter pic thread in the firewood and heating forum, lots of pics for ideas. A lot of talented guys on the site

 

[stltreedr]

I wish you very good luck in obtaining these items for free, they are valuable and some are expensive. You have one critical part, which is good, but probably not even the most expensive. You need to decide what you want to do with your machine, and match the parts to that.

Pick your hydraulic pump out, if you want to run 3000psi, you need to make sure your pump will produce that. The flow rate, in GPM, determines how fast the cylinder will cycle, the more psi and GPM, the larger your motor needs to be. There is a formula that calculates HP as a function of PSI and Flow. I don't know it by heart, but you could look it up.

Make sure your valves match the PSI and flow rating of the pump- if the valve is flow restrictive, the higher flow pump will do you no good.

Make sure your tank is large enough to handle the flow rate of your pump, about 1 gallon of tank for every GPM of flow is rule of thumb- but for a splitter you can go a little less. Remember that with a 2 stage pump the low flow side is where the work is done.

Steel is expensive, welding rods, gasses, wire, are expensive, paint and primer is expensive...and HYDRAULIC HOSES AND FITTINGS ARE VERY, VERY EXPENSIVE! These are items that you aren't going to get for free.

The last post in my splitter build contains this phrase, "It aint worth it" Buy a used splitter and save yourself money and aggravation. Unless you are like me, and just like building stuff. But, I've done it once, and don't intend to do it again.

 

[williamdubois]

Thanks for the advice so far. The good thing for me is that I am a metal worker and Im very good at welding, so the metal will more than likely not cost me anything. Also, I have my own welder and my father-in-law works on forklifts so he may be able to get the fluids, pump and hoses at little to no cost. I have looked up several pics of ready built splitters at Northern tool. I love to design things and try to make them better so I may re-design a splitter that I like. What Im trying to do is to make a really powerful splitter as small as possible. It may take awhile but I will try to post pics as soon as possible. Thanks.

 

[farmboss45]

Make sure your tank is large enough to handle the flow rate of your pump, about 1 gallon of tank for every GPM of flow is rule of thumb- but for a splitter you can go a little less. Remember that with a 2 stage pump the low flow side is where the work is done.

Steel is expensive, welding rods, gasses, wire, are expensive, paint and primer is expensive...and HYDRAULIC HOSES AND FITTINGS ARE VERY, VERY EXPENSIVE! These are items that you aren't going to get for free.

The last post in my splitter build contains this phrase, "It aint worth it" Buy a used splitter and save yourself money and aggravation. Unless you are like me, and just like building stuff. But, I've done it once, and don't intend to do it again.[/QUOTE]

The biggest problem with buying is, you can't get a "tailormade" machine if you buy it. They are all one size/style fits all. Build want you want, it will pay off in the years to come, plus, when you get complements, you get to say "Thanks, I built it!"

 

[stltreedr]

I like your attitude, so ive done a little more work for ya. Horsepower = gpmXpsiX.00058. The low side of my my pump is 7 gpm, high side 22. So at 3000 psi youll need between 12 and 13 hp. Horsepower ratings on motors is not real accurate, so check the actual specs on whatever you choose. Dont understimate the size of the beam you need. There are some really good threads in here with formulas to calculate what you need. If Youre running enough hp to run full 3000 psi, you can calculate the tonnage rating of your 4 inch cylinder by calculating the square inches of your 4 inch bore x psi/ 2000. Im not near a calculator but from memory im guessing around 19 tons. I wouldn't be saying all this if i haven't been here very recently. There are some guys here way smarter than me, farmboss and kevin in ohio for instance, who ive relied on heavily in my build. If your lucky, they'll give you some better guidance.

 

[VA-Sawyer]

19 tons is a pretty good guess. For a 4" bore at 3000 psi, I get 18.84955 tons of force. ( using pi out to 16 places )

I also agree with the other suggestions you made as they are pretty much on the money as well.

Rick

 

[Kneejerk Bombas]

IMake sure your valves match the PSI and flow rating of the pump- if the valve is flow restrictive, the higher flow pump will do you no good.

I have a 16 gpm pump, and an 8 gpm valve. Will slow cylinder movement be the only problem?

 

[farmboss45]

I have a 16 gpm pump, and an 8 gpm valve. Will slow cylinder movement be the only problem?

You may be in danger of blowing seals out of your valve, or blow by in the spool. Your valve should meet or excede your pump rating.

 

[Kneejerk Bombas]

You may be in danger of blowing seals out of your valve, or blow by in the spool. Your valve should meet or excede your pump rating.

Thanks. The other valve I have is a 24 gpm, is that too much?

 

[farmboss45]

Thanks. The other valve I have is a 24 gpm, is that too much?

As long as your valve is at or above the rating of your pump, your good. It does not matter how much bigger, it just can not be the other way around. I run a 22gpm pump with a 24 gpm valve. Not sure why its hard to find evenly matched components.

 

[Kneejerk Bombas]

Here's a head scratcher, what if I have the 24 gpm valve with power beyond, then the small valve at the end? Will the flow be divided up in a way that will allow the smaller valve to work properly because it's downstream?

 

[farmboss45]

Here's a head scratcher, what if I have the 24 gpm valve with power beyond, then the small valve at the end? Will the flow be divided up in a way that will allow the smaller valve to work properly because it's downstream?

Good question????? Not sure with that one, I have no experience with the power beyond. You might pm Kevin from Ohio, I believe he uses that option, he built the baddest splitter I have ever seen.

 

[Kneejerk Bombas]

I got it figured out. It doesn't matter because power beyond just diverts 100% of the flow past the valve so the next valve gets the full flow.

 

[williamdubois]

Does my engine have to match my pump and valve. For example, if I found a riding lawn mower engine, which are usually 25 hp, will that be to big to use on a 11 gpm pump with the same size valve.

 

[farmboss45]

Does my engine have to match my pump and valve. For example, if I found a riding lawn mower engine, which are usually 25 hp, will that be to big to use on a 11 gpm pump with the same size valve.

No, I run a 15.5 horse off a riding lawn tractor with a 22 gpm. The horse power does not make much difference, the pump relies on mostly rpm's for the gpm. You could use an 8 horse, 25 horse or bigger. Will not make the pump, pump more.

 

[williamdubois]

The more horse power the better..right..I was using a smaller splitter and when I would get into a harder log the motor would cut off. Could I get away with using a lawn mower engine, say 6.5 hp or is it really nessasary to go bigger.

 

[triptester]

Pumps have a minimum horse power requirement to attain maximum rated pressure.

For 2-stage pumps minimum hp.

11 gpm -5.5 hp
13 gpm -6.5 hp.
16 gpm -8 hp.
22 gpm -11 hp.
28 gpm - 14 hp.

Healthy engines at the peak of their power curve.

 

[williamdubois]

Wow, really good info guys. You guys have helped out a great deal. If there is anything else I need to know, please tell me. Im still looking for all the rest of the parts at the right price, "free", but I still have not come across them. I know they will be there, just need to find them. Thanks again.