New and yup, ANOTHER log splitter project

[Wineslob]

Hi all. I "stumbled" across these forums while searching for "how to build a log splitter"
I've been a maintenance man/plant engineer/stupidvisor in a coating manufacturing plant for over 20 years. I do everything from, fix tha chit to design and build what we cant find, don't have, ect. So I can weld, machine, and figure out how to make it work.

On to the log splitter. I've trolled here for roughly 2 weeks getting as much info as possible. I've got all the parts to start construction of this project.

1. I'm on a very restricted budget.

2. WAF of monies spent on this is very low, see #1

3. I went with the 18" "log splitter" cylinder from here: https://www.surpluscenter.com/item.asp?UID=2009083113122534&item=9-7178&catname=hydraulic, 11gpm 2500 psi 2 stage pump, and the "log splitter" control valve.
4. My wood burning stove is designed for 16" firewood (max, trust me), so I'll never be splitting anything longer. Most rounds I get are 18" and smaller in dia. Thats why the 18" cyl, plus at $40 it works with #1 & 2. I've got it at the house and the quality is pretty darn good for the money. So no worries about it being crap.
5. Most of the wood around here is pine, walnut (orchards), oak, or almond (orchards again). Nothing really 'hairy" to try and split.

Now I've got a "bug" up my butt. I'm just throwing this out there. Could I run 2 of these cyl in tandem? Say, one one top of the other? Would this double the tonnage? (my best guess would be 16 T)
At a cost of 40 bucks for one more cyl, it's doable (see #1 & 2) and I like to think up stuff like this .

Thoughts?

 

[J_J]

Sure could, splitting will be slower with two cylinders. The 11 GPM will be divided equally between the two cyl. Pressure will be 650 psi in the fast made, and 2500 psi in the slow/power mode. Join the two ports, with a tee fitting, one hose from the valve to the tee for each end. You did not say anything about a log splitting valve.

Two cylinders would act like a 6 in cyl with a 3 in rod. force would be 70,686 lbs, or 36.8 ton using 2500 psi in the slow mode . 12 sec extend, 9 sec to retract, with the toughest wood, a shorter time with pine.


ERROR, ERROR, DARN IT.

 

[Wineslob]

JJ thanks. Wow the tonnage is crazy. Much more than I thought it would be.
The valve is this one: https://www.surpluscenter.com/item.asp?UID=2009083114041629&item=9-7724&catname=hydraulic if thats what you are asking?

I may have to re-think the double cyl, I only have access to 6" I beam, I don't think it could take the stress.

 

[J_J]

At 2500 psi

3 in cyl---------8.8 ton
4 in cyl---------15.7 ton
5 in cyl---------24 ton
6 in cyl---------35 ton

 

[rus_geek]

Sorry to correct you JJ, but two three inch cylinders don't make a six inch

Area of a six inch cylinder would be about 28 square inches, where two three inch cylinders would only have about 14. You'd need *four* three inch cylinders to get that tonnage.

-rus-

 

[Grand_Pooba]

Sure could, splitting will be slower with two cylinders. The 11 GPM will be divided equally between the two cyl. Pressure will be 650 psi in the fast made, and 2500 psi in the slow/power mode. Join the two ports, with a tee fitting, one hose from the valve to the tee for each end. You did not say anything about a log splitting valve.

Two cylinders would act like a 6 in cyl with a 3 in rod. force would be 70,686 lbs, or 36.8 ton using 2500 psi in the slow mode . 12 sec extend, 9 sec to retract, with the toughest wood, a shorter time with pine.

JJ I learn something interesting every time I read one of your Hydraulic posts....but I've jump in on your calcs. (2) 3" bore cylinders would give you an piston area of 14.14 sq in. A 6" cylinder would be 28.27 sq in.
Force for (2) 3" cylindeers at 2500 psi would be 35,350 lbs.
Doubling the dia. increases the area by a factor of about 4.

Thanks
Steve

 

[Grand_Pooba]

Sorry JJ not ganging up here. Rus and I must have been typing at the same time.

 

[J_J]

Sorry JJ not ganging up here. Rus and I must have been typing at the same time.

That's Ok, I am old and tired, and I am looking at a lot of numbers on my scratch pad. Two 3 in cylinders would equal a little more tonnage than a 4 in cyl.

I put the correct numbers up above.

 

[Wineslob]

Thanks for the corrections guys. Looks like I just might give it a try.

 

[bassgrinder]

The way you would calculate how much force you would get with multiple cylinders is to multiply the force each cylinder has times the # cylinders However you also have to consider that when you mount them if they cock the slide and make it bind you will lose some or all of that. I have seen one built with 2 cylinders side by side and it would sometimes bind so bad it would stop itself halfway with no block. From what you describe the wood you will mostly split, you may get by with one cylinder for about 12 tons, if you put the wedge on the ram then you can have the ram retract power get any block that gets stuck on the wedge back off, which is by far the worse case scenario when you are under powered.
Going by your first post your best bet may be to use the one cylinder, make it as cheap as possible and be happy with whatever it will do with 12 tons. Just go into it understanding that you are building a 12 ton splitter, with splitters the tonnage is a general yard stick, the higher the tonnage the more it is going to cost to buy or build, period. The only way to cheat that is to find high tonnage parts for sale at a low tonnage price.
I have seen 12 ton units do a nice job on wood like you have described, the problem would come if you tried to compare your unit with a 35 ton unit. Point is, if your gonna need a 35 ton unit, then wait until you can find a 4” cylinder and such that you can afford (Ebay, Craig’s list, local auctions etc). But if you can truly make do with, and want a 12 tonner then go with what you have and build it simple, and fast.

 

[bassgrinder]

The way you would calculate how much force you would get with multiple cylinders is to multiply the force each cylinder has times the # cylinders However you also have to consider that when you mount them if they cock the slide and make it bind you will lose some or all of that. I have seen one built with 2 cylinders side by side and it would sometimes bind so bad it would stop itself halfway with no block. From what you describe the wood you will mostly split, you may get by with one cylinder for about 12 tons, if you put the wedge on the ram then you can have the ram retract power get any block that gets stuck on the wedge back off, which is by far the worse case scenario when you are under powered.
Going by your first post your best bet may be to use the one cylinder, make it as cheap as possible and be happy with whatever it will do with 12 tons. Just go into it understanding that you are building a 12 ton splitter, with splitters the tonnage is a general yard stick, the higher the tonnage the more it is going to cost to buy or build, period. The only way to cheat that is to find high tonnage parts for sale at a low tonnage price.
I have seen 12 ton units do a nice job on wood like you have described, the problem would come if you tried to compare your unit with a 35 ton unit. Point is, if your gonna need a 35 ton unit, then wait until you can find a 4 cylinder and such that you can afford (Ebay, Craig痴 list, local auctions etc). But if you can truly make do with, and want a 12 tonner then go with what you have and build it simple, and fast.

 

[bobodu]

That's Ok, I am old and tired,

Take heart....you look a lot better than I do!!!
At least you got hair.....

 

[Sunkistdds]

I am in the process of building a 2 cylinder, guillotine style splitter to split standing pieces. I have 2 4" cylinders and am using the sides off an old in floor garage hoist for the frame. The only problem I see is a bottom/floor piece that is strong enough with out having to elevate the wood to sit on it. I am thinking 1" flat with a back lip for extra strength. It always seem strange to have horizontal splitters that we either struggle to put the sticks up on, or contrive some hoise system. This to me is the best method of using 2 like cylinders... parallel.

 

[sizzami]

how do you get 35 ton w/ 4" cylinder?

 

[Wineslob]

]how do you get 35 ton w/ 4" cylinder[/B]?

Get a Troy-Built.


Thanks again for all the ideas.
I still might try this, because 40 bucks for another cyl is no big deal cost-wise. I figure they'll be one on top of the other and bolted to a 1" rear plate with a 1" pusher plate. It might cock to the top or bottom, maybe, I'll try to keep the rods as close to center as possible. If it does, I'll just remove and modify back to one, or make a longer slide for the pusher. I'll see what happens.
Speed is not much of a concern, I only split roughly 2 cords a year. Besides, splitting 2 cords keeps me busy for a weekend, and out of the wife's hair.

 

[J_J]

how do you get 35 ton w/ 4" cylinder?

15 ton is all you are going to get at 2500 psi, and that is with the log splitter in the slow mode. High pressure, low GPM.

You have to go to a 5 in to get 49,087 lbs, = 24.54 tons

 

[turnkey4099]

15 ton is all you are going to get at 2500 psi, and that is with the log splitter in the slow mode. High pressure, low GPM.

You have to go to a 5 in to get 49,087 lbs, = 24.54 tons

Yep. 15 is about all a 4" will do. Why the builders get away with claiming 20 ton for a 4" and 27 ton for 4 1/2" I don't know. Simple math says they are way off base. Even with the valve bypass set for 3,000 pounds (not recommended) they don't reach those nubmers.

Harry K

 

[turnkey4099]

<snip>

It always seem strange to have horizontal splitters that we either struggle to put the sticks up on, or contrive some hoise system.

<snip>

I, on the other hand, cannot see crawlign around on my knees trying to maneuver a heavy round on the ground. I have to get whatever I am splitting on the truck to haul it home anyhow so getting it on the splitter is not that big a deal. No deal at all if I split direct from the truck. My old homebuilt was too low and it only took a few minutes for the back ache to begin. I raised it 9" and it became a whole better world. Just the thought of working rounds 'on the ground' brings back memories of back pain.

Harry K

 

[sizzami]

I think the exagerated ratings have led us to believe we need a bigger splitter than we do I have built a PILE of 15 ton splitters and you just dont find rounds under 20 inches long that they wont push through a single sharp wedge.

 

[Sunkistdds]

I, on the other hand, cannot see crawlign around on my knees trying to maneuver a heavy round on the ground. I have to get whatever I am splitting on the truck to haul it home anyhow so getting it on the splitter is not that big a deal. No deal at all if I split direct from the truck. My old homebuilt was too low and it only took a few minutes for the back ache to begin. I raised it 9" and it became a whole better world. Just the thought of working rounds 'on the ground' brings back memories of back pain.

Harry K

I'd agree if ur hauling, but my plan is to put it on a 3 point and just back up to the piece to split. I split some 24" stuff, post oak, and I have been rolling them into a bucket and dropping them in mass into a dump trailer til now. All that size are split the next year ( seasoned) at the pile. I'd disagree on the effort. Flipping a nice sized piece of oak on end is not the same as hoisting it onto a horizontal beam... not even close.

I have been building fires in a central wood heat source since I was a kid 40 years ago, and I just like to use wood now as a backup source until we get to freezing, or even say 40. Nothing warmer on a cold day than wood heat.

I have made 6 pick up bed trailers that I keep full beside the two furnaces. But to each his or her own. What ever works, but I am not into DCs that much.