# logsplitter question



## foxhunter (Nov 1, 2008)

i'm thinking of building my own log splitter. i have everthing except the rail and the hoses. my question is this, can i use the two 3.5"x24" cylinders mounted side by side. i have a 30 gpm pump and valve to match. if so what ton-age will the splitter be. i also want to weld a piece of metal sarated floor plating (the diamond shaped non skid type) to the front of the ram to keep the log from slipping under pressure. 

any thoughts?

tia 
bob


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## eernest4 (Nov 1, 2008)

foxhunter said:
			
		

> i'm thinking of building my own log splitter. i have everthing except the rail and the hoses. my question is this, can i use the two 3.5"x24" cylinders mounted side by side. i have a 30 gpm pump and valve to match. if so what ton-age will the splitter be. i also want to weld a piece of metal sarated floor plating (the diamond shaped non skid type) to the front of the ram to keep the log from slipping under pressure.
> 
> any thoughts?
> 
> ...



First, the proper place for this post is in the GEAR ROOM, remember that for next time.


For the rail you can cut up a - I beam - from the scrape yard with a oxygen-acetlyne cutting tourch & weld on a wedge on the end of the beam or just a foot plate on the end of the I beam
& put the wedge on the ram of the cylinder. That way, you can place a scrapper plate that the wedge will retract past & it will scrape off any rounds stuck on the wedge.

Also, you will need the foot plate on the end of the I beam if you are planning a verticle/ horizontal log splitter.

Do Yourself A Favor And PLan for a VERTICLE MODE LOG SPLITTER so you dont have to lift all that heavy wood up to a horizontal table. Your back & other assorted muscles, not to mention your hernia,--will thank you for it. 

With less opperator fatigue, you can get more wood split.

Also ,look into www.northerntools.com 
 they sell a  4 way wedge , and it quarters the round with one stroke instead of just halfing the round as most log splitters do. Less strokes & miller time is sooner!


Several thoughts. Tonnage should be 30 to 40 tons but with parallel hydralic cylinders you
might or might not have a hydralic flow rate problem.

What if one cylinder goes faster than the other cylinder. Will this cock the ram off to one side & cause it to jam the ram guide or bend your metal??

With a 30 gpm hydralic pump, what hp of gasoline motor are you planning to use a 20 hp honda vortec twin  ?  Or maybe just a small 12 hp & strain the heck out of it??

If I were doing it, I would only use 1 hydralic cylinder for about 22 tons (20 to 26 tons depending on the cylinder) & not have  to worry about unequal cylinder speeds.

You would do well to find out from someone that knows more about the subject than me because I never considered dual cylinders before, I would just buy a stronger cylinder instead.
so as to "keep it simple,stupid", like prez clinton used to say.

The 4 way wedge needs 28 ton to work well because it is hitting the round with 4 edges 
(+, _ ) instead of one edge.

Unelse you are planning on building a commercial log splitter (it can split anything no mater how knotty or knarley the wood may be) you are planning for massive overkill & unneccessary expense
both in parts & in gasoline consumption with the larger engine.

Weight may be another factor, especially if you have to move the splitter when it is not hooked up to the tow hitch.

If you are building it yourself,& plan on towing the log splitter, use a solid, all the way across, axil with highway speed tires, fenders & license plate & turn signals, so you can easily tow it. 

The small 8 inch tires are only good for 50 mph,
maximum & the axil stubs that are welded on to the log splitter's hydralic tank can rip the hydralic tank open if you hit a pot hole or rail road tracks. Mine don't have fenders or lights or wiring ,either. Most don't because of keeping the cost competitive. So a  log splitter made to really tow at highway speeds, costs extra.

The cheaper homeowner type of log splitter is not made to tow much, if at all. But the huskee 22 ton sure splits wood great


The engine size is primarly determined by the pump size, the more gpm the more hp needed.

For a normal 20 -26 ton log splitter, a 10 to 12 gpm & a 6.5 hp to 8 hp engine are fine & less
expensive gasoline wise to opperate.

Special thought should be given to the routing of the engine exhaust well away from the opperator, no mater which way the wind is blowing from. 

this is something that the homeowner models give no thought to in the least. 

Most times, you get the exhaust right in your face & then you move the log splitter, only to have the wind shift & the exhaust is right back in your face again.

Who wants to spend most of the day repositioning the log splitter every time the wind shifts.

A shady area is a must to a comfortable day of log splitting. I ended up with electric lights & splitting at night due to lack of shade. Its a lot cooler at night too, so you dont work up a sweat.

I have a 22 ton huskee that I buy from www.tractorsupply.com for $1150.oo fully assembled & including engine & hydralic oil & I have not yet hit a log or knot or limb in the trunk that
it won't split through ,although sometimes I have to go to full throttle, momentarrily, to do it.

For most logs, & for most of the splitting session, the 22 ton huskee with 6.5 hp B&S;engine opperates at just over idle speed.

There are web sites that will sell you a how to build your own log splitter book for $12.95+ship&handling;, so you should check that out before buying the parts & learn how to match the parts to the intended outcome.

www.ask.com or www.google.com

Why go 30 to 40 tons when 22 tons is all you need, unelse you want a commercial grade log splitter for a business & then you should get one with a hydralic log feeder /lifter arm or table
to bring the rounds up to the horizontal bed.
My splitter is opperated exclussivley in vertical mode, even though I have horizontal mode available to me . I never lift a round up off the ground in vertical mode & I love it.
Horizontal mode sucks hard, with all that lifting, compaired to vertical mode.
Opperator fatigue is important on a long day of splitting.
You can Personal Message me if there are any questions.
I was planning to build my log splitter, but I needed to spend my limited time splitting wood for winter.


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## eernest4 (Nov 1, 2008)

After thoughts

www.craigslist.com 

                    Sometimes they have a rusty log splitter frame for sale for around $100.oo

                   No engine, pump or ram just the I beam & wedge & prehaps a trailer frame 
with wheels & flat, bald or dry rotted tires.

                  But, this could save you money if you dont already have welding equipment
& the trailer frame parts, axil, wheels, bearings, fenders, hitch.

                   If you plan on towing, repack the wheel bearings, first, because otherwise you won't be able to go far before a wheel falls off.  You may need to replace the bearings & races & rear grease seal if they show wear or looseness.

A trailer wheel hub grease fitting cap is a good idea ,too. That saves you from doing yearly wheel bearing regreasing.

                   There are instructions on how to do that here on hearth.com in the fix it up how to do it yourself room.


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## WES999 (Nov 1, 2008)

I think mounting 2 cylinders side by side is asking for trouble, I think they would be prone to cocking.
Your question regarding tonnage can't be answered unless you know the pressure you will be running.
Check out this website : http://www.baumhydraulics.com/pages.php?pageid=4
They have several hydraulic calculators to help determine cylinder force and speed. 
If you run your pump at 3000 psi with a 3.5 dia cylinder you will have about 15 T.
I rented a 16 T splitter and split every thing I had with no problem.


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## fabguy01 (Nov 1, 2008)

you CAN use two cylinders but you MUST use a flow divider to keep the cylinders at equal stroke. most hydro shops approx 150$. second your tonnage use    pie x the radius of cylinder bore squared  take that number x the line pressure.    p.s. pie=3.14                                                               Nate


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## foxhunter (Nov 6, 2008)

thanks guys, all the parts except the ibeam and wedge have been given to me , so i could be into it right. thought about mounting the cylinders one on top of the other rather than side bu side. like the idea of the scraper plate and i don't think i will make it portable. i'll check into what it takes to equilize the two cylinders or maybe i will just use one and always have a spare.
i have a gresen control valve and a 5 gallon fluid tank.
thanks again.


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## Gooserider (Nov 6, 2008)

A 30gpm pump with a 3.5" cylinder, or even two will give you a really fast cycle time, possibly dangerously so, be careful.  

You will also need to figure out the specs on the pump, is it two stage or single stage?  If it's single stage you may need some additional plumbing to get the appropriate high pressure modes.  If it's a two stage pump, you will need about a 15hp motor to drive it, or possibly something much bigger if it's a single stage...

Look closely at the hose sizes you will need, a high gpm pump requires much larger diameter hoses than usual to avoid friction heating.  (And that tank size sounds a bit on the small size as well)

Sounds like you have the makings of an interesting contraption, and obviously having free stuff to use is a strong consideration, but I'd make sure to go through some of the hydraulic design sites and really nail down the specs on everything - it's entirely possible that you might find it less expensive to toss some or all of what you have and buy more "standard" parts than it would be to get the things you need to make what you have work...

Gooserider


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## Dill (Nov 6, 2008)

I'd just run one clyinder for convinence if nothing else.
If the wedge is not on the ram, I haven't had an issue with wood slipping when its being pushed.  And make sure you make it up to that you can't over stroke the system, in case someone isn't paying attention you don't want the ram and wedge to hit.


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## Jags (Nov 6, 2008)

If that 30 GPM pump is a single stage, your gonna have to bolt it to some pretty good HP to create any kind of pressure.


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## Dune (Nov 6, 2008)

A few  issues in my mind. Two pistons could work, but defintely goes againt the k.i.s.s. principle. 30 gallons/min is a BIG pump for a log splitter. Figure one horsepower per gallon of flow at 1500 p.s.i. So, you may need a 30 hp engine for that pump, although there may be a way to use that pump with a smaller motor. It dependes upon the pump type and the r.p.m. curve. You really need the pump specs to select the proper motor and gear reduction or direct drive.  Yes you could weld a piece of expanded metal on the end of the pusher. And lastly, there is a specialy made valve just for use on log splitters. It is highly recomended that you use this specific valve.


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## jdemaris (Nov 6, 2008)

foxhunter said:
			
		

> i'm thinking of building my own log splitter. i have everthing except the rail and the hoses. my question is this, can i use the two 3.5"x24" cylinders mounted side by side. i have a 30 gpm pump and valve to match. if so what ton-age will the splitter be. i also want to weld a piece of metal sarated floor plating (the diamond shaped non skid type) to the front of the ram to keep the log from slipping under pressure.
> 
> any thoughts?
> 
> ...



Using two small cylinder instead of one big one is asking for design problems.   If you want a splitter that can virtually split anything with 2000 PSI, you need a 5" bore cylinder - which has an effective area of 19.6 square inches.  Your dual 3 1/2 " cylinder comes out almost the same - at 19.2 square inches.

As to your 30 GPM pump, rated 30 GPM at what speed?  A GPM figure means nothing without RPM.  Any gear pump makes more depending on how fast it is run, and takes more power with more RPM and pressure.

An 8 horse gas or diesel motor hooked to a commonly found 23 GPM at 2000 RPM gear pump (like many backhoes and tractors use) - coupled to a 4" bore cylinder - even with a 1 to 4, engine to pump speed ratio, it will stall the engine with a hard piece of wood. With that gear-down ratio, that 23 GPM pump becomes a 10 GPM pump and it's still too big for an 8 horse engine running at 3600 RPM. It won't work, thus the need for a two-stage pump. If you direct-coupled that 30 gallon pump to the engine, it wouldn't split anything. Now, a two-stage pump shifts to "low gear" with slow speed high pressure so a small engine can handle it during the high PSI needed to split hard wood.  Then, it can shift to "high gear" with more flow, less PSI to your machine can cycle faster.

My John Deere crawler is 36 horsepower and is direct coupled to a 23 GPM pump (rated at 2000 RPM).  When hooked to a 4" cylinder, it just barely has the power needed to split large hard maple unless I run the engine at full speed.   I also have a three-point hitch splitter with a single stage PTO pump that runs off the tractor.  It has a 4 1/2" cylinder and my Case 28 horse tractor runs it OK.

Here are some specs if you want to think a bit.

A large PTO, single stage pump specs like this: 

At 500 PSI, it pumps 21 GPM and needs 8 horsepower to run.
At 1000 PSI, it pumps 21 GPM and needs 16 horsepower to run.
At 2000 PSI, it pumps 21 GPM and needs 32 horsepower to run.

You want 2000 PSI, at least, for a log splitter with a minimum of a 3 1/2" cylinder bore - but 5" is much better.


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