iDRY Vacuum Kilns

Sponsors:

Log splitter force question.

Started by Modat22, November 09, 2007, 10:34:03 AM

Previous topic - Next topic

0 Members and 1 Guest are viewing this topic.

Modat22

I've got a few parts laying about and thought about making a super duper log splitter.

After doing some calculations a few things don't make since to me.

My current log splitter is rated at 25 tons, has a 9hp gas motor, 2500 psi 2 stage pump and a 5 inch cylinder. Math says

F=PxA thus 2500psi * 2.5squared = 15625 pounds of force. 2000 pounds = 1 ton

so my 25 ton splitter can actually only generate 7.8125 tons of force. How the heck are they getting 25 tons of splitting power?

The splitter I want to build will be a 16hp gas motor, coupled to a single stage 4000 psi gear pump and a 6" dia cylinder and an adjustable flow rate valve (to adjust cylinder cycle speed)

The force I think I'll get will be f=pxa or 4000*3"squared=36000 pounds which is 18 tons over twice the force of my store bought splitter.


Anyway my original question is how do the store bought machine get 25 tons from a 7.8 actual ton machine? Are my equations wrong?
remember man that thy are dust.

beenthere

What can't you split with the rig you have now? That is the bottom line when I think on what my splitter will do ( 8hp with 4" cyl, and it splits the white oak, red oak, and elm easily).  ??? ???

I haven't the slightest idea what the "advertised" tons are for this rig, and don't really care.. ;D
Sorry, doesn't answer your question.  ::) ::)
south central Wisconsin
It may be that my sole purpose in life is simply to serve as a warning to others

Modat22

I want faster cycling times on the cylinder and faster splitting. I also want to use the homemade splitter as a hydraulic power pack for a log loader on my mill.

It would also be kind of nice to have two splitter running when I'm cutting firewood, we go out with 3 other families and could easily keep two splitters running at full bore.
remember man that thy are dust.

pineywoods

You forgot the constant pi when figuring the area. comes up to about 22 tons, still shy of the advertised 25 tons. Advertising  ::)
1995 Wood Mizer LT 40, Liquid cooled kawasaki,homebuilt hydraulics. Homebuilt solar dry kiln.  Woodmaster 718 planner, Kubota M4700 with homemade forks and winch, stihl  028, 029, Ms390
100k bd ft club.Charter member of The Grumpy old Men

Modat22

remember man that thy are dust.

rebocardo

> How the heck are they getting 25 tons of splitting power?

Maybe by the amount of force applied to the narrow sliver of the wedge's leading edge?

Modat22

after putting pi where its supposed to be it works out
store bought splitter = 24.5 tons

DIY splitter should be 56.5 tons of splitting power

Can't believe I left out pi  ???
remember man that thy are dust.

beenthere

If you want faster cycle times, don't go to the 6" cyl. Unless you have a way to up the gpm from the pump. Have you figured that number yet?
I once helped split around a homemade splitter, with a 6cyl engine, 6" garbage truck cyl and pump. The cylinder moved at a snails pace..it had awsome power...enough to blow the welds and bend the steel in the beams and the wedge steel.  Lots to consider.

Still wondering what you might want to split that your present splitter won't handle. Just curious.  :)
south central Wisconsin
It may be that my sole purpose in life is simply to serve as a warning to others

Tom

I have a "commercial" built homeowner splitter with a 20 ton tag and Live Oak, Sweet Gum, Black Gum and the knots of plantation Pecan will make it whimper.   I've even stalled it in Live Oak when I took too big of a bite.  :)

I don't go for the middle of a big log.  I usually trim from the outside in.  They come apart easier. :)

Larry

Your gonna need lot more than 16 HP to pump the gpm's you will need with a 6" cylinder...unless you want to take a nap while it cycles.
Larry, making useful and beautiful things out of the most environmental friendly material on the planet.

We need to insure our customers understand the importance of our craft.

Modat22

I have a 28 gpm pump. its probably to much GPM for my 16hp motor. I guess I could hook it up to a ford escort motor in the bone yard.

Let me look up cycle times for that 6 inch cylinder based on gpm.


"Still wondering what you might want to split that your present splitter won't handle. Just curious. " I don't need 56 tons of splitting power honestly, but a hydraulic power pack this size will be handy for powering other things. I might as well build for adaptability.
remember man that thy are dust.

raycon

I have a 6" cylinder on my homemade splitter. I use a pretty blunt wedge. Cycle time is about 15 seconds.  I did not know my pumps GPM when I put it together just hodged podged it.

231 in^3 per gallon

Cylinder Volume (in^3) = pi*3^2* stroke = 3.14*9*24  or 680in^3 or 3 gallons

Full cycle in/out = 6 gallons you're looking at (6/28)*60 or about 13 seconds. 

When splitting unless its a entangle grained wood like elm it  probably travels less than 12inches. Engine I'm using is an old Tecumsech cast iron off a Wheel horse I'd guess its 12hp maybe more. Next task is to rig lights to run off the generator/alternator it has to split after sunset.



Lot of stuff..

Fla._Deadheader


There's no load on the return stroke. Use a BIG hose on the return. I used 1/2 or 5/8 on the two I built, 40+ years ago.

  First had a 40" double shaft 4" cylinder from an Asplundh Bucket truck. Split Stave bolts with it among other things. Had a Onan 2 cylinder I bought for $25.00, and a hyd pump from an Elgin Street Sweeper. Wife ran it and I stacked-threw into ranks, after dark. Used old street light heads with adapter sockets and 12V bulbs and ran off the camper battery in our pickup.

  Second had a 8" Cat loader bucket dump cylinder. It had a 5 HP Briggs and another Elgin Street Sweeper pump. Both used 3/8 " pressure hose.

  Both would wear out 2 people per tank of gas. Didn't need no 2 stage pump, just trial and error for a short while. Taught me enough about hydraulics to proceed down lifes path a little easier using hydraulics.  ;) ;D :D
All truth passes through three stages:
   First, it is ridiculed;
   Second, it is violently opposed; and
   Third, it is accepted as self-evident.

-- Arthur Schopenhauer (1788-1860)

scgargoyle

I've been looking at splitters lately, and every single one of them is actually less than the advertised tonnage- how can they do that? BTW, on a big splitter, you'll want to go 3/4" hoses to get the full advantage of a bigger pump, speed-wise.
I hope my ship comes in before the dock rots!

woodmills1

yes circular area is pi times radius to the second power

and cycle time is based on pump flow and piston area

in general the bigger the piston the more flow needed to salvage cycle time

O heck its not pie are squared its cake are squared pie are round :o ;D ;D :D
James Mills,Lovely wife,collect old tools,vacuuming fool,36 bdft/hr,oak paper cutter,ebonic yooper rapper nauga seller, Blue Ox? its not fast, 2 cat family, LT70,edger, 375 bd ft/hr, we like Bob,free heat,no oil 12 years,big splitter, baked stuffed lobster, still cuttin the logs dere IAM

Raider Bill

Quote from: scgargoyle on November 09, 2007, 03:57:06 PM
I've been looking at splitters lately, and every single one of them is actually less than the advertised tonnage- how can they do that? BTW, on a big splitter, you'll want to go 3/4" hoses to get the full advantage of a bigger pump, speed-wise.
John,
When you get your new splitter can I borrow it?
The First 70 years of childhood is always the hardest.

solodan

I just bought a new splitter, I was tired of fixn the old homebuilt one, and that old Tecumseh finally quit working . Plus I wanted one that worked in vertical position. I was looking at the cycle times of different models and it seems most were around 13 to 16 seconds, but I didn't really care what the cycle time was when I realized they were so close. Most of what I split pops apart with a few inches of travel. ??? So what is the difference in cycle times when the ram is only traveling a few inches?  Not much. check out the cycle times on Super Split.  Way faster than hydraulics. :)

beenthere

solodan
Are ya sayin you bought the Super Split then? 
south central Wisconsin
It may be that my sole purpose in life is simply to serve as a warning to others

scgargoyle

Quote from: Raider Bill on November 10, 2007, 09:50:57 AM
Quote from: scgargoyle on November 09, 2007, 03:57:06 PM
I've been looking at splitters lately, and every single one of them is actually less than the advertised tonnage- how can they do that? BTW, on a big splitter, you'll want to go 3/4" hoses to get the full advantage of a bigger pump, speed-wise.
John,
When you get your new splitter can I borrow it?
Sure, but it's not gonna be until I move to SC- still a couple years away, I have a friend who just built real close to our property, and we're thinking about going in together on a splitter, since it only gets used once a year.
I hope my ship comes in before the dock rots!

Warbird

You guys can borrow mine, if'n ya like.  ;D

Ironwood

Couple friends have Super Splits, AWSOME, Pricey but awsome. For those not familiar they run on a momentum wheel and gear rack. Really nice design and worth the money if your spliting lots.

                       Ironwood
There is no scarcity of opportunity to make a living at what you love to do, there is only scarcity of resolve to make it happen.- Wayne Dyer

solodan

No,  I did not buy a SuperSplit. :) The only SuperSplits I saw were horizontal only. :-\ I bought the 30-ton from Northern. I still have not seen it in over 2 weeks.  :'( It should be here Monday. :) I'll let you guys know. It only has a 5.5 HP Honda, which seemed small to me but I have been told that the newer small motors have plenty of power to run the pumps on a splitter.  It is the GX engine I believe, which is the commercial grade engine. Like I said before almost everything I split only requires me to push the ram in a few inches before I reverse. I rarely need to cycle all the way in and all the way out. I split mostly standing dead Incense Cedar and standing dead Black Oak.  Both split so easy that you can split just as fast with an 8 pound maul, but I get tired alot faster with a maul. :D  And no I cut the standing dead trees down first. ;D

slipshod

I found a three point splitter at a yard sale this summer and mount it on my John Deere. So far  there is nothing I have found that it won't split. Over the winter I want to make a saw horse style mount for it so I can run it horizontal when i am splitting mostly smaller chunks.

stonebroke

Solodan

Did you get the four way wedges? I have always wondered how they would work on that splitter. I am looking at that one also and am looking forward to you reports on how it works.

Stonebroke

solodan

No, I did not get the bolt on 4 way wedges because I do split some big wood, at least for firewood. I was afraid that the wedge is too far off center for a 20"-30" round. I will probably order a slip on 4-way wedge though. I think a 4 way wedge would work best on rounds 10"-12", but may be a hassle on the bigger stuff, I could be wrong though. :-\  I just did not want to have to unbolt those wings. Normally the stuff over 12" is for saw logs, but lots of times I do end up with some larger stuff going to firewood for one reason or another.  I'll let ya know how it works. I'm sure I will be happy though, I've never owned a brand new splitter.  ;D :)

Thank You Sponsors!