log splitter H or I beam question

[theboman]

Once upon a time on Ebay there was a homebrew log splitter fer sale but needed work. It was on nice sized I-Beam if I remember correctly but they used a big cylinder/pump and it bent the sucker badly! I ain't no welder just thought somewhere in the process somebody should have known better.

 

[Wayne_H]

The 4" deep beam is not going to have the section modulus (stiffness) needed for a splitter. We wouldn't use anything less than a W6x25 for 3" and 4" splitters @2400psi, and a W8x40 for above 4" bore splitters @2400psi. There is a considerable moment induced in the backbone of a log splitter from the eccentric load from the center of the splitter wedge to the center of the backbone beam. The stresses from the induced moment need to be added to the tensile stress, or combined stress.

Apply the splitter force (depending on the cylcinder and pressure) at the centerline of the wedge. Calculate the moment induced, extreme fiber stress, and add than to the fiber stress due to tension. If the beam is A36, which is the most common for older small sections, your allowable stress is 24 ksi. Make sure you are under the allowable. Check deflection the same way.

If you don't want to run the numbers, use a W6x25 for a 3-4" cyclinder at 2400 psi, a W8x40 @3000psi.

Michigan Iron is right. Don't look at the home cheapo ones that have 4 inch cylinders and claim 30 tons with a 6 inch beam.. I'm using W8x40 with a 5" cylinder. Check out the real splitters like Rayco or Timberwolf of PJ commercial products. They all use W8x40 steel....

Wayne

 

[SPYDERLK]

with the flex be reduced when I weld the 1/2 by 8" wide plate across the top

It certainly won't hurt.

I don't want to start a spitting for distance contest with MichiganIron, because if I were in the business of building these things for other people, then I'd order the right steel section to begin with, as he does. My name is going with the equipment, my future, my financial well being.

You just want to build a splitter out of some steel you have lying around. As long as you accept the caveat that MI has expressed and proceed with caution, you should be okay.
OldMech's splitter should be ample evidence of that.

I believe MichiganIron is addressing Oldmechs splitter described in post 9. I used a 6x4" I beam just like the OPs for my 18T splitter. The only thing I did is split a 3" pipe and weld it around the center of the web section to enable the beam to deal with the inevitable torsion forces induced. This is more important than the top reinforcement plate. That assymetrical reinforcement wont help strength much--the bottom of the beam will still see virtually unchanged compressive force somewhat near its limit. While that plate ruggedizes the top flange against damage from careless log handling, the torsional reinforcement is the bigger factor in sustaining the life of a beam that is approaching its performance margin. [Twisting causes exreme stresses.] Mine is 35 years old and has developed no issues. I attribute this also to avoiding any weld to the edges of the beam tensile flange and blending and strain relieving all welds to the beam using flap disc and needle scaler.
larry

 

[soulasphil]

I didn't build it (not good enough at welding) but my 13 ton vertical splitter uses a fat I beam. The only thing that gives in slightly when the log is real hard is the bottom plate.

 

[GE222]

Back to your original question #2. I can't say for sure, however I don't believe that your Ingersol tractor has a very high pressure hydraulic system. I believe that it may be below 1500 psi, but I could be wrong.

Anyone else have any more info on these tractors???

 

[trialsguy]

Well I am going to have to scrap the idea of the 1/2 plate that I have across the top as I have found out that it is hardened a little bit, came from some sort of a grader blade. When I was using it to build up the ram plate I realized that the welds were crystallizing when I had it tacked up to check fit I knocked it of my welding table and the tack welds broke away easily from the hardened plate side but not the other leaving kind of a cast looking divot in the metal, comes from the hardened steel cooling too fast or something another.

I have spotted a 6" X 12" H beam I think. looks to be 3/8 on the flat and only a 1/4 in the web but to me it doesn't look that sturdy for as big as it is it looks like it will twist easier then the smaller one I have.

I may just use the 4x61/4 and weld up the middle like what was posted unless I can get a heavier beam.

I dug up the manual for the tractor which is a 3018 model the hydraulics are stated to be 8 gpm pump @ 3000psi I figured it would run a 4" cylinder pretty good

 

[towmotor]

SPYDERLK wrote:

I believe MichiganIron is addressing Oldmechs splitter described in post 9. I used a 6x4" I beam just like the OPs for my 18T splitter.

I'm not trying to bolster a major league argument on a minor league issue here, but MI was referring to both the 4" section (OldMech) and either of the two "W6 x" sections that the OP has on hand, since what he recommended is substantially heavier.

I'll repeat (though a bit differently), that if the OP had asked "I've got $200 to spend on a chunk of beam for a splitter, what should I get?" then it would be stupid for him to get anything lighter than what MI recommended-owing to the fact that not only does MI possibly possess an engineering degree (or at least is able to perform a load calculation) but he also uses the recommended section(s) when he builds these things for other people .

If your splitter, SPYDERLK, is built from a lighter "W6 x" section than what MI recommended, then that fact provides some indication that such a beam will suffice, but for an 18t splitter .
Neither OldMech nor the OP provided that important detail, so any of us is going out on a limb to say "it'll last/not last".

I attribute this also to avoiding any weld to the edges of the beam tensile flange...

Gotta take a little issue with that. Properly welded beam flanges are in use worldwide, with good results. After all, beams are welded flange to flange (perpendicular of course) routinely, having much less mechanical advantage than lap welding to both flanges over a 5'-6' length, and they endure the test of time.

Granted, if one has no experience with welding, then bodging a log splitter together is not the ideal first project, no matter what weld we're talking about.

 

[SPYDERLK]

SPYDERLK wrote:

I believe MichiganIron is addressing Oldmechs splitter described in post 9. I used a 6x4" I beam just like the OPs for my 18T splitter.

I'm not trying to bolster a major league argument on a minor league issue here, but MI was referring to both the 4" section (OldMech) and either of the two "W6 x" sections that the OP has on hand, since what he recommended is substantially heavier.

I'll repeat (though a bit differently), that if the OP had asked "I've got $200 to spend on a chunk of beam for a splitter, what should I get?" then it would be stupid for him to get anything lighter than what MI recommended-owing to the fact that not only does MI possibly possess an engineering degree (or at least is able to perform a load calculation) but he also uses the recommended section(s) when he builds these things for other people .

If your splitter, SPYDERLK, is built from a lighter "W6 x" section than what MI recommended, then that fact provides some indication that such a beam will suffice, but for an 18t splitter .
Neither OldMech nor the OP provided that important detail, so any of us is going out on a limb to say "it'll last/not last".

I attribute this also to avoiding any weld to the edges of the beam tensile flange...

Gotta take a little issue with that. Properly welded beam flanges are in use worldwide, with good results. [After all, beams are welded flange to flange (perpendicular of course) routinely, having much less mechanical advantage than lap welding to both flanges over a 5'-6' length, and they endure the test of time.]

Granted, if one has no experience with welding, then bodging a log splitter together is not the ideal first project, no matter what weld we're talking about.

Hes using a 4" ram. That sizes the force at 18T at 3kpsi. The 6" I beam he describes will last at this force if it torsionally reinforced.

Putting abrupt strength transition near edges - particularly those that must endure significant and repeated elastic cycling is best avoided to favor longevity. Edges are prime sites for crack initiation, and the stress riser at an edge weldment is a risk to avoid when you want to use your metal effectively. Otherwise you just increase safety factor by imparting great rigidity; using more metal less efficiently to avoid the mental stress of better design.

[Im unsure of the weldment layout you are describing in your example. Also whether it is employed in an area where cyclic loading significant to the strength of the members will routinely occur.]
larry

 

[towmotor]

My example is drawn from the design and engineering of ship decks and watertight bulkheads.
Don't ask me any more (please).

Do the decks see the cyclic loading? I doubt it.
The bulkheads definitely see it.

I do not agree that a properly applied and, equally important, properly finished weld will cause greater stress, especially when the weld is parallel to the force being applied.
But that's just me.

Anyway, it looks as if our OP has found a chunk of steel that should handle the job, in anyone's opinion, and I don't want to hijack his thread anymore than I already have.

Unless, of course, someone wants to light off the next skirmish in the "wedge" war.

 

[trialsguy]

Thanks guys for all the info, who would have thunk that there is so much technical stuff behind a wood splitter, just kidding I realize the importance of all the information at hand. hence the reason for the questions.

My problem is I have a lot of resources to get this stuff free because its just laying around not being used. Plus I like to build stuff with what I have on hand Problem is I have to ask the right people the right questions to get what I need.

Before I started this thread I had no idea a beam went through all that it does just to split a chunk of wood. I spend more time googling and looking up a lot of words that have been used in this thread just to find out what the heck it meant, which is a good thing.

Now I am in the process possibly locating a larger beam but wont know anything for a couple days.

Right now it looks like all I will be out of on money is for a valve a couple hoses and fittings, maybe somewhere around 150.oo for around a 18t splitter, to me building it is more rewarding then using it, well maybe not in the long run as far as my back goes.

I like to build stuff but I do like to be comfortable using without the worry of somebody getting hurt so usually is over built.

I may have a contact for a 8x6x3/8 beam 9' long, Hope so!

Thanks again for the info and I will learn on!