Cylinder for log splitter questions

[4570Man]

If you were only using a single way knife the beam probably wouldn't twist. It's hitting a tough place on 1 side of the horizontal part of the 4 way that makes it twist.

 

[LD1]

Dad's huskee 27 ton splitter twisted the beam when still under warranty.

The wedge tried to follow the twisted grain of a knarly piece of wood....and took the beam with it.

Was replaced under warranty. Hasn't happened again

 

[muddstopper]

Go big or quit now on the beam. That's another lesson you can learn at my expense.

The first pic is a 8x8 by 32lb beam. You can see how I plated the top and boxed one side of the beam. I also boxed the other side.
The second pic is of the boxed wedge just hung on the beam. It will be reinforced a lot more before it over with, but the box is setting on a 36in widex 3/4in thick plated that extends about 2ft under the bean and is also fully welded to the beam. I dont know if you can tell in the pick how I gusset welded the cyl base supports into the beam. Those supports are 2in thick.

 

[4570Man]

Here was my original plan for a beam. It would've been nearly indestructible. And I had the materials to do it. I abandoned that idea when I found an already built wood splitter for 25 dollars. It had a 3.5 cylinder and a single way wedge. I removed both of those and "upgraded"

 

[polemidis]

The first pic is a 8x8 by 32lb beam. You can see how I plated the top and boxed one side of the beam. I also boxed the other side.
The second pic is of the boxed wedge just hung on the beam. It will be reinforced a lot more before it over with, but the box is setting on a 36in widex 3/4in thick plated that extends about 2ft under the bean and is also fully welded to the beam. I dont know if you can tell in the pick how I gusset welded the cyl base supports into the beam. Those supports are 2in thick.

That plating you did on the top surface gave me an idea: Do the whole length but the very end were the horizontal 4way wedge is. So I will lower the four way down and out of way if I split small stuff that need to be splitted only in half.

But where is the limit guys? What is the point that "overbuilding" something just adds unnecessary weight? It looks like I will have to learn the FEM module to analyze the stress on the metal.
Actually the real question here is about the frame of the firewood processor, which in the design is just 2"ﾗ2"ﾗ⅛" square tubing. I am just wondering if that to weak... Anyway. thank you all. The plan is looks good, I will start soon to do the math for the hydraulic system. Btw, the "Industrial Hydraulics Manual is AWESOME book!"

 

[4570Man]

I'm not sure how to determine you overbuilt a wood splitter without overbuilding it. There's no engineering handbook to deal with the forces involved.

 

[muddstopper]

That plating you did on the top surface gave me an idea: Do the whole length but the very end were the horizontal 4way wedge is. So I will lower the four way down and out of way if I split small stuff that need to be splitted only in half.

But where is the limit guys? What is the point that "overbuilding" something just adds unnecessary weight? It looks like I will have to learn the FEM module to analyze the stress on the metal.
Actually the real question here is about the frame of the firewood processor, which in the design is just 2"ï¾—2"ï¾—⅛" square tubing. I am just wondering if that to weak... Anyway. thank you all. The plan is looks good, I will start soon to do the math for the hydraulic system. Btw, the "Industrial Hydraulics Manual is AWESOME book!"

I had to put my box wedge ahead of of the hbeam to be able to raise and lower it, hence top plating all the way to the end of beam. My other splitter, I just plated to the adjustable wedge so that when the wedge is lowered, the 4way is below the top of the beam the same as you are suggesting. Of course my wedge is a 6way so even lowered all the way, I am still splitting 4 ways.

I look at over building as insurance against breakage. On a normal splitter, over building leads to a heavy machine and makes it hard to move around by hand. With a processor, it doesnt matter how over built or under built it is, you still aint going to move it by hand. My truck wont care if the machine is a few hundred lbs over weight because of being over built, but my back will care if I have to rebuilt the machine if something breaks because it wasnt strong enough. Reason for over building my processor beam, twin 4.5 in dia cyl's pushing 50 tons.

 

[4570Man]

Eastonmade has the best design for an adjustable height wedge IMO. Instead of an I beam they use 2 heavy plates running side by side. Another heavy plate welded in between running perpendicular to those two for a cylinder mount. At the other end they have 2 plates welded in the middle with a gap that makes a nice track for the adjustable wedge.

 

[FarmWrench]

Thank you all. Muddstoper, no intend to use anything out of specs man!
Ok, I abandon the idea of 4". probably going to 5" I
I understand the bending forces on the beam. I think that by keeping the cylinder as close to the beam as possible will limit that stress. But what about twisting? Is it a big stress? I do not get how the twist force is generated. maybe from weird knotty logs?
I believe the trunnion mount will cause less bending forces since the distance between the rods is only 3.5" right?
Thats a rough CAD of the splitter part, no much detail yet though. View attachment 531551

One way to reduce twisting force is to allow the blunt end to pivot. Take a look at the Canadian built "SplitFire" for an excellent explanation.

I've used pivot blocks on a lot of splitters that would twist and spring out the pieces of wood.

Another thing is how much bearing area and leverage the slide has on the beam.