Need Log Splitter Help

Hi Everybody,

Does this sort of mounting of the ram to the wedge cause undo stress on the ram? Please see pics.

Thanks,

Roy

I think with the setup you have there, I'd try to keep the ram more centered on the wedge.

With a rigid setup like that I think in time something will give. Either the threads will let go or the rod end will snap. I would go with a clevis & pin type setup if its not too late, although it looks like it is already welded in solid. Just my 0.02

The wedge being rigidly attached to the rod has been used successfully on a few splitters. But some things that might cause problems are the wedge not being centered on the rod, the length of the slide being shorter than the height of the wedge, and the smaller diameter of the rod at the threaded end.

Leverage has to be considered when dealing with the tonnage of a log splitter. Consider that the 4 small rods can hold your tie-rod cylinder together but the same cylinder can bend a 6x6 beam if leverage is not taken into consideration.

i'm sure you centered everything before mounting and welding. by the looks of everything, you took your time and did plenty of figuring.

i'd fasten the end of that cylinder to the beam to prevent lifting. there's alot of force applied when splitting and when extended the weakest point is the end of the cylinder.

Cylinder height

John R said:

I think with the setup you have there, I'd try to keep the ram more centered on the wedge.

Click to expand...

The ram wound up below the center of the wedge because I was trying to keep the cylinder as close as possible to the beam so I wouldn't have a lot of leverage on the rear mount.

Roy

David Wayne said:

With a rigid setup like that I think in time something will give. Either the threads will let go or the rod end will snap. I would go with a clevis & pin type setup if its not too late, although it looks like it is already welded in solid. Just my 0.02

Click to expand...

The threads will be okay because the rod pushes up against the wedge metal to metal. It only relies on the threads on the return stroke. I started thinking about the wedge cocking back and how a clevis would let it rotate on the pin rather than flex the rod/ram. Side to side rotation would be handled by the ram rotating. Looks like a re-do. Better that than.....SNAP!

Roy

triptester said:

The wedge being rigidly attached to the rod has been used successfully on a few splitters. But some things that might cause problems are the wedge not being centered on the rod, the length of the slide being shorter than the height of the wedge, and the smaller diameter of the rod at the threaded end.

Leverage has to be considered when dealing with the tonnage of a log splitter. Consider that the 4 small rods can hold your tie-rod cylinder together but the same cylinder can bend a 6x6 beam if leverage is not taken into consideration.

Click to expand...

The slide is only 1/2 shorter than the wedge height right now. I guess I'll be making the slide longer on wedge attempt #2. I'm sure the clevis will have to be mounted off center on the wedge. I have a second big nut to use to make a clevis mount. Oh well.....

Roy

mga said:

i'm sure you centered everything before mounting and welding. by the looks of everything, you took your time and did plenty of figuring.

i'd fasten the end of that cylinder to the beam to prevent lifting. there's alot of force applied when splitting and when extended the weakest point is the end of the cylinder.

Click to expand...

You know that brings up a good question. Why aren't the business ends of cylinders on log splitters tied down. I guess they don't have to be like on bucket loaders. See attached pic. On the log splitter if the wedge cocked back and forth the pivot point of the clevis would move up and down and the pin would rotate slightly. The pin takes care of the rotation but if the front of the cylinder is tied down the ram will have to flex or snap. That's why you need a clevis mount on the far end of the cylinder too.......right? I mean look at the bucket loader you can see how the cylinders have to move. They actually swing back and forth. It's going to be a much smaller movement on the splitter but it's still there. Darn it, answered my own question.

Roy

We all can make suggestions but we are not engineers. Manufacturers with their engineering departments design a product, build prototypes, test, make changes, and finally put a product on the market which could end up with a design flaw that requires a recall.

Usually the best thing to do is allow for a little bit of flex when dealing with high forces.

Good luck on your project

Nice welds!

The basic principle here is that most hydraulic cylinders (nearly all in AG/construction) are designed for only compression/tension, ie push-pull. They are not designed to handle any bending loads, ie sideways loading to either end.

I deal with some marine cylinders that also serve to align the product and must deal with fairly high side loads. On these the piston is longer and has additional slide bearings, and the rod guide (endcap) is also longer to increase the bearing area.

All that is a long way to say, I agree with the need for a clevis and recommend against the idea of an addition tie between the rod end of the cylinder body and the I beam.

Also, regardless of how well the wedge is fitted to the beam there will be up and down rocking of the wedge as well. The first wedge I built I used 1/2" plate steel, it literally tore it in half from the force of the up and down movement. The second wedge was made from 1 1/4" plate steel. Now it's breaking 1/2" bolts!
Very nice work, and I hate to see you have to do it over, but better now than after you busted the rod on that cylinder!

radroy92 said:

You know that brings up a good question. Why aren't the business ends of cylinders on log splitters tied down. I guess they don't have to be like on bucket loaders. See attached pic. On the log splitter if the wedge cocked back and forth the pivot point of the clevis would move up and down and the pin would rotate slightly. The pin takes care of the rotation but if the front of the cylinder is tied down the ram will have to flex or snap. That's why you need a clevis mount on the far end of the cylinder too.......right? I mean look at the bucket loader you can see how the cylinders have to move. They actually swing back and forth. It's going to be a much smaller movement on the splitter but it's still there. Darn it, answered my own question.

Roy

Click to expand...

that may be true on stuff like bucket loaders, but there's a different set of physics going on with the log splitters. the force against the push plate or wedge tends to lift it when it has no where else to go. this is where your slide plate design becomes important: too short of a base, and it will bend your H beam.

i'm glad the ram was kept close to the beam, that reduces any chance of it springing up.

i followed the same principal when i built mine, but, after i bent one ram because it buckled up, i went with fastening down the end of the cylinder:

http://i89.photobucket.com/albums/k228/mga_01/log splitter/DSCF0207.jpg

i've split just about everything without a problem. i designed it so that the cylinder has no movement at all.

mga,

What does the other end of the cylinder mount look like? It appears that your cylinder sits right on the beam. Is this correct?

I agree with keeping the cylinder close to the beam but I would allow for at least a 1/4" of float in case of any beam flex.

triptester said:

I agree with keeping the cylinder close to the beam but I would allow for at least a 1/4" of float in case of any beam flex.

Click to expand...

Yep - no matter how beefed up you make this thing, there will be movement. You won't want that movement transferred to the seals or rod. Allowing the cylinder to have a small range of motion will reduce that chance.

1grnlwn said:

mga,

What does the other end of the cylinder mount look like? It appears that your cylinder sits right on the beam. Is this correct?

Click to expand...

yep, it does. the end of it sits in between two blocks with a 1" pin.

the end of the ram is held in the guide plate with a 1/2" pin

triptester said:

I agree with keeping the cylinder close to the beam but I would allow for at least a 1/4" of float in case of any beam flex.

Click to expand...

you may be right, but my cylinder is tight to the beam. as i stated before, we have split tons of wood of all kinds and types without any problems.

when building it, my theory was to keep the center as low as possible, with as little movement as possible. if i planned on keeping the cylinder stationary, that meant i had to design my push plate to give minimal movement....which is why it's only about 6 inches tall.

triptester said:

We all can make suggestions but we are not engineers. Manufacturers with their engineering departments design a product, build prototypes, test, make changes, and finally put a product on the market which could end up with a design flaw that requires a recall.

Usually the best thing to do is allow for a little bit of flex when dealing with high forces.

Good luck on your project

Click to expand...

Good advice thanks!

Roy