Splitter - how much force when cylinder retracts?

[BlueRidgeMark]

On a lot of the stumps the backhoe had to dig to cut roots before it could pull the stumps. The backhoe had 4 and 5 inch bore cylinders I don't think the log splitter setup will work.

How big? I'm only talking about 2-3". Anything bigger I wouldn't try!

 

[BlueRidgeMark]

With the capability of 20 tons of pulling force what size steel cable would you need? Here is a wire rope sling rated at 7.2 tons if you choke it. The wire rope is 1" dia.
http://www.grainger.com/Grainger/items/1DNE4

I don't think I'll need anything close to that. Remember, I only need something that will handle the stumps grip, not the power of the splitter.

I've been pulling stuff like this with a come-along, and it's slow going, but it does the job. So, I think a 5/16 cable (which is bigger than my come-along cable) would do the job. Maybe go 3/8".

 

[BlueRidgeMark]

I think I have a better mousetrap. This will require some building, but avoids all the angle & bracing issues, plus, I can get some leverage.

The splitter pushes DOWN (red arrow) and this makes the other end go UP (blue arrow).

I can vary the leverage by moving the fulcrum (green arrow).

Comments?

 

[kevin j]

it takes 3 tons to get the stump to break free, there will never be more than 3 tons of force applied.

That means my brace only has to support the 'break free' force, not the whole 20+ tons.




nope-you have to design for whatever force the cylinder could apply, such that force does not make the system unsafe. You could lower the RV setting, but thats unlikely. So the system has to be stable, safe, not tip over, not break parts, at the stall force. Guaranteed you will stall the cylinder without knowing it. bigger stump, or roots grown around a rock, or just one more to pull that's a bit bigger.

The two legs out in a Y shape is a great idea. Would need to be attached with some heavy pins or braces, maybe tubes up to the top of the cylinder area.

I think you can get there, do lots of small ones.
Do have to think of how much setup time to move to next stump, set up and pull. vs. snagging witha backhoe.

How about some of the J shaped hooks for rear 3 points of tractor? commonly for rock picking out of the ground, but used for snagging roots also. FarmShow paper has them shown occasionally.

As the story progresses, cables and pulleys make me uneasy. Yes doubles the force, but maybe better to stall and force stopping at lower force, smaller stumps. Doubling for force means all the structure may not take it, and there is more stored energy in the 'spring' of cables and parts that can fly if something goes wrong.

 

[drmiller100]

when the red arrow pushes down, it will lift the gizmo that holds the ram.

all you need is some weight to hold the gizmo down!!!!

sure would be easier to build legs that straddles the stump.

 

[triptester]

Sorry about that I missed the 3"dia.. A chocker around the wedge should do the trick if the return detent doesn't kick out.

I have seem a hand tool on the web made just for that., but can't remember where.

In your last post you show a lever. Consider a post clamped to the toe plate with a roller on top. Then a cable from the wedge up over the roller down to the stump.

 

[BlueRidgeMark]

when the red arrow pushes down, it will lift the gizmo that holds the ram.

all you need is some weight to hold the gizmo down!!!!

sure would be easier to build legs that straddles the stump.

Doh! You're absolutely right!


Yup. So I should do it this way:




Now the down forces are at the red arrows, and the up forces are at the blue. If the stump is halfway between the splitter and the fulcrum, it will be pulled up at half the speed of the ram return, but with twice the force (minus any friction losses, which should be negligible).


At this rate, though, it's getting to be more complicated than it's probably worth. I might as well fabricate some beefy extensions to the foot plate, and go back to Plan 1.

Or just rent the backhoe. I was hoping I could figure out a simple way to do this, so I can whack at them onsey-twosey in the evenings, and get all the small stuff that way. Then rent a backhoe for the big stuff all in one day.

My place was just let go by the previous owners, and the back was an overgrown mess of saplings & vines. I've downed all but 3 or 4 of the saplings, and I have a monster brush pile, and many dozens of stumps to deal with...

 

[BlueRidgeMark]

I have seem a hand tool on the web made just for that., but can't remember where.

Are you thinking of the WeedWrench? I bought one last year, and need to post a review here. It won't touch a 2 or 3 incher. Not even close. Maybe in pure sand...

In your last post you show a lever. Consider a post clamped to the toe plate with a roller on top. Then a cable from the wedge up over the roller down to the stump.

I'm not able to picture what you're describing. Can you elaborate?

 

[BlueRidgeMark]

it takes 3 tons to get the stump to break free, there will never be more than 3 tons of force applied.

That means my brace only has to support the 'break free' force, not the whole 20+ tons.

nope-you have to design for whatever force the cylinder could apply, such that force does not make the system unsafe. You could lower the RV setting, but thats unlikely. So the system has to be stable, safe, not tip over, not break parts, at the stall force. Guaranteed you will stall the cylinder without knowing it. bigger stump, or roots grown around a rock, or just one more to pull that's a bit bigger.

Yes, you are right. My way works only if everything goes perfectly. If Mr. Murphy shows up, I could be in deep doo doo.

The two legs out in a Y shape is a great idea. Would need to be attached with some heavy pins or braces, maybe tubes up to the top of the cylinder area.

Yeah. Think 3" galv pipe would do?

I think you can get there, do lots of small ones.
Do have to think of how much setup time to move to next stump, set up and pull. vs. snagging witha backhoe.

Indeed! If it's not simple & quick, the setup time would wipe out any gains.

How about some of the J shaped hooks for rear 3 points of tractor? commonly for rock picking out of the ground, but used for snagging roots also. FarmShow paper has them shown occasionally.

I'm not familiar with these. I'll do a search.

As the story progresses, cables and pulleys make me uneasy. Yes doubles the force, but maybe better to stall and force stopping at lower force, smaller stumps. Doubling for force means all the structure may not take it, and there is more stored energy in the 'spring' of cables and parts that can fly if something goes wrong.

Agreed. I think my last drawing is a better method. I think there's more control, less chance of somehting going PING and flying where I don't want it.

What do you think?

 

[Frank Boyer]

I've used a crawler/loader/ hoe (12 tons) and an excavator (16 tons) for doing stumps. You are not going to do much of a stump with a splitter ( about 700 pounds). It might do more than a shovel and pick.

 

[triptester]

Are you thinking of the WeedWrench? I bought one last year, and need to post a review here. It won't touch a 2 or 3 incher. Not even close. Maybe in pure sand...




I'm not able to picture what you're describing. Can you elaborate?

This post up from the toe plate would have a roller on top. A bracket would be needed to hold the top or roller end in position. A guard would be highly recommended in case of cable snap. A cable would run from wedge up over post with roller down to stump.

 

[wireedm]

Doh! You're absolutely right!


Yup. So I should do it this way:




Now the down forces are at the red arrows, and the up forces are at the blue. If the stump is halfway between the splitter and the fulcrum, it will be pulled up at half the speed of the ram return, but with twice the force (minus any friction losses, which should be negligible).


At this rate, though, it's getting to be more complicated than it's probably worth. I might as well fabricate some beefy extensions to the foot plate, and go back to Plan 1.

Or just rent the backhoe. I was hoping I could figure out a simple way to do this, so I can whack at them onsey-twosey in the evenings, and get all the small stuff that way. Then rent a backhoe for the big stuff all in one day.

My place was just let go by the previous owners, and the back was an overgrown mess of saplings & vines. I've downed all but 3 or 4 of the saplings, and I have a monster brush pile, and many dozens of stumps to deal with...

That'll work as long as the beam is big enough. A 4" I-beam should take care of it.

 

[BlueRidgeMark]

This post up from the toe plate would have a roller on top. A bracket would be needed to hold the top or roller end in position. A guard would be highly recommended in case of cable snap. A cable would run from wedge up over post with roller down to stump.

I gotcha now. That would need some side bracing... Hmmm. Worth considering, since it wouldn't require quite a stout a beam as the 'seesaw' approach, as wireedm pointed out...



This is what I like about this place - lots of good brains, lots of good ideas.

 

[CylinderService]

Your last drawing looks like the safest and also the easiest on your splitter. And it doubles the force via the lever. Doubling the force doesn't mean you will always use twice the force, it means the splitter will always take only half the load of pulling the stump. If you need more force just attach the cable closer to the fulcrum.
Who was it said "Give me a lever and a place to stand and I can move the world."? Isaac Newton?

[email protected]

 

[BlueRidgeMark]

Your last drawing looks like the safest and also the easiest on your splitter.

That's what I was thinking.

And it doubles the force via the lever. Doubling the force doesn't mean you will always use twice the force, it means the splitter will always take only half the load of pulling the stump. If you need more force just attach the cable closer to the fulcrum.

Yeah, I was thinking it would make sense to provide multiple attachment points along that beam, so you could vary the pulling force for different stumps. Closer to the splitter for greater speed on smaller stumps, closer to the fulcrum for greater force on bigger ones.

Who was it said "Give me a lever and a place to stand and I can move the world."? Isaac Newton?

Archimides, I think.


Thanks for the input, Don! I know you went out of your way.

 

[triptester]

The only problem I see with the lever setup as shown is that the only force the splitter can apply is it's weight, unless the lever's pivot is attached to the splitter.

 

[Crofter]

Your splitter stroke will hardly give you enough takeup if you use any force multiplying levers or pulleys. Ground compression and spring will likely require several pulls and rehooks. I have pulled lots with tractor backhoe and I would say the muss fuss and bother of trying to use the splitter is not worth it. See if you can find a hoe owner and see if you can barter some of your time at what you are good at, then you will both be working efficiently. That size of stump should not take him much more than 2 minutes a piece max if access is reasonable. you will be busting your arse for half an hour or more. Having my own hoe makes me awfully stingy with my own labour, lol!

 

[wireedm]

Your splitter stroke will hardly give you enough takeup if you use any force multiplying levers or pulleys. Ground compression and spring will likely require several pulls and rehooks. I have pulled lots with tractor backhoe and I would say the muss fuss and bother of trying to use the splitter is not worth it. See if you can find a hoe owner and see if you can barter some of your time at what you are good at, then you will both be working efficiently. That size of stump should not take him much more than 2 minutes a piece max if access is reasonable. you will be busting your arse for half an hour or more. Having my own hoe makes me awfully stingy with my own labour, lol!

We all here like to "beat the system" if you will, a "do things with what you've got to work with" mentality, and save a dollar even if it takes you all day to do it. There's satisfaction in that.

Otherwise, just saw the trees just above the ground and go rent a stump grinder. Nah, too easy. lol

 

[drmiller100]

your last pic works.

now, look at the ram. move everything over to the right, and make a V shaped legs that go around the stump.

now just hook the stump to the end of the ram, and retract the ram.

 

[Kydan]

So if you beef up the foot plate some what and widen it add a little more length A cut out to fit around the stump,You have to make a center plate to bolt back in there when your splitting logs. How big would that foot have to be?14 to 16'' wide ?would look like Two 4'' or 5''wide X 14'' or 16'' length forks With the cut out being 6'' wide or so center would give you room to get around the 3''stump then you would be directly over the stump for a straight center pull .But I wonder if it would work? A splitter with fast return might be
dangerous ? Another tool sure sounds good.