hydraulic felling wedge.

[wills-mill]

The other thing worth looking out for is a toe jack.... you only need to enlarge the saw cut to slip one in

 

 

I've been semi seriously looking out for one last few months. You'd have to be careful on soft timber and biiig trees as the jack would probaby just chew into the wood.

[treequip]

Ah. well the tractor hydraulics option is never going to work, as the pump will not make the pressure.

As for having to use a tractor just to power a felling wedge....

 

The air jack idea is a good one though, if you did a little re-engineering on the jack.

 

The thing about the proper Silvey jacks is that they are light (made from Aloominum) and very powerfull - 45 tonnes from a tiny jack...

 

Fluid dynamics is going to have to differ with you on the tractor part. As I said the force the ram exerts is a function of pressure and area. Lower input pressure just means you need a bigger ram.

 

I made a portable log splitter to carry on the chipper for busting up the odd bit of dross timber that was that bit too big to chip. I adapted it to double as a felling aid. It made better than 13 tons of force (granted it had a 4 inch ram bore) and I have shoved more scabby pops about with it that I care to remember. It ran from the chipper but any hydraulic supply would do. Only the flow would change (annulus speed). Clearly not suitable for every job but effective (and dirt cheap) nonetheless.

 

I did have thoughts on using a spare enerpac ram and pump upping the force to 10,000psi and 90 tons but the one concern I had was shoving the stem up and off the hinge rather than over it.

 

Andy

[Mr Ed]

Fluid dynamics is going to have to differ with you on the tractor part. As I said the force the ram exerts is a function of pressure and area. Lower input pressure just means you need a bigger ram.

 

 

Andy

 

Yes, Theoreticaly you could get a tractor powered ram to give 45 tonnes... you would need a ram with a 6 inch rod, which in turn would be probably beyond carrying, and would be near impossible to cut into the back of a stem...

[treequip]

The rod has nothing to do with the pushing force of a ram. It only affects the pulling force and the speed of the “inward” stroke. As I have said before the pushing force of a ram is a function of the bore (area) and the pressure.

 

Yes you need a bigger ram but who says you need 45 tones? I can give you 145 tones in not much more size but do you need it? What matters is the surface area in relation to the force. Don’t forget that the Silvey jack is from the land of big redwoods.

 

I managed some big orrible trees with a weedy 13 tonnes and if you design it right you don’t need to cut it into a stem.

 

Andy

[Mr Ed]

OK Mr pedantic. to give you 45 tonnes of pressure with 2000 psi you would need a ram with an internal bore approx 6 inches wide. Given that we're talking about pushing trees over, I personaly prefer a rod that is as close to the internal bore as possible. In the case of the silvey, its identical, as its a one way system with sprung return.

 

As to the amount of force needed, you can use as little or as much as you like my friend. I was merely using the silvey (world market leader) as a comparison - when we built our own version, we built it very similar.

 

And if I want to do it without cutting into the trunk, I use my Excavator.

[Tom D]

You certainly need some serious tonnage, I once tried tipping a big open grown douglas fir with an 8 ton bottle jack, it was very hard work. I think Ed's right, to get any serious tonnage you need a massive heavy ram. A tirfor winch or any winch for that matter would be far better, one ton at 50 foot is probably better than 20 ton at the bottom.

[treequip]

OK Mr pedantic. to give you 45 tonnes of pressure with 2000 psi you would need a ram with an internal bore approx 6 inches wide. Given that we're talking about pushing trees over, I personaly prefer a rod that is as close to the internal bore as possible. In the case of the silvey, its identical, as its a one way system with sprung return.

 

As to the amount of force needed, you can use as little or as much as you like my friend. I was merely using the silvey (world market leader) as a comparison - when we built our own version, we built it very similar.

 

And if I want to do it without cutting into the trunk, I use my Excavator.

 

Sorry you think accuracy is pedantic but if you are offering advice it ought to be accurate. If you want pedantic it’s not a one way system, it’s called a single acting ram.

 

Like I said 45tons is nice but I managed with a fraction of that at a fraction of the cost.

[treequip]

You certainly need some serious tonnage, I once tried tipping a big open grown douglas fir with an 8 ton bottle jack, it was very hard work. I think Ed's right, to get any serious tonnage you need a massive heavy ram. A tirfor winch or any winch for that matter would be far better, one ton at 50 foot is probably better than 20 ton at the bottom.

 

You are quite right, about the effort involved. Ed hit on it earlier in the thread with the size of the pump involved. High pressure hand pumps have a very low displacement and are easier to pump but are slower.

 

A line in the tree is also mechanically far more efficient than jacking. It also has the advantage that you are pulling the tree onto the hinge rather than jacking it off the hinge.

 

Out of interest I set an experiment with a 90 ton “enerpac” ram I managed to snap a quite substantial hinge on a lump of 30” diameter poplar. I decided the enerpac was a bit much for the job. I would like to think that stateside they use the jacks on much larger trees with bigger hinges.

 

Andy

[Mr Ed]

Sorry you think accuracy is pedantic but if you are offering advice it ought to be accurate. If you want pedantic it’s not a one way system, it’s called a single acting ram.

 

Like I said 45tons is nice but I managed with a fraction of that at a fraction of the cost.

 

Accurate terminolgy is good, but I'm really not offering advice, just my own experience. I would not build my own again, I'd just buy the silvey.

 

And so far my knowledge has enabled me to design and build logsplitters and chipper infeed systems, rebuild hydrostatic forestry transmissions, wire and plumb harvesters & forwarders, install cranes, hooklift systems, heavy winches and crushers.

 

Silly really as I hate hydraulic oil.

[Jonny69]

Well, this is an old revival.

 

Yesterday, after spending what felt like an eternity smacking wedges I though of a solution that may work.

 

Has anyone used a cone splitting wedge in a similar way to the rattlewedge.

 

Except, weld a big nut on the back and drive it in to the back cut with a cordless impact driver. Mine apparently does 600nm and it knocks off rusty wheel nuts with ease.

 

Could also take it up the tree with you.

 

It would be a hell of a lot more portable than the RAM type wedges, and you could even split some firewood if you get really bored.

 

Any opinions on whether this will work?

 

Thanks

 

Jonathan