felling cuts

[Mark]

Yo bud,

Its the first post i'v put on, I dont realy know how things work on Arbtalk at the moment.

Nice work though.

I've been involed with tree's for thirty years now.. tree surgeon for about 25 of em.. I'm now an Arb Officer.... I'm off to have a look at the site.

Mark

[TreeSpyder]

i stop before center to place back of hinge at widest part/center. This gives the widest pulling part of the hinge that is opposite lean; the most pulling power IMLHO. Which is most exemplified in a tapered/triangular shaped hinge. this widest part in tapered hinge is up against downward pull in a horizontal limb swept horizontally. To really test theories of hinging and felling; i think climbers have the advantage of being able to test same theories at diffeent angles to see if they hold water.

 

i prefer wide enough face to fold as far as i want before tearoff. Which is sometimes wide. But, usually on ground; just normal/easy face. In tree; rigging and swinging over, or bending it over far to pretitghten it's own line and tearoff later to have less drop and shock line less(works in combination with the tighter line fr less line shock); i use wide face more. But, then that is in smaller wood than felling, so easier to cut all that wood. Loggers use humboldt more; and the hard part of the wide face is the upper slant of that. The downward would be just an easy ride down after fighting a big saw uphill. Because in tree/in such situations i treat hinge as a 'disposable rig line' at butt, that i use so far; then cut free. So a normal rig line becomes a 2nd rig line; and this butt tie/ hinge is a helper rig line to place load into normal rig line.

 

The farther you bring hinge back; the more ballast of tree weight is helping the fall. But, the less leverage wedge and prybars have.

 

i also dutch with a kerf on lean side when i have to. This offers the non-lean side as path of least resistance/ gives lift to the lean side. In horizontal sweep, that is the downard side of the vertical hinge. Dutch across full face is what really gets you in trouble; offerning no path of least resistance at full and early close; more like jsut kerfing a head leaner.

[Kevin]

Ken, is the leverage not greater when placing the hinge aft?

Less weight to lift promting the tree over.

Too far back and the tree falls prematurely due to excess weight ahead of the hinge.

 

This is why that open face notch was used ...

 

[TreeSpyder]

Hey Kev-

 

Leverage of the CG is greater to fall/ more ballast of weight /angle to target on fall side of hinge; but that is a trade-off to loss of helpful forces on opposite side of hinge/compressed part of the hinge as pivot point more precisely? And yes, less weight(on load side) to lift and more ballast (on fall side)to help that lift. For, of the 3 positions ballast, load and pivot; altering pivot is always the most dynamic adjustmeant; for it is hooked to/effects both the other events. Where by the other events(ballast and load) are only hooked to one event(pivot) directly. So, pivot's changes take from 1 side, and give to the other; giving 2 changes at once for or against hitting target(thus the expression 'a pivotal change'). Thus increasing ballast and decreasing load in 1 move... Whereby, Increasing ballast or load, just changes that factor, not the opposing factor (IMLHO).

 

If the compressed part of the hinge is the pivot; the closer said pivot is to the lift of the wedge/prybar; the less leveraged length multiplier of said lift?

 

Yes "too far back..." but also less side to side control; as then the hinge narrows? Also, the release is all at one point/concetrated; more violent; than release fibers spread?

[bill]

is cutting the hinge away with the letter cut a bad idea? ive heard different points of view?

 

i read also that when topping trees, have a 75 degree gob so that the hinge breaks when the tree top is horizontal to the tree's stem. this reduces stem wobble.

 

also if you do a bore cut, when you cut the strap cut from below as there is a chance that if you cut above the saw could get trapped.

[Kevin]

is cutting the hinge away with the letter cut a bad idea? ive heard different points of view?

Bill, not sure what a letter cut is but you should never cut through the hinge when felling a tree, it's the only control you have.

 

i read also that when topping trees, have a 75 degree gob so that the hinge breaks when the tree top is horizontal to the tree's stem. this reduces stem wobble.

The greater the better to reduce the bending moment.

You want the top to leave the stem soon as possible, the longer it hangs on the greater the bending moment.

 

also if you do a bore cut, when you cut the strap cut from below as there is a chance that if you cut above the saw could get trapped.

That's correct.

[MasterBlaster]

This was a fun felling cut.

[High Scale]

A letter box cut is boring away the center of the hinge from the direction of the front/felling cut.

 

It has different names however, depending on world location, I was taught that it is a bore cut.

[TheTreeWiseMen]

I've always known it as a 'key hole' cut.

[vduben]

A letter box cut is boring away the center of the hinge from the direction of the front/felling cut.

 

It has different names however, depending on world location, I was taught that it is a bore cut.

 

is a bore cut not where youhave to fell a tree 1.5 times the size of the guide bar? and bore in the side and sweep around the back, you can also do the same on 2.5times the size i think where you bore into the mouth creating cut wood in the back because the bar will not go straight through and do a sweep around the back..