angled back cut when felling

thank you for all the replies. my current employer was on the jobsite when i was notching a tree, and he stopped me and to explain that i should angle the cut because i would get a bit of mechanical advantage. i told him i had never heard that and just use wedges if i feel the need and he told me i shouldnt usually need them if i do it his way.
i brought this up here because i had never heard this before and i trust the opinion of a bunch of pro. arborists over one outdated and stubborn one
 
Fair enough.
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I stand by the points I made in the podcast. I agree that a stump split may occur, but dis agree it is more likely than hinge failure due to increased stressing from a raised fulcrum.

You will probably never convince me that any slanted back cut, even in an ideal situation, generates mechanical advantage. Just don't see it. The back cut is the door knob, the tree the door and the hinge the hinge. Face cut is the space for the door to swing.

Tony

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I respect that and the more I think about this subject the more I realise its likely to be 50/50. I will try one more time to convey my point about leverage as simply as I can.

If the back of the back cut is the fulcrum for failing the hinge (it is but there are 2 ways of picturing it) then the farther from the hinge said fulcrum is the LESS leverage there is to fail the hinge. End of story.
 
Horizontal. Slightly upward possibly on old growth fir if you have a ton of pitch likely to run. It will run downhill away from your bar and chain.
 
This thread got some good action today.

I can only relate to my experience with the trees in the NorthEast. I haven't yet found a need to form a sloping back cut unless I'm felling out a co-dom and I don't want to contact the remaining stem.

Willy, I should have been more clear about the lift when stacking wedges, in that it gives more distance not force, yes...In that light, I have experienced felling situations in which multiple wedges in the back cut can be hit alternately. This can get you more result than a single wedge. When one wedge resists being driven any farther into the back cut, you can use others to gain more lift by alternating.
 
Wow people still argue about this.
If someone starts talking about the benefits of sloping back cuts, I walk away, I do not care how much experience they have, they just sold the home in my opinion, and Ill have trouble taking anything they say in the future seriously.
To me the sloping back cut idea is a weeder outer, it weeds out the crackpots from the...non crackpots ?
Bring on the slopers.
 
I've seen Tony's podcast before and it's solid. A sloping back cut is a farmer cut. It's not a professional technique.
If you think a tree might lean back because of wind or an inherent lean or weighting then you need to have wedges or put a rope on it.
The amount of leverage the height of tree above the hinge has compared to that bit of propping provided by the slanted wood is not comparable.
 
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Wow people still argue about this.
If someone starts talking about the benefits of sloping back cuts, I walk away, I do not care how much experience they have, they just sold the home in my opinion, and Ill have trouble taking anything they say in the future seriously.
To me the sloping back cut idea is a weeder outer, it weeds out the crackpots from the...non crackpots ?
Bring on the slopers.

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No one is saying there is an advantage to a sloping back cut. I don't feel like you can be a great cutter until you unferstand why. Any average cutter can learn the basic rules and be proficient. Great cutters know all the ins and outs.
 
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I've seen Tony's podcast before and it's solid. A sloping back cut is a farmer cut. It's not a professional technique.
If you think a tree might lean back because of wind or an inherent lean or weighting then you need to have wedges or put a rope on it.
The amount of leverage the height of tree above the hinge has compared to that bit of propping provided by the slanted wood is not comparable.

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I agree Tony's podcast is well thought out, well made, and does an excellent job saying an angled back cut should not be used. I also agree an angled back cut should not be used.

The point made about increasing leverage on the hinge is indeed incorrect though. It can be proven using simple math. If you guys are happy teaching it that way more power to you.

I will no longer argue these points as it is clear we are making no head way. I will put my money where my mouth is by putting 500 of my hard earned dollars against anyone who will match it to hire an independent engineer to settle this dispute. Who ever is correct takes home the remainder of the cash.

Maybe this is immature but I am very stubborn and see no better way to prove my point. It wouldn't bother me so mutch if the error wasn't in an educational movie.
 
i know this gentleman can be a bit of a cowboy and is set in his ways, so i dont ever take what he says and run with it. stuff like this is one of the reasons why im in the process of leaving my job. i want to be the best arborist i can be but i will only ever know what i am taught and shown.
im young and still wet behind the ears, but i know enough to know who to listen to.
But im in the process of buying a house and was told if i was to change jobs now it would not look to good in the eyes of a loan underwriter. BS!
 
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thank you for all the replies. my current employer was on the jobsite when i was notching a tree, and he stopped me and to explain that i should angle the cut because i would get a bit of mechanical advantage. i told him i had never heard that and just use wedges if i feel the need and he told me i shouldnt usually need them if i do it his way.
i brought this up here because i had never heard this before and i trust the opinion of a bunch of pro. arborists over one outdated and stubborn one

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Makes for some good reading.
Jeff
 
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.... some sort of mechanical advantage out of it ....

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Still sounds like the same mechanical advantage, using angles, that I get from my log splitter.

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I did some checking on wood strength.

The tension force that I can apply to a hinge using such things as wedges and jacks, ranges from about 13,000 psi to over 22,000 psi depending on species. (pine being low, poplar high)
Pushing perpendicular to the grain such as with this angled back cut I am only able to apply between 450 psi and 550 psi.
Just goes to show why the log splitter works so well with the grain as apposed to across the grain and why I would rather have the tension and compression forces working to lean the tree rather than have forces splitting it.
 
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I thought the reason for the angled back cut is to act as a stopper should the tree barber chair.

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Ironically, most barber chairs I have ever seen were on sloping back cuts.

If you want to prevent a barber chair, learn to bore cut.
 
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thank you for all the replies. my current employer was on the jobsite when i was notching a tree, and he stopped me and to explain that i should angle the cut because i would get a bit of mechanical advantage.

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Yeah, you would do yourself good not to work for someone like that. This is how people get killed.
 
This looks like another "know why and when to use it" situation. 99% of homeowners I have seen use this cut believe that it "prevents" the tree from going over backwards regardless of lean, wind, weight, etc.. They are looking at it from a "sit back" perspective only, as in the back "wall" I just created will hold this tree up "if" I screwed up.

For the 1% that put thought into using an angled back cut to give an advantage - if it needs that extra "advantage" to get it to go - put a rope high in the canopy and pull - an easy, no guesswork or I "think" this will work back cut needed.

When to use it? When it is not possible to come in from the backside - co-dom, fence, wall, etc...
 
It's about the hinge: thickness, length. Different situations require different backcuts. Are your feet on the ground? Are you 85 feet up? The only time I use a sloping backcut is when there is no hinge. aka salami cut. If your are standing on the ground there are many reasons not to use a sloping backcut: 1. chainsaws cut much better across the grain, the cutters are designed and sharpened to cut across the grain, not rip. 2. The shortest distance between two points is a straight line so why cut more wood than you have to? 3. Sloping backcuts are in the same instruction manual that includes wound paint, DDT and blood letting with leaches.
 
The old logger that taught me to drop trees, showed me the angle back cut. He would cut, split and deliver 130 cords of wood a year, plus take down trees for people. I have used it for many years, and it has never failed me. He started in the 30's with a cross cut and axe. Been gone to see the lord for about 10 years, but said it just kept a tree where it was suppose to be, if a breeze came up. Theory goes out the window to experience.
 
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