Angled back cuts
- Thread starter brendonv
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M
Mike Maas
Guest
It was a funny thread watching those degreed engineers struggle with such a simple process. 
R
Rotax Robert
Guest
Great post and answers guys, I can think of very little to add. About the only time a have used a slanted back cut (no face cut) is when I am in real small wood and am just stump jumping pecker poles to get them out of my way or thinning.
B
Banned by Squirrels
Guest
Pro:
There's a very specific set of circumstances that I will use an angled back cut; IF I AM strapped into a straight stick that is a leaner, (cutting against the lean) IF I HAVE a tag line tied, and IF IT IS small wood that I have to be behind it. (because of the whipping effect)
My reasoning is that under these set of events the angled back cut will mitigate the risk caused by the "push back" effect at the cutting point and I feel safer having that protection.
.02
There's a very specific set of circumstances that I will use an angled back cut; IF I AM strapped into a straight stick that is a leaner, (cutting against the lean) IF I HAVE a tag line tied, and IF IT IS small wood that I have to be behind it. (because of the whipping effect)
My reasoning is that under these set of events the angled back cut will mitigate the risk caused by the "push back" effect at the cutting point and I feel safer having that protection.
.02
C
Cedarkerf
Guest
That math was how to take practical knowledge and make a mess of it by guys that would take 6 of em three hours trying to fell a 10 inch tree in the middle of a field. That thread was bizzarre.
GASoline71
'cause chicks dig scars
It was a funny thread watching those degreed engineers struggle with such a simple process.
I thought the same exact thing.
Gary
rbtree
Climbing Up
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Bump. My extremely skilled climber seems to think the sloping backcut is a good thing. While I disagree with his reasoning (mainly that the tree would be less likely to fall back, only sit back) he has been using it for years with no bad results. Reckon he's never used it with wedges....
As far as a tree going back, if its going to break the hinge and go back, I'm of the opinion that it makes no difference whether the backcut is level or sloped. But, here's a thought. I wonder if it would be worse, not better with a sloped backcut. Couldn't the forward force caused by the sloping cut make the hinge wood break off, and slide the butt forward, which of course would tend to make the trunk fall backward?
In my relatively limited falling experience, I've not had a hinge break and a tree go over backward. I have them go sideways a couple times...I do remember once, misjudging a 110 foot spindly 12 inch fir. no rope, no wedges, but it sat back so hard that, later, when we got it over, after managing to get a rope up a ways, the imprint of every chain rivet was in both sides of he cut! Good thing we got it, as my pickup--and the house-- were where it wanted to go....
Tain't for me, but, man, does he get hot headed when I try to say something.. Course I coulda been more tactful.
As far as a tree going back, if its going to break the hinge and go back, I'm of the opinion that it makes no difference whether the backcut is level or sloped. But, here's a thought. I wonder if it would be worse, not better with a sloped backcut. Couldn't the forward force caused by the sloping cut make the hinge wood break off, and slide the butt forward, which of course would tend to make the trunk fall backward?
In my relatively limited falling experience, I've not had a hinge break and a tree go over backward. I have them go sideways a couple times...I do remember once, misjudging a 110 foot spindly 12 inch fir. no rope, no wedges, but it sat back so hard that, later, when we got it over, after managing to get a rope up a ways, the imprint of every chain rivet was in both sides of he cut! Good thing we got it, as my pickup--and the house-- were where it wanted to go....
Tain't for me, but, man, does he get hot headed when I try to say something.. Course I coulda been more tactful.
MasterBlaster
Administrator Emeritus
I'd say "That's stupid!"
N
NeTree
Guest
RB, the angled backcut can act as a force multiplier in it's own right; rather than the two faces in a 90 degree back cut closing and just putting pressure 90 degrees to the wood grain, the angled back cut can act as a splitting wedge against the stump by allowing the two angled faces to slide past each other, highly increasing the odds that if the tree sets back, the stump can split out, and keep the hinge wood from holding things together.
Angled back cuts are a noobie, bone-headed move, and I've cut plenty of them on purpose to illustrate the fact. (One of the nicer points of doing hand falling sub work is the access to literally hundreds of trees a day to screw around on.)
You can demonstrate this yourself, by using a two or three inch branch. Cut a notch, and then a 90 degree back cut, and bend it across your knee to pinch the back cut. Now do the same thing, except cut the back cut at say 45 degrees- and you'll see just what I mean.
Angled back cuts are a noobie, bone-headed move, and I've cut plenty of them on purpose to illustrate the fact. (One of the nicer points of doing hand falling sub work is the access to literally hundreds of trees a day to screw around on.)
You can demonstrate this yourself, by using a two or three inch branch. Cut a notch, and then a 90 degree back cut, and bend it across your knee to pinch the back cut. Now do the same thing, except cut the back cut at say 45 degrees- and you'll see just what I mean.
G
Gord
Guest
The only time I make a sloping backcut is when I'm felling a stem that's too close to another stem to get a cut in flat and too small to bore.
99% of the time a sloping backcut is just the plain wrong way to do it.
99% of the time a sloping backcut is just the plain wrong way to do it.
N
NeTree
Guest
I should also add that in rare cases, you have to make a cut in the root flare where the grain starts to run at 45 degrees; and in those cases, the angle allows you to keep the cut parallel to the wood grain- preferable if you're going to be doing some heavy wedging.
I usually avoid that by simply cutting higher up.
I usually avoid that by simply cutting higher up.
N
NeTree
Guest
Gord, yes... that's a time when your options become limited. In that situation, the stem is usually leaning in the direction of fall, anyways, so the odds of setback (and the associated problem with the angled back cut) disappear.
Be more subtle. Smile. Say "It seems like that might help control the tree until you start breaking down the input forces and angles and do the calculations. Then it turns out that it doesn't help and can actually create problems. I made a few of those cuts before I learned better."
Make the point without insult.... then if they argue, smile and say "You are fired."
Make the point without insult.... then if they argue, smile and say "You are fired."
Al Smith
Mac Daddy
To comment on a hinge breaking ,the only time for me was a bad leaner,too thin of hinge and stacking wedges . Not a good plan .--but the good plan to a bad plan was having a well planed escape route and being young and fleet of foot .
rbtree
Climbing Up
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Couldn't fire Dave, he's now a sub....plus he IS the best climber I've ever seen--at work anyhow. err, I should say at removals, as watching Greg Liu and Mark Chishom on the TreeHouse tree was great......and all Graham Mc did for me was wreck out a little 125 foot fir for craning later......in what was essentially tenny runners.....when i handed him a 335 Husky, he about used it to clean his fingernails.....
He's worked with Dan Kraus, former ITCC champ...he's faster.....incredibly sure of himself and competent....I thought I was good till I'd worked with Dave. but his backcuts? Ugghh...and when I showed him why I bore the center of the hinge on simple stick fells, he was unimpressed and ho-hum...
He's worked with Dan Kraus, former ITCC champ...he's faster.....incredibly sure of himself and competent....I thought I was good till I'd worked with Dave. but his backcuts? Ugghh...and when I showed him why I bore the center of the hinge on simple stick fells, he was unimpressed and ho-hum...
rbtree
Climbing Up
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Be more subtle. Smile. Say "It seems like that might help control the tree until you start breaking down the input forces and angles and do the calculations. Then it turns out that it doesn't help and can actually create problems. I made a few of those cuts before I learned better."
Make the point without insult.... then if they argue, smile and say "You are fired."
He actually tried to say the physics would be in its favor....which I don't see.....
he said, I've done it that way for ever...learned it from a old pro....don't care what Doug Dent says, Who is he anyhow and so what.....who cares if he certifies forest fire fallers......
treesandsurf
Treehouser
I got to meet Dave while I was out visiting Roger. Really nice guy and insanely fast removal climber from what I saw. Definitely knows his stuff that was obvious. Makes me curious how such a competent climber could advocate for slanted back cuts... Hmmm?
jp
jp
sotc
Dormant hero!!
sounds like he stopped learning somewhere along the way
Exactly!
You are setting up to stump shoot the tree, only when stumpshooting one omits the undercut and hinge, but the result will be the same.
T
TheTreeSpyder
Guest
The angled backcut gives several problems.
If you need to wedge, it pushes tree across hinge rather than rotate/ pivot on it. So, you take a shorter, more linear/non leveraged route/non-rotational to target giving less advantage of input distance to output distance(by taking more direct/linear route of force), and fight the hinge structure too(trying to push across it).
Also, the angled backcut makes a weak back stop against sitback. This is because sitting back (or wedging off); has a backstop across thinned piece of grain, rather than sitting back and force going down squarely into grain(if using a horizontal backcut properly). So, it takes more wedge force to push same load, and the backstop is weaker. We say horizontal, flat, but i think we all mean perpendicular to the grain.
i think the splitting at sit back comes from weak structures getting pushed across this slanted backcut, and prying the weakness apart. so, i don't think it happens on each occasion or species etc.
Also, as stated, it is harder to leave a proper hinge, steer with tapered etc. when using slanted backcut.
Now i have slanted backcut, when backside is against building etc., but minimizing the angle as much as possible; when i know i won't have to wedge. Can claim that the outreach of the backstop is farther from pivot of hinge, so can try to make case for more leveraged backstop, but; the backstop is so weakened as to nullify i believe.
If you need to wedge, it pushes tree across hinge rather than rotate/ pivot on it. So, you take a shorter, more linear/non leveraged route/non-rotational to target giving less advantage of input distance to output distance(by taking more direct/linear route of force), and fight the hinge structure too(trying to push across it).
Also, the angled backcut makes a weak back stop against sitback. This is because sitting back (or wedging off); has a backstop across thinned piece of grain, rather than sitting back and force going down squarely into grain(if using a horizontal backcut properly). So, it takes more wedge force to push same load, and the backstop is weaker. We say horizontal, flat, but i think we all mean perpendicular to the grain.
i think the splitting at sit back comes from weak structures getting pushed across this slanted backcut, and prying the weakness apart. so, i don't think it happens on each occasion or species etc.
Also, as stated, it is harder to leave a proper hinge, steer with tapered etc. when using slanted backcut.
Now i have slanted backcut, when backside is against building etc., but minimizing the angle as much as possible; when i know i won't have to wedge. Can claim that the outreach of the backstop is farther from pivot of hinge, so can try to make case for more leveraged backstop, but; the backstop is so weakened as to nullify i believe.
