Back cut below gob cut?

[Spruce Pirate]

Gob? Undercut I think. Anyways, the backcut is always above the undercut, you do not want the tree coming back at you. I prefer a Humboldt undercut, never seen one here. Humbolt is better if the log is going to the mill.

 

Gob, gub, mouth, face all mean undercut.

 

 

 

There are times where I have winched trees with dead tops. Back leakers and limited sound wood higher up to anchor the pull line to.

 

Setting the pull line low in sound wood and then having the back cut under the bottom of the face cut creates a lip so you don't pull the butt off the stump when winching.

 

The faster the winch the better. I wouldn't recommend it on a hand pull or a tirfor.

 

It definitely works in that scenario, it was an old school cutter who showed me that one.

 

In nearly every other application it would be level or above the bottom of the face cut.

 

You see here, the top cut, although good thicknes in hinge has no complete fibers. The bottem cut has the most complete fibers

 

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Something to think about

 

1-2 inch step depending on the size for most trees-helps minimise timber pull on the hinge and will move itself off the stump when gob closes. Backcut level with undercut when the tree needs winching back off the stump-no step in the way. Either level or just below undercut when felling heavy leaners with a wedge or a tractor winch- hinge holds stronger. Backcut below undercut when winching and you do not want the tree to fall behind the stump.

 

Basically all of the above are about right in my opinion. I'd only really use it if I wanted to make sure and keep something on the stump and with a winch. Like if you're felling up hill with a winch pulling them in. Fell it with the back cut below, pull it in with the winch, if the line goes slack the back cut being below means the butt will stay on the stump without the hinge snapping, tension up the line again, sever the hinge and winch it up. If you use a conventional cut with the back cut above and the hinge snaps you can end up with the tree sliding back down the hill.

 

A lot more difficult to get the tree to fall, hence why I'd only use it with a winch, in normal circumstances back cut always above. Rule I was taught was same as hinge thickness - 1" per 1', ie 1' diameter tree = 1" thick hinge, back gut 1" above bottom of gub.

[Vespasian]

Hi all, newbie here

I'm working with a fella who got his ticket six months ago, and I'm concerned he might have got the wrong end of the stick with this. I don't have a ticket yet, but I have worked around many people who do, and I have never heard or seen anyone put the back cut below the gob. Is this something new? Or maybe for a particular situation, so slopes/leaners/splitty types? The fella reckons that's how he was taught by his instructor and is continuing to do it this way as standard. I'm just worried he continually sets himself up with a tree that sits on the saw and wants to go in the opposite direction to the gob. What do you think?

 

After reading through this thread, it looks to me like your man is doing it all wrong.

Whether to wind you up,!!!! or he doesn't quite remember how he was taught to cut a tree is down, is up to you to investigate...

 

I'm going for the wind up merchant....

 

If your not sure of the correct way, or your fella isn't sure..... tell him to read this thread or look at a thousand and one Utube vids on how to chop down a tree down correctly....

[Stephen Blair]

I often fell lower than the bottom of the gob, it just holds a bit longer, so if I have a leaner and only a wedge and no better assistance and I have to take more out the hinge than I'd rather, I will go lower on the holding side.

I wouldn't do it on sycamore, holly, chestnut or beech.

I do on Oak, Birch and softwoods!

[JLA Arborists]

Have a look at 'rate my hinge' thread. 1082 posts how many have the back cut below the gob?

I'd hazard a guess at non or very little

[josharb87]

Have a look at 'rate my hinge' thread. 1082 posts how many have the back cut below the gob?

I'd hazard a guess at non or very little

 

Could just be that any deviation from the uk taught felling technique with a photographically perfect hinge is "wrong" and will be slated by armchair arbs so not worth the bother of posting any such deviation and the ball ache of trying to explain to brick walls isn't worth the hassle

[JLA Arborists]

Could just be that any deviation from the uk taught felling technique with a photographically perfect hinge is "wrong" and will be slated by armchair arbs so not worth the bother of posting any such deviation and the ball ache of trying to explain to brick walls isn't worth the hassle

 

 

True and a fair point

[Wood-be]

Personally I always go level or above. I recon, if you cut below the gob then if it hangs up when felling there could be the potential it could skid off the stump backwards and do damage. If you cut above then you are making a physical step for the stem to jump up! Before it can skid backwards.

 

Sent from my C6903 using Tapatalk

[Jimbo 76]

The simple answer is the back cut should never be below the apex of the gob.

 

I have offen seen people angle down the back cut towards the gob assuming this will help mechanical advantage in driving wedges etc. This is a massive misnomer. It takes a surprising small amount of holding wood to safely fell a tree. By slanting your back cut you simply decrease the efficiency of the wedges as the largest turning motion is given at 90 to the hinge. I know this sounds counter intuitive but it's the case.

 

Good placement and correlation of the back cut to hinge becomes more apparent the larger the tree.

 

If your doing anything over 1.5m you simply won't be able to fell the tree with wedges if your back cut is below the hinge. The mechanical disadvantage will be become apparent.

 

If you don't believe me try it. I've ballsed it up in the past and it's not fun.

 

Cheers,

James.

[Stephen Blair]

What if you don't want to use wedges, you want to use momentum rather than faff about lugging them to a job, so you do half and half, get it going then slow it down by coming below so the hinge doesn't tear out due to side weight?

What if you want to do the back cut, get as far out the way as possible due to its location, say on a cliff edge then pull it over and you want it to go over as slowly as possible so not to damage say a Golf Tee?

[Stephen Blair]