Best hinge wood

[northmanlogging]

Please excuse the dumb question but how does the type of face change the hinge behaviour? Is one closing before the other?

Conventional face, the stem tends to stay on top of the stump longer, allowing the hold wood to bend much farther. Or in the case of a shallow conventional face, it closes up and the stem tries to lift off the stump, pulling fiber or worse back slipping.

Humboldt the stem slips off the front side almost as soon as the face closes, shearing the hold wood in the process

 

[catbuster]

Adding to that, a gapped face holds the front of the hinge wood in compression for a long time and when the face closes the butt kicks off the stump hard and it very quickly severs the holding wood.

A sizweel (sizwel? Sizwheel? Hopefully you know what it is, I’ve seen it spelled several ways) on a Humbolt or gapped face loads a whole bunch of wood and pulls harder than the rest of the hinge, much more than varying the amount of hinge wood side to side. I don’t use it much, and when I do it’s pretty much always on softwoods with long fibers or maybe very straight hardwoods with small crowns. It’s not something to try to swing trees far with but it can help overcome some side lean.

Open faces hold the hinge for a long time, broadly on back leaners to keep the hinge intact so the hinge won’t break, unlike with a small conventional undercut, as the tree goes vertical and then control is lost from the face closing/breaking the hinge and stuff is smushed.

So ultimately, yes, undercut construction has a lot to do with how the hinge wood behaves when falling a tree.

 

[KiwiBro]

Thanks fellas. I was thinking only in terms of setting direction and not considering much else. Glad I asked and grateful for the answers.

 

[madhatte]

It's also important how the stem breaks from the stump and all that. A Humboldt breaks the top last, versus a Saginaw breaking the top first. A snipe splits the difference sort of by putting a bunch of the kinetic energy out in the horizontal. As a fire/forestry guy I don't care much about saving BF but I do care about where the stem goes and how far I can be from it when it hits the ground. If my escape route is uphill you better believe I'm gonna put that stem as far downhill as possible.

 

[KiwiBro]

It's also important how the stem breaks from the stump and all that. A Humboldt breaks the top last, versus a Saginaw breaking the top first. A snipe splits the difference sort of by putting a bunch of the kinetic energy out in the horizontal. As a fire/forestry guy I don't care much about saving BF but I do care about where the stem goes and how far I can be from it when it hits the ground. If my escape route is uphill you better believe I'm gonna put that stem as far downhill as possible.

Thank you. I lost a good one backwards last Summer. Tall enough to span the whole gulley. I watched as the top hit the far side and the very strong but brittle stem flexed way beyond its limits. Left stress fractures throughout when I tried to mill it. About a $3k stuff up, maybe more. :-(

 

[Bwildered]

Please excuse the dumb question but how does the type of face change the hinge behaviour? Is one closing before the other?

I don't believe it does between the two scarf cuts being discussed, now the height of the backcut changes everything .

 

[northmanlogging]

I don't believe it does between the two scarf cuts being discussed, now the height of the backcut changes everything .

ya know, I can't tell some times if your just poking sticks at the bears, or legitimately full of ****.

 

[Bwildered]

ya know, I can't tell some times if your just poking sticks at the bears, or legitimately full of ****.

Just think about it, in the falling direction the fibres have been cut by the scarf, it is irrelevant whether the scarf is above or below the level cut, the back cut influences how the fires break, if the backcut is at the same level as the scarf level cut the fibres shear cleaner, which means they don't hang on longer, when the backcut is higher or lower than the scarf level cut , the fibres left on the stump or log tend to be longer & pull out more which means they hold for longer,

 

[rwoods]

Adding to that, a gapped face holds the front of the hinge wood in compression for a long time and when the face closes the butt kicks off the stump hard and it very quickly severs the holding wood.
... .

I am not sure I know what you mean by a gapped face. Are you talking about a face where the upper and lower cuts don’t meet at a point but rather meet respectively at upper and lower edges of a vertical cut? I believe some refer to this cut as the original Humboldt or old growth Humboldt. Or are you talking about something different?

Ron

 

[catbuster]

I am not sure I know what you mean by a gapped face. Are you talking about a face where the upper and lower cuts don’t meet at a point but rather meet respectively at upper and lower edges of a vertical cut? I believe some refer to this cut as the original Humboldt or old growth Humboldt. Or are you talking about something different?

Ron

That’s what I’m talking about. Some people call it a gapped cut to not confuse the two Humboldt cuts, seeing as what’s commonly referred to as a Humboldt undercut is technically a modified original Humboldt that achieves mostly the same purpose with less cutting.

 

[rwoods]

Thanks. Ron

 

[Woody912]

would anyone put shagbark hickory near the top of their list?

purty certain Logger Wade would put it near the top of his bad list. Hackberry might hold a hinge as well as anything, had one stop at a 45 degree one time, did not put a wide enough face in it.

 

[northmanlogging]

Just think about it, in the falling direction the fibres have been cut by the scarf, it is irrelevant whether the scarf is above or below the level cut, the back cut influences how the fires break, if the backcut is at the same level as the scarf level cut the fibres shear cleaner, which means they don't hang on longer, when the backcut is higher or lower than the scarf level cut , the fibres left on the stump or log tend to be longer & pull out more which means they hold for longer,

uh... no...

hold wood, and face opening have far more to do with how much fiber bull than the back cut height.

 

[northmanlogging]

Granted a flush back cut does increase your chances of no fiber pull, it still has more to do with the hold wood.

as for low or high, both pull wood

 

[woodfarmer]

I’m not seeing this gapped cut? A humboldt is an upside down open face cut, so how does a gapped cut look?

 

[rwoods]

I’m not seeing this gapped cut? A humboldt is an upside down open face cut, so how does a gapped cut look?

Ron

 

[catbuster]

As much as I dislike that man’s presentation, that’s spot on. There’s another video that’s much more recent from some younger guys up in Washington that go over all sorts of undercuts in a much more coherent fashion. I’ll see of I can find it and I’ll link it up here later, when I get back home. If I was in the woods with a saw today I’d probably just lay a couple trees out with each undercut.

 

[RandyMac]

 

[catbuster]

Alright, it isn’t a great tree felling tutorial as the title would have you believe, it leaves a lot out. What it is... Is a great go over for faces/undercuts, what they do and how they work.

Guys go over undercuts.

 

[TheDarkLordChinChin]