flushcut
TreeHouser
Howdy Sappy1!
High Back Cut, Burnham Style!
- Thread starter Burnham
- Start date
- Replies 329
- Views 58K
SouthSoundTree
Treehouser
Hi there Sappy1. Welcome.
jefflovstrom@sb
TreeHouser
You did it Mike!
jefflovstrom@sb
TreeHouser
Hey Mike, Glad you posted! Now keep it up! Ha!
R
Ridgey
Guest
MasterBlaster
Administrator Emeritus
AWESOME shot!!! 
B
bill22
Guest
Nicely done.
MasterBlaster
Administrator Emeritus
This thread has been sanitized.
SeanKroll
Treehouser
What is the thought on how a high back-cut can sap the effects of wedging? Is it the energy that is required to split the vertical grain of the hinge?
SkwerI
Treehouser
Absolutely.
murphy4trees
TreeHouser
of course, which can be A LOT and often then ends up in the back cut being over-cut and as soon as it bypasses the notch the weight of the tree crushed the no-existent hinge and sits on the bar and traps it.
Marc-Antoine
TreeHouser
I don't think that the force involved in splitting the vertical grain represents a major part of the whole, beside the folding force of the hinge and the leveraged force of lifting the tree. It seems secondary to me, excepted if the stump is a fiber's mess. But I agree with the risk of overcutting if one cuts until the tree falls alone or if the grain is twisted.
The main difference between a low and a hight back cut (for me) is the actual pushing force of the wedge:
- With a level backcut, the almost vertical force of the wedge is somewhat perpendicular to the plan between the back side and the hinge. That's the most favorable way to push, like a perpendicular rope is for pulling. So, the trunk rotates around the hinge with the less input.
- With a hight backcut, the wedge pushes vertically the same way, but the hinge is way bellow. The back side - hinge plan is now at a very significant angle from the previous one and the efficiency of the push is reduced. It's the same effect in pulling a tree from the ground with an angled rope.
The loss of force in rotating the trunk is redirected to stretching vertically the hinge, increasing the risk of busting the fibers and losing the tree.
The main difference between a low and a hight back cut (for me) is the actual pushing force of the wedge:
- With a level backcut, the almost vertical force of the wedge is somewhat perpendicular to the plan between the back side and the hinge. That's the most favorable way to push, like a perpendicular rope is for pulling. So, the trunk rotates around the hinge with the less input.
- With a hight backcut, the wedge pushes vertically the same way, but the hinge is way bellow. The back side - hinge plan is now at a very significant angle from the previous one and the efficiency of the push is reduced. It's the same effect in pulling a tree from the ground with an angled rope.
The loss of force in rotating the trunk is redirected to stretching vertically the hinge, increasing the risk of busting the fibers and losing the tree.
I must say, I have never noticed any difference in the force needed whether the back cut is low or high.
There probably is some, but as a percentage of the total power needed to lift the tree, I think it is negligible.
There probably is some, but as a percentage of the total power needed to lift the tree, I think it is negligible.
SeanKroll
Treehouser
When I'm in doubt about a hinge's reliability compared to what I'm asking of it, I cut the bark off. Its good to see if the wood is bending at the hinge or splitting down the stump (never noticed it splitting up the hinge) when wedging.
MasterBlaster
Administrator Emeritus
And, once again.
Jed
TreeHouser
I vehemently disagree, Stig. Case in point?... today's job. The City of Bellevue hired me to fall a Cottonwood that the first faller apparently couldn't handle. Here's his ATTEMPTED stump...
He's obviously a West Coast beaver as exibited by his very low Humboldt; but just LOOK at how high he put in his back cut! Fighting that beefy of a hinge, it's no wonder the little bugger just got tired and walked off the job.
In my opinion, for maximum wedge-lift efficiency, a back cut should end-up much closer to this...
squisher
THE CALM ONE!!!!
MasterBlaster
Administrator Emeritus
Jed
TreeHouser
Not all beavers have 064's. 
flushcut
TreeHouser
East coast beavers only have short bars.
Jed
TreeHouser
I know... that's weird.
Brock Mayo
TreeHouser
Just finished page 30 of this post. Took me quite a while, but I learned a lot! There's probably an existing post on the subject, but I was wondering if someone could explain how and why a low stump on certain species will produce root pull or fiber pull off the desired lay? Recently I had a port orford cedar spar stall when the face closed, and then rotated 10 to 20 degrees to one side as it slowly broke the hinge wood. It might have had a hidden knot, but the hinge was pretty darn straight and even. I figured it was just the low stump and maybe the stalled hinge break? Any tricks or things to look for when cutting low to the ground?
