An interesting theory but the longer the distance between the hinge and the back of your back cut the LESS force your hinge will see in the event of a set back. It is true that an angled back cut will add a shearing force to the pulling force the hinge already sees which may be problematic.
Full Answer
Why do people use an angled back cut?
The main reason people tell me they use an angled back cut is to stop the tree from going backwards! As stated in the podcast and other in posts several times, it does not work and if sit back or total failure with the tree going opposite the face cut happens you are not doing your job.
Is it safe to cut a tree with an angled cut?
This is a dangerous practice which you will never see promoted as an acceptable method of felling trees (OSHA restricts its use) as it greatly reduces the effectiveness of the hinge. They are usually made by uninformed, beginning tree cutters who believe the angled cut will help prevent the tree from falling backward off the stump.”
How does the angle of the back cut affect the wedge?
Technically, the more of an angle you make on the back cut (provided that you meet the hinge properly), the more surface area there is between the hinge and the point at which the wedge makes contact.
What happens when an angle cut tree breaks off?
When an angle cut tree does break loose it will slide forward off the stump, and in most cases fall backwards as the base of the tree hits the ground. Figure 1: Angle vs. flat direction of force. Figure 2: With vs. cross grain breaking of wood. Figure 3: Angle cut tree falls backwards.
Why use a back cut?
Another advantage of using a back cut that is in line with the notch apex is that it is easier to avoid by-pass when forming the hinge, as your back cut line is in line with the notch apex. A raised back cut takes focus away from the notch apex.
What is the advantage of a back cut?
One safety advantage of a back cut that is more in line with the notch apex is that the operator’s chainsaw is less likely to be caught and pulled along with a falling tree. A raised back-cut, stepped up from the notch aperture can create a kerf in the section of the trunk that is falling.
How thick is a hinge cut?
A common rule of thumb for hinge wood thickness is 5- 10% of the tree’s diameter. This leaves a section of uncut wood left behind the initial bore cut.
When is it necessary to use wedges or pull lines?
All of this happens when the hinge wood is cut thin enough to begin bending or hinging and applies to forward leaning trees. When felling back leaning trees or trees that are otherwise loaded against the notch, it may be necessary to use wedges, jacks or pull lines to initiate the fall.
When does the hinge have to break?
In these cases, the hinge will have to break when the face notch closes. After all a notch with a 45 degree or less notch aperture will have to break the hinge and as a result will lose control when the tree in most cases is only half way to the ground.
How big of a tree can you cut with a bore cut?
This method is limited to larger trees and is generally not suitable for trees less than 6- 10 inches in diameter. With the bore-cut back cut technique, the cut begins behind the notch with the bar of the saw being bored through the center of the remaining holding wood.
What is an open face notch?
If the notch opening is 70 degrees or greater (called an Open Face Notch), the likelihood of hinge failure is greatly diminished and the risk of the tree sliding off the stump along with it. A simple advantage of an open face notch is that it gives the hinge the opportunity to work through the entire arc of the fall thereby giving a greater degree of control of the falling tree and improving faller safety. In some standards, this advantage also allows for back cuts made in conjunction with open face notches to be placed lower and in some cases in line with the notch apex. The reasons behind this relate directly to the inevitability of hinge failure and the many risks associated with this loss of control associated with notches with openings less than 45 degrees.
