I seemed to read in Burnham's thread reference that you net gain by shifting hinge location towards the back. There was reference to 5 or 10 degrees as maximum trunk lean angle to tackle.
On a 50 foot tree at 5 degrees the top is over center by 0.087 x 50 = 4.3 feet. Placing the CofG at less than half height due to trunk taper, 20 feet x 0.087 = 1.7 feet. If the trunk diameter was 3.4 feet at the base the CofG would be right on the edge. A 50 ft tree might more likely have a 2 foot diameter trunk at its base so its CofG weight would all be overhanging. At 10 degrees it would be 3.4 feet offset, so really overhanging.
So shifting the offset to the CofG by a few or 6" is quite less significant as a proportion of 1.7 or 3.4 feet, vs shifting 6" in the realm of half trunk diameter (1 ft) where it could cause a 30% lessening of hinge fiber tension as a loose approximation on a 2 ft diameter at base trunk.
If these number aren't messed up, they suggest you gain more from lessening your chance of tension snapping the hinge while wedging. It seems to come from operating as a (smaller) proportion of CofG shift vs operating as a (larger) proportion of trunk base diameter.
Allowing for loose accuracy I think the math is generally right.
? Any thoughts or observations or corrections?
