Mr. Berkelhammer makes a valid point. An experienced arborist can make a cut witout getting his saw wedged, this is not a tool for the unexperienced. In fact removing the line tension might make breaking off the chunk of wood<I> <B>easier</B></I>.
Once the bottle jack was removed, there was no need for an elbow. Once the elbow was removed, there was no need for rotation. This allows for a straight, one piece design, which is simple and lighter than the first drawings.
My last drawing had a rotation point, but only to make the unit modular. It was my opinion that raising the device up the tree would be easier in sections, than all at once.
If you think about the weak points, the base of the boom will have the greatest loads then loads would slowly get lesser as you move up the boom. So ideally, the boom would be shaped like a fishing pole, wide at the base a tappering as you move up the boom.
I'm thinking square tubing boom, telescoping inside a square tube base. A few holes and a pin would make the boom length adjustable. By lowering the boom all the way, just before moving the device down for the next cut, would balence the device so it wouldn't be top heavy.
Comments?