Found one. You can see where I haven't a nice line on the face cut for the hinge, and have undercut the far side of the hinge heaps. Also, on the near side of the butt, most of those kerf marks are when the bar was bouncing/kicking back when I was trying to plunge cut. I was cutting at about shoulder height on that side and couldn't get stable enough to get good pressure on the 'good' quadrant of the bar nose when plunging.
It was the first time I have used a bottle jack and I have tidied up my technique allot since then. If you have never used jacks for lift, I recommend you give it a try. I'm really surprised by how much lift I can get compared to bashing wedges. Still use wedges when using jacks, but more for holding or small lift and to back up the jacks in case they fail.
View attachment 502218
Most of the time I'm using jacks, it's because the tree is big and leaning the wrong way. As such, I often place the jack in first and take some load before cutting the face. I had one like that this morning. It also highlighted my need for a larger saw because the hinge was twice as long as the full length of my saw (from end of handle to end of 32" bar!). I would have needed about a 40"+ bar to get the cuts to connected when coming from both sides. I recall when I thought a 32" bar was big. It was woefully undersized this morning.
That's always a concerns for me when using jacks. I don't know enough to know how far might be too much for the hinges so generally leave 'em quite fat if there's heaps of lean to overcome, and a fairly shallow face too. But I don't really know what I'm doing so maybe I'm just doing it wrong. That said, I actually find pine here (mainly what you'd call Monterey Pine up there I think) has quite pliable fibres that hang on and are wonderful for swinging the trees rather than having to use jacks or really beating on wedges. That is, if there is room to swing them and no real hazards to worry about. I've achieved well over 90 degrees of swing with our pine, but because red gum fibres seem very brittle, my best is only about 20 degrees.
Sure does suck when the wood is too soft to rely on. When in doubt, I try to get a line up the tree to at least hold if not pull it over if I strike too much rot. This morning, I had that but had tried twice to get a line up there and failed both times and because there were no hazards, I went a head and dropped it anyway. Was lucky the 1/4 of the hinge wood that wasn't rotten was on the side of the hinge I needed it, and I found enough not-soft wood for the jack to press against.
Cool. Yes please. So often, it's hard to find the time for pictures. I wish I could take more but am always under the gun and focussed on not killing myself or worse, anyone/thing else.