Few years ago my Brother bought a 12" tree shear. We used it quite a bit the first year. Then it mostly sat.
He tried to use it on his Kubota
L3240. Wayyyyy too slow. Also very dangerous. It had the ability to shear a tree that the tractor could not handle.
It had a jaw set about 30" above the shear jaws. When closing on a tree the upper arms closed first. This gripped the tree so you could control the fall. Then the lower cutter jaws closed. When opening after shearing the tree the lower cutter jaws opened first, then the upper arms. So if you needed to release a tree quickly you could not. So,,,,, if sheared tree starts falling to the side you had the risk of tipping the tractor over on it's side before you could let go!!!! I used it some on my Kubota M9540 and it was much faster and a BUNCH more stable.
Then my Brother bought a Bobcat T300 CTL. That's when the tree shear shined!!!! Very fast. Would hold the cut tree so you could pile them. Much more stable when carrying a large tree. Definitely where a shear needs to be used.
End result, and my opinion. You have to use a shear with the end result in mind. If the end result is simply to clear some trees to open up an area for livestock grazing or something similar, a Shear is great. If the end result is to use the cleared area for anything more productive or to keep it clear with a brush cutter, then the Shear isn't such a great idea. You end up with an area littered with stumps. You can't shear below ground level. And once you kill the trees in the area and their roots shrink you will find the stumps are sticking up out of the ground.....
Anxious to see what you come up with, especially if you build one!!! I'll try to find a pic of the brand my Brother had.
