This is a tree-cutting saw where the you have a chain that will saw wood. You wrap it around a tree. Then, there is a mechanical device that holds the chain, and runs it around the tree. You can also tighten the chain as it cuts into the tree.
As the saw gets tighter and tighter, the tree gets closer to falling. As to how to finish the cutting without the tree falling on you, I haven't figured this part out yet. Perhaps after a certain point you just whip out a regular chain saw, with the hoop saw having done most of the work.-- lawpoop, Oct 19 2008 Hoop Handsaw http://www.sprmarin...ath=3&products_id=6The manual version. [mylodon, Oct 19 2008] Directional falling https://www.youtube...watch?v=TN0bMU3hOzY [mylodon, Nov 21 2017] //As to how to finish the cutting without the tree falling on you// just tighten the hoop around the tree, start the saw and walk(/run) away.-- FlyingToaster, Oct 19 2008 As the saw gets tighter and tighter, you will become more and more motivated to figure out the final part. With sufficient motivation, you will succeed!
(or else someone will find your squashed body and start thinking philosophically about whether your final scream actually made any sound, with no one to hear...)-- lurch, Oct 19 2008 I think [lurch] is on to something :) Go make it, [lawpoop].-- phundug, Oct 19 2008 OK, I;m on it. Will report back at 0-2200 hours.-- lawpoop, Oct 19 2008 I used to think that this was a great idea but experience with chainsaws has turned me against it. First of all we have the problem of pinching which is inevitable with any straight cut that goes all the way through. Second problem, the saw is pulling the chain in a circle thus as the load on the saw increases the saw tends to move strongly to the side that it is pulling in which could be very exciting (especially in view of the first problem). And then, if the system fails we now have a half cut tree (danger!) with a saw jammed in it and no intuitive way to drop the tree. The idea of setting up a loop, anchoring to another tree and walking safely away has appeal, but I just don't see how it could be made to work.-- WcW, Oct 19 2008 I don't know if i should bun, for sharing an idea that i loved and lost, or give a bitter bone because I had a real love for this idea at one point.-- WcW, Oct 19 2008 You can do this by hand with a wire saw so it would work for a mechanical one if you were to cut the same wedge shape out first, but I'd still prefer a chain saw. (+)-- 2 fries shy of a happy meal, Oct 19 2008 how do you mechanize a wire saw? reciprocation?-- WcW, Oct 19 2008 Or a continuous loop...as long as you stop cutting before the tree binds your wire tight and rips the saw from your hands.-- 2 fries shy of a happy meal, Oct 19 2008 problem is getting traction on a wire without dulling it.-- WcW, Oct 19 2008 Aw heck, just cut 'em down with lasers!-- lawpoop, Oct 19 2008 //problem is getting traction on a wire without dulling it// Not so!
Some traction configurations, will also *sharpen* the teeth. They are just not energy ineffecient. But if we are hacking wood, I doubt we are concerning ourselves with efficiencies.
{edit} in fact the most traction you could ever get requires that you sharpen the teeth of the "belt"/ medium.-- 4whom, Oct 19 2008 Cordtex.-- 8th of 7, Oct 19 2008 strong strong reservations about that.-- WcW, Oct 21 2008 Heh. The hoop handsaw link reminds me that I had a hand-held flexible-wire saw long ago. It was supposed to be a survival tool. It did not work as advertised, not even when used with a flexed branch as a "frame" to keep it straight.
The idea as proposed has a fundamental flaw--it will jam up. If it were ever working, somehow, and hit the slightest obstacle, anywhere, the chain would tighten up and constrict into the tree. Which would make the teeth dig in harder, slowing and tightening it further. Et cetera, asymptotically.
If something were added to prevent digging in, such as little wheels in the chain, it might work, maybe. Without that, though, it crashes to the ground.-- baconbrain, Oct 21 2008 How do you keep the chain in the track?
Oh. Okay. There's no track.-- nomocrow, Oct 21 2008 Ok, I've got it.You attach the saw itself to another tree, a few feet higher than the one you want to cut, on a bungee cord/ratchet-strap system.That way the trunk will snap before the wire can pinch and the direction of fall will already be determined from the slant of the cut.Since the tree will fall away before the cut is finished it gives the operator the time needed to shut it down before the wire comes flying out of the cut under tension.-- 2 fries shy of a happy meal, Nov 21 2017 random, halfbakery