Laser tree trimmer - GIF

**Frank S** · Apr 22, 2023, 09:18 PM

Originally Posted by bob_3000

It's the size of a big camcorder (pause at seven seconds) shoulder mount coming soon.

Then maybe I can up the power a bit, roof mount it on a gambol on top of one of my vehicles. Then the next time a Chinese spy (sorry, weather balloon) is spotted I can shoot it down without having to wait until it crosses the entire USA.

**IntheGroove** · Apr 22, 2023, 09:31 PM

I'm sure there are two lasers. One for spotting and one for the kill...

**nova_robotics** · Apr 22, 2023, 10:21 PM

Originally Posted by bob_3000

It's the size of a big camcorder (pause at seven seconds) shoulder mount coming soon.

That's just the head. That's a fibre laser (the thick cable coming out of the back is actually glass fibre). There's a gigantic multi-kilowatt laser source off screen that probably runs off of 240v three phase.

**hemmjo** · Apr 22, 2023, 11:00 PM

If you have ever seen a laser cutter working there is SMOKE. Cutting steel, wood, paper, plastic, leather, whatever, there is smoke, a LOT of smoke that must be removed from the work space.

There is a lot water content in a live tree all of that has to be vaporized before the wood burns. IF the laser was indeed powerful enough to cut the tree from that distance, vaporizing that much material in that short, 1-2 second, amount of time would result in a near explosion of the wood due to vaporizing all of the water content.

All of the laser cut edges I have seen are relatively smooth. If you look closely at the tree cuts, they look a lot like chainsaw cuts to me. Looks like someone used a torch to blacken the wood. They even held it too long in one spot in the photo and charred the wood too much.

Click photo to enlarge

Laser tree trimmer - GIF-laser-cut-1.png

You would think YouTube would be cluttered with videos of this if it were true. But there are only a few laser related videos there all of dubious validity.

As always, I am open to being shown real evidence, but I have not see any yet. Seeing is NOT believing these days!!!

**mr_gormsby** · Apr 22, 2023, 11:21 PM

The hard hats are for when they accidently shoot it directly overhead while indoors.

**mr_gormsby** · Apr 22, 2023, 11:22 PM

I figured it was from April 1st

Originally Posted by hemmjo

If you have ever seen a laser cutter working there is SMOKE. Cutting steel, wood, paper, plastic, leather, whatever, there is smoke, a LOT of smoke that must be removed from the work space.

There is a lot water content in a live tree all of that has to be vaporized before the wood burns. IF the laser was indeed powerful enough to cut the tree from that distance, vaporizing that much material in that short, 1-2 second, amount of time would result in a near explosion of the wood due to vaporizing all of the water content.

All of the laser cut edges I have seen are relatively smooth. If you look closely at the tree cuts, they look a lot like chainsaw cuts to me. Looks like someone used a torch to blacken the wood. They even held it too long in one spot in the photo and charred the wood too much.

Click photo to enlarge

Click image for larger version.

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You would think YouTube would be cluttered with videos of this if it were true. But there are only a few laser related videos there all of dubious validity.

As always, I am open to being shown real evidence, but I have not see any yet. Seeing is NOT believing these days!!!

**nova_robotics** · Apr 23, 2023, 12:37 AM

Originally Posted by hemmjo

If you have ever seen a laser cutter working there is SMOKE. Cutting steel, wood, paper, plastic, leather, whatever, there is smoke, a LOT of smoke that must be removed from the work space.

There is a lot water content in a live tree all of that has to be vaporized before the wood burns. IF the laser was indeed powerful enough to cut the tree from that distance, vaporizing that much material in that short, 1-2 second, amount of time would result in a near explosion of the wood due to vaporizing all of the water content.

I think you're right. And the small pan/tilt mount that's driven by what appears to be a NEMA23 stepper that's been painted silver. That's got 1.8 degrees per step with full stepping, maybe 0.1 degrees if they're really careful with the microstepping. Lets say the beam is 1mm in diameter (which in reality is probably much too large) then with a stepper that's accurate to 0.1 degrees the tree could only be a maximum of 1.1m away in order for the laser to make a continuous cut. Any further and the cut would be discontinuous as each step would move farther than one laser beam width and the tree wouldn't be cut. It would just be perforated like a piece of toilet paper.

If this was real and had any hope of cutting a tree at a distance of more than a couple meters you'd need a solid base with two big fat harmonic drives to aim the laser.

**Frank S** · Apr 23, 2023, 01:06 AM

Originally Posted by nova_robotics

I think you're right. And the small pan/tilt mount that's driven by what appears to be a NEMA23 stepper that's been painted silver. That's got 1.8 degrees per step with full stepping, maybe 0.1 degrees if they're really careful with the microstepping. Lets say the beam is 1mm in diameter (which in reality is probably much too large) then with a stepper that's accurate to 0.1 degrees the tree could only be a maximum of 1.1m away in order for the laser to make a continuous cut. Any further and the cut would be discontinuous as each step would move farther than one laser beam width and the tree wouldn't be cut. It would just be perforated like a piece of toilet paper.

If this was real and had any hope of cutting a tree at a distance of more than a couple meters you'd need a solid base with two big fat harmonic drives to aim the laser.

the old saying goes if it looks or sounds too good to be true then it probably isn't, but hey, it's on the internet so it must be true, right?
Still want to be able to poke holes in a gas balloon from 70,000 feet though. and I know none of my rifles can do it.

**schuylergrace** · Apr 23, 2023, 01:46 AM

The other thing I noticed was that the cuts seem to go straight across, but the "laser" is being aimed up at a pretty good angle from the ground. And that sample cross section they held up looked like it had been chainsawed (saw marks) and torched afterward.

**nova_robotics** · Apr 23, 2023, 02:58 AM

Originally Posted by Frank S

the old saying goes if it looks or sounds too good to be true then it probably isn't, but hey, it's on the internet so it must be true, right?
Still want to be able to poke holes in a gas balloon from 70,000 feet though. and I know none of my rifles can do it.

70,000 ft is a really big ask. The beam divergence on these types of lasers is generally quite bad. Most lasers really. The laser dot would probably spread out to be a few feet wide by the time you're a couple miles out, at which point it's delivering about the same amount of heat (per unit area) as the sun does on a nice day. If somebody aimed the laser at you and pulled the trigger it would feel kinda nice. If you're at 10+ miles the beam has diverged so much that it's basically nothing. I think some of the high end military stuff can pull it off though. Popping those balloons really is a difficult problem.