This 40 watt laser shotgun somehow isn't illegal to build

Shawn Knight

Posts: 12,186   +120
Staff member

Late last year, we shared a story of a gadget enthusiast that built a fully functional laser watch. While impressively cool, the invention pales in comparison to this laser shotgun that YouTuber “styropyro” recently put together.

The 40 watt gun is comprised of a blue laser diode array that shoots eight parallel five watt beams. It’s strapped to a massive passive heatsink, is powered by a lithium polymer (LiPo) battery pack and is regulated by 24 LM317 drivers.

As styropyro points out, dangerous is an understatement. Watch as he ignites all sorts of objects with ease. Very cool!

Found is a TechSpot feature where we share clever, funny or otherwise interesting stuff from around the web.

Permalink to story.

 

VitalyT

Posts: 4,915   +3,703
TechSpot Elite
This 40 watt laser shotgun somehow isn't illegal to build
Same policy as having a bottle of booze in the car, which is fine for as long as it remains unopened.

Just so, before Hiroshima, it was perfectly legal to have an atomic bomb in your household ;)
 

trparky

Posts: 706   +599
I like this comment on the video...
"Do you want Supervillains? Cause this is how you get Supervillains!"
 

lipe123

Posts: 894   +453
Meh unless you actually point it right into someones eye its fairly harmless, it takes quite a while to warm up something to dangerous levels so moving targets would be totally safe.

It does look pretty cool though, wish he cleaned up the messy wire job better
 

Seventh Reign

Posts: 131   +65
Meh unless you actually point it right into someones eye its fairly harmless, it takes quite a while to warm up something to dangerous levels so moving targets would be totally safe.

It does look pretty cool though, wish he cleaned up the messy wire job better
You obviously didnt actually watch the video. Ignition was virtually instantaneous. With the correct focal length, even a moving (human) target would not be able to get out of the way in time.
 
G

Guest

Everything he does in that video can be done with a match. I guess that's why a laser of that power is not illegal.
 

lipe123

Posts: 894   +453
Meh unless you actually point it right into someones eye its fairly harmless, it takes quite a while to warm up something to dangerous levels so moving targets would be totally safe.

It does look pretty cool though, wish he cleaned up the messy wire job better
You obviously didnt actually watch the video. Ignition was virtually instantaneous. With the correct focal length, even a moving (human) target would not be able to get out of the way in time.
It took a full 1.5 to 2 seconds to pop an inflated balloon just 1-2 meters away. Anything beyond the perfect focal distance will take forever. A magnifying glass in the sun is every bit as powerful as that laser by comparison.
Saying dumb things like "you obviously didn't watch the video" is just silly don't do it. The only reason that laser is any good is because of the focusing lens on it which limits its use to very short distances and perfectly still targets.
 

wiyosaya

Posts: 5,121   +3,208
So a "secret" or two without saying much:

If each beam is collimated to a fairly small spot size, each beam by itself is enough to start a fire depending on the target material and at a reasonable distance since laser light does not spread significantly when collimated.

This is not a 40-watt shotgun. It is an 8 x 5-watt array. For it to be a 40-watt shotgun, the beams would require phase conjugation which is what the recent military laser uses to produce a 30kWatt beam from multiple, lower power fibers. In this "shotgun" each beam is probably partly cancelling out the power of each other beam since the array is not phase conjugated. Phase conjugation is generally not within the economic reach of someone like this guy.

Nevertheless, it might be some dolt like this guy who ends up making it illegal for the basement experimenter to build something like this - especially in the climate of this day and age. I am sure he thinks it is cool, but is he doing anything even remotely useful or scientific in nature with this? I highly doubt it.
 
  • Like
Reactions: Sancticide

MilwaukeeMike

Posts: 3,211   +1,455
Everything he does in that video can be done with a match. I guess that's why a laser of that power is not illegal.
The headline is just clickbait. It's legal to build a full-sized medieval trebuchet... it's legal to buy a flame thrower for burning out weeds, it's legal to buy fertilizer that can blow up a building.... and on and on...

The 40 watt gun is comprised of a blue laser diode array that shoots eight parallel five watt beams. It’s strapped to a massive passive heatsink, is powered by a lithium polymer (LiPo) battery pack and is regulated by 24 LM317 drivers.
Like anyone knows what any of that means.

What even cooler than setting paper on fire? This laser casts it's own shadow! Although I guess that's proof of it's wasted power. If all the light were focused forward, it'd be even stronger.
 
  • Like
Reactions: Sancticide

Capaill

Posts: 1,187   +723
I thought it wasn't possible to see the beam from a laser (sorry Star Wars fans). I guess he has a filter on the camera?
 
G

Guest

Why is everything that "might" be suspected of becoming a weapon need to be made illegal? Should Fists be made illegal? Will we all be forced to wear Socker Boppers over our hands in public so cowards will feel safe? Taglines like this article that pander to the fearful and eternal victims are a disgrace.
 
  • Like
Reactions: Sancticide

wiyosaya

Posts: 5,121   +3,208
I thought it wasn't possible to see the beam from a laser (sorry Star Wars fans). I guess he has a filter on the camera?
I was thinking that myself. What is likely happening is that the oxygen (or another gas) in the air itself is fluorescing as you can see the beam in blue and green lasers on other youtube videos.