This is a big laser.
[3ric] from Hackerbot Labs gave me a run down of their BattleYurt laser installation at Toorcamp. It’s built with twenty-four 1 Watt lasers taken from a Casio DLP projector. The laser is housed on top of a yurt, which contains the controls and cooling system. It was built with the goal of measuring diffuse reflections of the atmosphere, but it also does the job of looking awesome when fired into the sky.
Since pointing lasers at planes is a bad idea (and very illegal), the Hackerbot Labs folks got clearance from the FAA through FAA AC70-1 to ensure airspace would be clear during Toorcamp. ANSI Z136 standards were followed to keep everyone safe. There were four emergency stops around the yurt, and motion sensors to ensure nobody entered the enclosure during operation. Tilt and thermal states were monitored to disable the system if it overheated or toppled over.
The cooling system consists of a custom heatsink and an array of Peltier devices that prevent the diodes from burning up. The whole thing is controlled by an Arduino, which cuts power to the laser if any of the safeties are tripped. The system was very well thought out, and they’ve posted details on the regulatory and safety aspects of the project.
Hackerbot Labs even added a Morse Code feature that sent out limericks during the camp. While many people had lasers at Toorcamp, Hackerbot Labs can take pride having the biggest, most powerful one.
[image 3ricj]
This is a “Big laser pointer” xD
Pretty epic laser Hackerbot Labs, props!
– Dad! I see alien beam coming down from the sky, is it the invasion?
– Relax, son. It’s just those nerds from hackerbot toying with their new lazor. Now get back to your homework!
now i have these urges again….. Must build deathray!
/Lamer
The whole thing is controlled by an Arduino
That’s a little unnerving :-P
People seem to be confused, so allow me to elaborate.
The whole thing is controlled by an Arduino. AN Arduino. One. Uno (an Arduino Uno, to be exact ;-) )
There’s no redundancy in this system. What happens if the arduino fails? (Catastrophically, or in a creative way, such as the loss of a single pin). Powering your standard hobbyist 3D printer with an arduino is one thing, but when you get into powerful machinery (for which 24W of laser diodes reasonably applies) and/or public displays, explaining that you’re running your equipment off of one arduino does not bring one a great deal of comfort, sorry.
“Arduino Uno, to be exact”;
I’m not sure where you got that information as we have not had a chance to publish our schematic yet; we did some prototyping on the uno, but the final configuration used a pro-mini. All this being said, the system did have several internal safety interlocks, specifically if the drivers loose signal it shuts down, and the signal must be driven in order to turn on.
The point is that there is a dedicated microprocessor which provides interlocks. It does not require a desktop OS or anything like this to run. While a pro-mini might seem strange for this application, could you cite any reason why a different microprocessor would work better?
The funny thing about publishing information about lasers online is that there are lots of armchair safety wizards who can share useful information. There are also safety trolls, who are really worried about people hurting themselves. :)
I would consider myself an “Armchair Safety Wizard” here. I would safely stay away from this construct sitting comfortably in my armchair, while the wizards who built the damn thing ran the show. With or without an Ardunio.
Uno: Spanish for one.
Uno: A microcontroller development board developed, sold, and marketed by Arduino.
Because comedy.
As someone who helps design and test commercial aircraft flight control systems (which need, and have, excellent redundancy) for a living and was also tangentially involved in the product, it is my judgement that redundancy would be inappropriate for this project. There are a few reasons:
1) The total hazard exposure time was low, perhaps a dozen hours. Since the probability of a hazardous failure grows with time, a short exposure time reduces the overall risk.
2) Modern semiconductors, to a second or third approximation, fail because of system design and interconnect issues. While that second or third order isn’t good enough for my day job, it does mean that you can reasonably neglect such failures for the purposes of risk analysis of a project like this awesome laser. This means that virtually all possible failures are design or construction errors, not random failures… and redundancy can only protect you against random failures.
3) Redundancy theater is easy, while real redundancy is extremely hard. It turns out to be exceptionally easy to build a ‘redundant’ system that just creates a new and different single point failure. Now, that can be an appropriate solution, if and only if the new single point failure is one that you are aware of and is much, much more reliable than where you moved it from. But it’s much easier to just delude yourself into thinking you’ve built a redundant system, and self-delusion is the mother of all engineering failures.
In computer science, this problem goes by the name of the Byzantine Generals problem… and it’s a thoroughly knotty one. There are a couple of canonical solutions, but they’re very complicated to implement in practice and require extensive testing to validate. I should know — I make a pretty good living doing exactly that.
4) Complexity is also the enemy of reliability (and therefore safety). Every additional quanta of complexity increases the probability that the designers and builders will make a design or construction error. A system should have the minimum complexity required to attain its goals given its constraints, and I’d say that this laser system does pretty well at achieving that.
5) Redundancy hugely increase complexity, and it can only protect you against truly random failures. It *CANNOT* protect you against design or construction errors; in fact, it makes them *MORE* likely by increasing system complexity.
Therefore, I think attempting to add redundancy to this system would have made it less safe or prevented it from happening at all.
^This wins for being the most informative comment I’ve read on HaD to date.
I agree, Most excellent post!
@Pierce Nichols:
Great post. Let’s hope this keeps the “safety trolls” quiet now.
We controlled a 12kW laser using a PIC16F886….
” The whole thing is controlled by an Arduino ”
Gives me a warm feeling inside, to read that.
Go forth ‘Makers’ of Earth and do your thing.
:)
This need a video of the laser in action. i hope when it is in use no plan fly over and blind the piloot. can this beam hit ISS or is that way to high to hit it whit the beam its only 300km up
This color of laser likely wouldn’t make it out of the atmosphere with any “point” due to natural diversion from interaction with molecules. You’ll find these colors of lasers are extremely hard to focus over long distance within our atmosphere.
It was calculated to reach 20000 feet. If only planes could fly by to take pictures from above the clouds… CHECK FLICKR FOR “LASERCAMP”
lol didn’t read!
“… the Hackerbot Labs folks got clearance from the FAA through FAA AC70-1 to ensure airspace would be clear …”
Also, while it might be visible from the ISS, they would have to line up perfectly (so unlikely it’s not worth considering), and it would basically look like a very dim flashlight.
To all the haters, the best part:
“The whole thing is controlled by an Arduino…” ;)
IHMMA FIHRING MA L4Z0H!
Now that’s a pretty big n’ cool lazor. But Arduino?
>.<"
They are not just flashing LEDs. Care to explain why this is not a respectable use of one?
You seem to forget exactly what an arduino is.
I wonder how long it takes to light a match on fire
I wonder how long it takes to light a velociraptor on fire
I wonder how long it takes a velociraptor to light a match on fire.
I wonder how long it takes to fire velociraptor from a match.
The appropriate way to install safety on a setup like this avoids interpretation or processing. The first thing that comes to mind is mercury switches that cut the power when rotated. If there are signals that need to be interpreted, do it by using an astable system that operate in their unstable state and switch off (go in their stable state and stay there) when tripped.
It was built with the goal of measuring diffuse reflections of the atmosphere
Haha. I don’t trust this. It was built because you can and because it’s big f*cking laser of awesomnes. The official diffuse reflection “reason” has been added artificialy. :-)
umm, see that photo above? what do you suppose you are looking at? Oh wait… diffuse reflections of the atmosphere?
I didn’t find a mention of why you’re measuring diffuse reflections. Your build description focuses mainly on the how and not the why so it’s not unexpected that a bit of skepticism exists.
When it comes to most things, but especially lasers, “Because I can” is a perfectly good reason to build.
Toorcamp my eye. It’s a rebel base and they fired that laser to temporarily disable Imperial Star Destroyers orbiting around their escape path.
Agree. Look at the similarity between the picture and this:
http://www.youtube.com/watch?v=Wks4k5I0098
I’m not certain about the wisdom of pointing/sending ANY signals into space in any direction. I know, I know, TV and radio… but Coherent Light is another story.
It was done in black and white thru most of the 1950’s. The redhead race in space know.
I Love Lucy, it’s the standard of earth inteligence speeding out thru the universe.
Who made Star Trek? Desi-Lou Productions of course.
I’ve used lasers not pointers but a powerful one back in the 80’s to send out binary messages into space. last week a crop circle showed up in my back yard. I am not joking and am totally serious.
Try popping balloons with it yet? :P
Now to mount one on the back of one of the remaining killer whales. (HeHe)
To those wondering about matches, balloons, or otherwise burning things. Look up a video on Youtube of a single blue Casio DLP laser doing such things. There’s your answer.
Because 24 beams in parallel still have the same amount of power per beam. They are not combining the beams, or even tilting them to converge at a particular range. Only viewed at a distance does it look like a single, more powerful beam, because the eye can’t separate the scattering from individual beams.
I heard that crossing the streams would be very bad.
The fact that balloons and matches are finite objects that conduct heat makes the reality a bit more complex, but you’re mostly right.
sure, but it can have quite an effect on hackaday commenter sized objects. ;)
Is this hack a day or whine-a-day? They even got FAA approval! Ten times more safety than your average 20 mW laserpointer from China
Looks like Missile Command
can you point it in the sky towards due east tonight at midnight? Id like to freak some friends out. Muhahahahaha
I wonder if you could spot it in the sky if you would be just behind the horizon.. It must diffuse enough to leave a mark in the night sky..
lol “power RMS”
Musing aloud:
I have heard of people using laser beams to interact with the arcs from a highly energised tesla coil – the laser was used to stimulate or control the arcs in a certain way…
Would the project in the article be powerful enough to interact with lightning storms and stimulate lightning bolts in a controlled manner? Does it have enough wattage to set up ion pathways for the lightning to be attracted to?
Hmmmmm…?