Building new RGB indoor scanner for beam shows

[White-Light]

Consider also, that if you want to be crowd scanning, you WILL need to know how powerful your lasers are, so you will need to own, or have access to a power meter.
You will also need to understand how to calculate emissions in the crowd. You ask the question 'how powerful do myu lasers have to be to crowd scan' but in this case its how weak do they need to be. Don't forget to budget for a decent scanfail device, which I believe is a requirement in your country (and most others) for crowdscanning.

I will second this.

I just got my new laser tonight, 2.1 W.

Put out a full power white test beam across the room (about 10 feet) onto a cardboard box as I thought make a nice non reflective surface. Only ever intended to keep it on for a sec or two (as aware of the dangers of heating) but even that was too long.

In less than 1 second I had the cardboard box smouldering and on fire!!!

Very very sobering.

[steve-o]

I've found that scanning right above the crowd's head is just as amazing and appealing as scanning into the crowd (audience) . Plus you don't have to worry about permanently blinding someone.
If you are going to mount your laser modules and galvos in an old computer case as stated, you will need a thick aluminum plate to mount them to. Otherwise, component alignments will be unstable and the beams will not be aligned properly.

[TsevenT]

That is a lot of advice about safety! First of, math is not a problem so hit me with some numbers, equations whatsoever and I'm pretty sure I'll come to a safe setup. But I do have a question in general then. Where do all of you people use your scanners for, if it is not for scanning during parties or events? The main purpose of my build is to simulate to a little extent the shows done on big events. A small room with some loud music and a single laser doing a decent beamshow should be the main ingredients for future parties.

The last thing I want to create is an unsafe environment for myself and others. Setting stuff on fire with a beam of light is something I most of all would want to prevent from happening too.
Then a little thing about the definition 'crowd-scanning'. Steve-O pointed out that scanning overhead is just as awesome, but that is in fact what I would want to do. Literately scanning into the audience is not the idea. Are we all on the same wavelength about this term then?

What type of laser is still visible in a dark room doing a beamshow (just for the sake to get to know what order of magnitude we´re talking here, safety ignored). Is for instance a 100mW 532nm doing a widespread tunnel or some sort of wave still visible? And if so, how little power is needed to still be visible doing an intense beamshow? I hear people talk about 5W+ lasers being able to produce every color crisp clear and visible from the moon, but that seems a little over the top for my use.

[jooopy]

Somehow going with the cheap route such as $70galvos and crowd scanning just don't fit in my head. Using the cheapest materials to perform the most dangerous act of lasers just sounds wrong. A beginner wanting to crowd scan makes me feel a bit squeamish I must say. WTH is squeamish? I not sure but I'm feeling it bro. We got peoples here who have been doing laser shows for years and still NEVER crowd scan and that's with the more pro type hard-wares. Screw the math. Let's be considerate of the people. The crowd as we are calling 'em usually don't even have a clue. Drinking and dancing is what they came for but how many will end up permanently vision impaired. Let's figure that math. Love laser....GREAT ...me too... build and learn. Practice your archery you before start shooting apples off of the audiences heads. I'm here most days along with many many other sites learning and learning and learning. Got a couple years of learning under my belt but not even considering the danger you dream of. Please reconsider your dreams of crowd scanning. Throw down a few years of awesome beam-shows and learn. Like a kid in the archery shop who saw someone shoot the apple off an others head. It looked cool. Hmmm... wood string apple...oooops! We are here to help each other learn though.

[White-Light]

That is a lot of advice about safety! First of, math is not a problem so hit me with some numbers, equations whatsoever and I'm pretty sure I'll come to a safe setup. But I do have a question in general then. Where do all of you people use your scanners for, if it is not for scanning during parties or events? The main purpose of my build is to simulate to a little extent the shows done on big events. A small room with some loud music and a single laser doing a decent beamshow should be the main ingredients for future parties.

The last thing I want to create is an unsafe environment for myself and others. Setting stuff on fire with a beam of light is something I most of all would want to prevent from happening too.
Then a little thing about the definition 'crowd-scanning'. Steve-O pointed out that scanning overhead is just as awesome, but that is in fact what I would want to do. Literately scanning into the audience is not the idea. Are we all on the same wavelength about this term then?

What type of laser is still visible in a dark room doing a beamshow (just for the sake to get to know what order of magnitude we´re talking here, safety ignored). Is for instance a 100mW 532nm doing a widespread tunnel or some sort of wave still visible? And if so, how little power is needed to still be visible doing an intense beamshow? I hear people talk about 5W+ lasers being able to produce every color crisp clear and visible from the moon, but that seems a little over the top for my use.

If you're going to be doing it commercially you need to go on a laser safety course.

[norty303]

Then a little thing about the definition 'crowd-scanning'. Steve-O pointed out that scanning overhead is just as awesome, but that is in fact what I would want to do. Literately scanning into the audience is not the idea. Are we all on the same wavelength about this term then?

Crowd scanning - the act of scanning laser beams into the crowd area so that they are within the beams of light.
Overhead beams - the act of scanning beams that do not come within 3 metres of the floor of any part of the venue where there may be public access.

[ShortyInCanada]

"Then a little thing about the definition 'crowd-scanning'. Steve-O pointed out that scanning overhead is just as awesome, but that is in fact what I would want to do. Literately scanning into the audience is not the idea. Are we all on the same wavelength about this term then?"
OK. So you are on the right track about keeping it safe for the crowd. That's good. As long as you have made sure that nobody will get exposed and even if there is a failure of the hardware that a beam doesn't end up directed into the audience or reflected into the audience then you are doing better than a lot of those "club" type scenes. As indicated, putting the beams just above the crowd in a haze is very "involving" for the audience.

"What type of laser is still visible in a dark room doing a beamshow "
This is a bit more tricky. It will depend on the color of the beam(s), the other light in the venue, the ammount of haze/fog and the actual distances through those conditions at the time.(and other factors too but lets not over complicate it.)
A 20mw 532nm beam may cut through everything easily in the dark. Add some red lighting that illuminates the haze/fog and the effect is lessened. If you have green light that illuminates the haze/fog then the effect will be even more reduced. But at the same time a nice red beam would show much more dramatically. So it depends on lots of things that change quite a bit throughout the time of your event.
As an operator of the equipment your job would be to monitor and adjust things as you go to keep control over those variables safely.
You seem to be thinking along the right paths though. I think it would definitely be to your advantage to get someone who already does that thing out for the first few times, as suggested, so you could look over their shoulder and learn about it all. Just be clear up front that you are planning to ask them lots of questions and want to know more so they can plan for it.
Have fun and be safe.

[hobbybob]

That will be my next problem, dealing with the possible addiction. But to confirm, Riya lite DAC + LSX software is the good (and affordable) way to?

HI TSevenT, there will be a laser meet, next weekend in Ilpendam.
BorgqueenX will be there, he has a working Riya setup and laser. You can always start and later buy some other dac's ?
I started with an Easylase, then upgraded to 1 FB3, then 2 and then the QM. You can do this in phases.

Also Edison (johan) will be there , he sells selfbuilt modules, so you can start. Although a budget of a 1000 euro's is not really much for an RGB projector and Dac.

You could also start with a good dac, and a single color only and then later upgrade this projector. For instance start with green, then add blue (can easily be built for around 200 euro's incl. driver) and last add red.

Look in the laser meet and greet subforum to read about the ilpendam meet to meet people their and exchange ideas, learn etc.
It will give you a headstart and there might even be a safety course by McCarrot, so you will be informed right and correctly and not having to find all the answers by yourself !
(And risk peoples eyesight by doing so...)

[edison]

With your budget i would start with blue, DT30 scanners and quickshow dac. I would go for a selfmade case. I can tell you all about it at the LEM Also talk to dimitri, and Michelrietveld. They have done their builds themselves with partially my components and lasermodules. A good blue with your budget is difficult but a self build blue with prism set would be less costly.
Just pack your bag for a great LEM and with lots of crazy laserpeople and then start from there

[Stoney3K]

Don't forget the mounts to stick the dichro mirrors (these guys) onto. The dichros are just pieces of glass which need to be aligned in the path of the lasers to work, if not, you're going to end up with a collection of beams or spots on the wall with different colours, not with a white beam.

You can use these units from O-like, but only if your alignment is absolutely perfect to begin with. The better choice is to use kinematic mounts or flexure mounts, available through Laserextreme (mccarrot) here, 20 euros each. Dave also stocks them regularly, but they may be slightly more expensive since Dave (Lasershow Parts) ships from Australia. Also found on eBay here (I'd be happy to take a few of 'em off your hands if you get a lot shipped to NL).

You will need at least 2 (one for each mirror), although 3 would be more useful since you can place the lasers in parallel and use the third mount for a bounce mirror, so each laser makes a 90 degree angle with the dichros. Most of the time, space is limited in the beam path along the dichros, so some angles may be required.

As for the lasers, 473nm blue is slightly brighter but more expensive. 445nm blue is dirt cheap but but takes more power to get a properly visible beam, so if you're scanning into an audience, be careful. 445nm is a lot more divergent than 473nm though, and you can use a lens to increase the laser's divergence if necessary.

If you're only using the laser for beam shows and not very demanding on graphics, a 20K or 30K entry level scanner system should be more than sufficient. SCANECO20 is a good kit to start, or DT20/DT30 kits if you want a little more performance in the future.

I'd suggest going with something simple like a RIYA DAC for the connection to your PC, as a sound card DAC may not be 100% reliable. But then again, Enschede is a technical university, so it may be a cool challenge to hack something up from scratch. ;-)