Home brew RGB Projectors

Thought I'd start a new topic on this. I have more or less completed my fully solid state RGB projector. The basic components are:

- 2 MaXYZ 200mW 660nm diode lasers with analog modulation combined using a polarizing beam splitter cube
- 300mW 532nm green DPSS with analog modulation
- 250mW 473nm blue DPSS with analog modulation
- Cambridge 6215 scanners tuned for 30KPPS @ 60 degrees

My first build looked like this:

http://junktronix.com/rgb-rev-1.jpg

It worked OK despite having to use a 100mW ttl modulation green laser while waiting for the replacement for my dead Laser Quantum POS. I figured out that I was losing a lot of power in the dichros so I got some better filters and rearranged the layout:

http://junktronix.com/rgb-rev-2.jpg

I'm getting >95% throughput for all colors now. After tuning the Pangolin palette to get a nice balanced white, it looks really good

http://junktronix.com/color-test.jpg

It's hard to get good pictures or videos of a laser show, but re-playing all the Pangolin beam shows with full analog color instead of ttl green has been great fun. I am really happy I held out for analog modulation on all 3 lasers. If your software supports it (Pangolin does, Alphalite doesn't) it's totally worth it.

Beautiful :)

Absoutely Great!
Nice and compact!
Is that a 12" x 18" breadboard you have it mounted on?
What dichroic filters did you end up using?

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Originally Posted by maxvideo

Absoutely Great!
Nice and compact!
Is that a 12" x 18" breadboard you have it mounted on?
What dichroic filters did you end up using?

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Thanks :) Yes, it's all built on a 12 x 18 aluminum breadboard. It's 3/4" thick so kind of heavy, but it only took a couple of hours to completely rearrange and realign it this afternoon. The alignment is nearly perfect (if I do say so myself) with good beam position up close and 100 feet away. I used shims to get the lasers all exactly 3" above the table and perfectly parallel to the table and the rest was pretty easy.

The blue+green combiner is something I pulled from some random surplus equipment. I wish I could get another because it's giving me about 98% throughput on both colors. The red+green/blue I got from Bob Ash @ New Method Lasers a couple of years ago. Oddly, it looks almost clear, but reflects about 98% of the red and passes about 96% of the green+blue.

Next I'll be designing an airtight enclosure so i can take it to Burning Man without destroying it.

:shock: I have noticed that when the focus is changed on these red units,the beam will have to be re-aligned. Just wondered if you have had the same thing happen with your set. I am going to do some re-arranging with my table. They are very nice with the analog modulation! What is your total output power as pictured? By the way nice setup!

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Originally Posted by MechEng3

:shock: I have noticed that when the focus is changed on these red units,the beam will have to be re-aligned. Just wondered if you have had the same thing happen with your set. I am going to do some re-arranging with my table. They are very nice with the analog modulation! What is your total output power as pictured? By the way nice setup!

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I have not had to mess with the focus so have not seen this problem. If the focus is loose, you can use a small piece of teflon tape (the stuff you use to seal pipe fittings - a buck a roll at the local hardware store) to stiffen it up.

This setup has a bit over 400mW of red, about 250mW of blue and 300mW of green so nearly a watt when everything's going full blast. It takes less than 100mW of green to get a nicely balanced white though so unless I'm doing long distance outdoor stuff, it'll be more like 750mW. What really matters is that In a dark room with some fog it is stunningly bright and the range of colors is way better than most krypton argon mix gas ion laser I've seen.

Hey Kev,

nice projector. Whats a "shim" ? I like that you don't need a second mirror for green and red, to adjust height.....

The lasever site says their new modules are 'adjustable focus'... is that true ?

That would be really handy for RGB as you can compensate for different beam sizes and get it mixed properly....

Anyway.. keep up the good work!

Cheers,

Adrian

Some pictures of the show I did with my RGB projecotr over the weekend

http://web.mac.com/goodbeer/iWeb/goo...xperience.html

http://www.flickr.com/photos/mayhem/...7594155422671/

These of couse do not do justice to the show which was absolutely amazing.

That looks really good, its amaizing how analog modulation gives nearly the same effect of having a pcaom.

Amazing configuration for sure :)

I see that you use the small Lasever green laser on the second picture (I consider to buy a blue or green of the same model), so what do you think of it? These looks great but the only point that I'm not sure is that they recommand to run it at 20-30°C. So what's if under 20°C ?

Nice stuff.

Regarding the new style lasever psu in the second pic.

I would recomend mounting a heatsink to the side of the power supply that the power semiconductors are mounted to. The power supply has been designed with this in mind.

I looooove this :)

NICE !!!
But it kills me to know that your system have more power than me :twisted:
I did have a 240mW green , but I will only need 100mW.. so I did order a smaller green dpss :roll:

More and more I se your pictures I sure hate to se my system standing on the table going nowhere :( with no green laser and no blue laser that is working....

I`m pretty close to order a new and bigger blue..
Becouse I HATE waiting...



But great system you got there :) :) :)

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Originally Posted by dave

Nice stuff.

Regarding the new style lasever psu in the second pic.

I would recomend mounting a heatsink to the side of the power supply that the power semiconductors are mounted to. The power supply has been designed with this in mind.

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i have the same PSU and i not notice lot of heat from the side.
but i recommend to fix the bottom of the blue laser head on a large metal piece because i think there is a peltier cooler/heater inside like the mine (green) and they need to dissipate large amount of power i think.

Junktronix,

Looks fantastic. What would you estimtate your total $$ investment in the projector?

Thanks.

G