Building My First Projector

[brainal]

About two weeks ago I started doing research for this club that I work at about lasers. After offering the suggestions on what to buy they took the worst course of action and got some brutally bad American DJ trash, o-well that's what they get for trying to be cheap. Anyways during the research process I got totally hooked on this hobby/addiction and have decided to build my own RBG laser. After doing so many hours of reading on this forum mainly plus some other places I just wanted to lay out what I learned/ plan to do and if any of you have the time to point out if I'm missing anything glaring. Mainly from this building I want to get my hands wet dealing with lasers before I start doing anything too crazy and burn an eye out.

1) Safety first during construction and use. This was one of the first things I read about the FDA regulations and such plus the dangers that occur during the alignment issues. The best bet here is to buy goggles that project against the certain type of wave length that may brush across the eye.

2) Scanners - Give movement to the light beam once it is combined by the Dichros, different speeds give different resolutions which is better for projection better animations. Are connected to a "show card" such as PT-Itrust

3) Optics - Use the 3D holder for the dichros/bounce mirror. The Dichros usually allow green to pass and reflect red, than pass red/green and reflect blue. A bounce mirror is usually used to make the alignment process easier. For alignment the goal is get the beams to hit the glass is the same location. This is usually tested with a circle to make sure the colors are over lapping.

4)Lasers - Mainly here the most important things are wavelength, power, and modulation. TTL is worse than analog as analog allows for power vary instead of just on off.

5) DAC/Software- Woah this part I've prolly spend the most time the last couple of days look at and I came the conclusion that I'm going to need to save up and buy QuickShow with its DAC. Untill I got those $600 bills to throw down I was sadly I know its DAC blows but the iShow for $48.00 which seems like a steal for something to get some beam shows started. But the DAC on the iShow i believe has like 8 bit compared to 16 bit of the QS but hey you cant have it all on the first try.

So after that alittle review of what I learned this is what I was planning purchasing:
-PT-20K w/ PI-Trust = 119.99
http://shop.spacelas.com/pt20k-high-...ard-p-203.html
-100mW 532 Green Laser = $79.99
-200 mW blue 447nm laser diode = $92.00
-200mW red laser diode 655nm = $49.00
From spacelas + like $80.00 shipping which seems extensive so I'm going to see if I can get similar stuff from USA or something

-3D-Holder x2 = $50.00
-Reflect Blue 445nm = $2.00
-Reflect Red = $2.00
-Box A = $55.00
-iShow = $48.00
From Golden Star Laser

It comes to like $187+$340.95+$84.00 = $611.00
At that price I could be two REKE lasers for the same price but i think with a slower scanner plus no DAC. I love to hear your thoughts and your suggestions, and thank you very much for your time and amazing information available on this forum.

[Bradfo69]

Humm... where to start.

I'm going to take an initial stab at this and go on the assumption you are in the US. If that's the case, and you've done as much reading on here as you've indicated, then the first thing to ultimately think about is what you're building this for. Is it for commercial use? Or, is if for personal use at home? If you ever intend in any way to use this for public display, then you've got a long road to hoe and your assortment of parts won't get you there. As a hobbyist and as a means to learn more about lasers, it's a start and this isn't exactly the cheapest endeavour you're going to embark on. Many others are in your shoes. But what you're building won't be anything you can do public shows with.

My first thought is initially with your scanners. PT-20's, as you will find out if you get them, will only be satisfactory for a short period of time. I'm not necessarily knocking them. They have their place and, even I just recently purchased a set but, that is primarily because I'm selling a laser to a noobie friend that already had PT-20's and they went bad. He knows what he's getting and what it will and won't do. You really want to try and save a little and buy a better grade of scanners. Kind of like the analogy with a stereo in that you want to put 50% of your budget into your speakers because they produce what your HEAR. The scanners are going to produce what you SEE. Even if you only go up to DT-30's, I think you will find it's a vast improvement in your viewing experience and not something you regret a month later.

You're laser selection? Not bad. Not great but, on a budget, not bad. That's an area where you can improve some piece by piece. Just keep in mind you get what you pay for. And the old modules
can be incorporated into other projects down the line like lumia if you ever decide to check into that.

There are a number of other things not on your list such as power supplies, wire, perhaps an AR window if the case doesn't come with it, and other internal boards etc. Budget another $200 for all thouse little things you don't even know you need. Drill bits, taps, screws, solder, heat shrink tubing etc. You'll be nickle and dimed to death with all the other things you'll stumble across.

I'm sure others will chime in but, building your own is admirable and for sure, a great learning experience but, nothing about this hobby is cheap and realistically you should be thinking more like $1000 rather than $611. You're better off hard as it is, to save and spend more on quality components and have it take longer to build than to go the cheapest route as it just doesn't pay to buy the least expensive parts. I've paid more for shipping a good projector than the total of what you've proposed.

Just my .02 as I hate to see you throw good money towards something that's going to be less than satisfactory.

[james]

The first thing you should look for is a nice piece of thick Aluminum plate!

You need a good optics table. Unless you are into the idea of making it all very tiny, you should think about spreading the individual parts out on the table and leaving room to change parts and upgrade in the future.

Get yourself a nice set of numbered drill bits, some taps and some cutting oil!

James.

[LaNeK779]

first of all, wellcome and well done on deciding to make your own!!

you have most of the theory well established in your head allready, sothat makes suggestions easier


1) given that you work with lower powers, a pair of safety goggles will block off all light at the given wavelength, so you will not see what you are doing. An alternative course of action is carefull planning, turning the laser power way down (an adjustable 0-5v power supply helps in this, to immitate a modulation signal) and either putting on a pair of sunglasses or two, or taking photos of the parts you are working on, to see what is actually happening. I find that using the flash also helps, as it reduces camera saturation. Safety goggles are a must at most cases, but during aligning they are not so usefull to me.

2) I would also ask around for a set of used DT25 ot DT30, instead of the PT20. I have PT40 and they are ok, I also have DT25 and they are too usefull (so usefull that maybe none will be willing to sell them). A good idea would also be to use a breakout board to wire everything ( http://shop.stanwaxlaser.co.uk/gener...oard-365-p.asp ) and have the iTrust card in its own seperate box.

3) Here are more possible dichro setups http://www.stanwax.plus.com/lw/dichro%20layouts.pdf In general, you want your strongest colour, possible the blue these days, passing through as many optics as possible, because there you have light to "waste". So a good order could be blue - green - red. And here is a helpfull guide in aligning http://www.stanwax.plus.com/lw/rgb%20alignment%20lw.pdf

4) Here it all dependes on how complicated you want to make it. At the moment, i would go for single mode diodes for red and blue. If you can't afford the expensive and sensitive opnext HL63133DG, you can try combining two of the single mode 110mw mitsuishi ones. The 638 nm wavelength is extra bright and you will not regret it a bit. i would actually advise against the 655 - 660 wavelengths. Sample and pricing here https://sites.google.com/site/dtrlpf...le-mode-diodes . the same gows for blue.. there is the normal 445nm "monster" spewing out more than a watt, and there is a 100mw single mode one, so again you have to use two ( https://sites.google.com/site/dtrlpf...m-pl450-diodes ). Ok, this is a more complicated route. You will need more optics, diode mounts, alignment but you will learn an awfull lot and you will make something that is more DIY. The great advantage using these diodes is very good quality beams that can fit on small galvo mirrors (so higher scan speed and less flicker)

5) Well, other alternatives are also available, cheaper too. But i will not even try to go against the pango tide here. it is pointless...


What i want to say as a closing remark, is that you don't have to make it all at once. You just need to calculate how much space you will require for all three colours and extra boards etc and sort out the baseplate and box. Then, you can go about adding one colour at a time

[brainal]

But yeah building it is just for my hobby, I got into building one though researching for the place I work at. But yeah for the place I work at there looking to buy like a 3000-5000 dollar laser but there are still on the fence about the whole thing cause of safety and like how long will it last and such. The research into building one will certainly make sure that we are getting something of high quality/ FDA complaint.

For my personal built you are all totally right with buy quality over time. Thank you so much for your advise on the lasers to buy and such, I will update on my progress in the next few weeks as work as been going crazy, over 7k people on sat and sun.... insane but thank you for all your time in your responses

[White-Light]

Just a quick note, FDA compliance isn't quick or particularly easy to get on a self build from what I've read from our US friends.

It might be worth considering a quality turnkey approved solution if you're not prepared for a long haul and you're looking for a commercial solution for your work place.