New Member - Intro & Questions

[setsinmotion]

Hi,

Firstly can I start by saying what a fantastic forum this is. I've been lurking for a while and absorbing as much as I can. I can see that this hobby is going to cost me a lot of time and money! There seem to be very many knowledgeable and helpful folks on here, I hope you don't mind if I ask a couple of noob questions.

My eventual aim is to build a multi-colour laser projector for basic animation. At the moment I have purchased a (reported) 50mW 532nm Laser Module which seems to work well (at least a green beam comes out of the black box!). I have also purchased (Norms) DAC and can draw pictures on my scope (woo!). I was going to build a Sound Card DAC but figgured it would be faster just to buy one from fellow forum member.

Now to the questions:

1. Galvos - I need to buy, but I'm torn t what to buy. I was looking at a low cost 20Kpps set from LaserWave. Hving spoken with Rob, he suggested that I might be best off going with the 30Kpps set - probably good advice. I can't make my mind up as at this stage I'm only experimenting and this is unlikely to form the final projector. The cost is almost double (but obviously a better product). Thoughts? (If anyone is upgrading and has any for sale- please let me know!)

2. Safety -I've read a lot about safety when using the projector out in the field and safety features build in to the device itself - what about when building and playing? Obviously I shouldn't look in to the laser with my good eye - do you wear protective glasses when building?

3. Given my 50mW 532nm laser above, if I wanted to add Red to it, what size of laser would you recommend?

4. On some of the builds I see a mound in front of the laser before the 45 degree dichro reflector - what is this, some sort of filter?

5. Alignment - is there some guid about how to align two or more lasers in a projector?

Sorry for all the daft questions, hope you guys can assist.

Cheers,
Keith
(Scotland)

[Jem]

Hi Keith & welcome to Photonlexicon

Firstly, if you've already spoken to Rob, that is a huge step in the right direction. You'd have to go a long way to find someone as helpful and knowledgeable. Rob is a well trusted and respected member of this forum.

As for aligning lasers, I believe Rob wrote a guide as to the easy way to do this. If you can't find it with a search perhaps you could PM him and ask if he can send you a copy. With regard to the galvo's, I guess it depends on whether you want to spend the money now or later

I guess if you have the money available you may as well spend it now and get something that will see you well into the future. Be warned though... This hobby is a complete money pit and your wallet will never be quite the same again

Having said that, it's also a hobby that will bring you great enjoyment and satisfaction, and you'll also have the opportunity to meet som wonderful people - welcome aboard !

Cheers

Jem

[Lasermad]

Wow Brilliant another scottish member , welcome keith , Jem summarised it all pretty much ...its great to have another scotsman around so welome and hve fun !

PAUL

[Dr Laser]

Hi,

3. Given my 50mW 532nm laser above, if I wanted to add Red to it, what size of laser would you recommend?

Cheers,
Keith
(Scotland)

100mw of 635nm
~150mw of 642nm
~200mw of 650nm
~300mw of 660nm
~400mw of 671nm

To have RGB you need 70mw of 473nm blue.

[hobbybob]

Hi Keith,

Welcome to PL.

Will try to answer some/most of your questions to the best of my ability.

Hi,
Firstly can I start by saying what a fantastic forum this is. I've been lurking for a while and absorbing as much as I can. I can see that this hobby is going to cost me a lot of time and money! There seem to be very many knowledgeable and helpful folks on here, I hope you don't mind if I ask a couple of noob questions.

I don't think there are n00b questions. There's tons of knowledge in here, everyone in their own field of business (electronics, mechanics, gas lasers, diode lasers, software).
So if there is a right place to come to, it's here.

My eventual aim is to build a multi-colour laser projector for basic animation. At the moment I have purchased a (reported) 50mW 532nm Laser Module which seems to work well (at least a green beam comes out of the black box!). I have also purchased (Norms) DAC and can draw pictures on my scope (woo!). I was going to build a Sound Card DAC but figgured it would be faster just to buy one from fellow forum member.

If you have Norms Dac there's no need to build a Sound Card DAC ?
If you can already draw pictures on your scope, it's just some galvo's you need and you are on your way.

1. Galvos - I need to buy, but I'm torn t what to buy. I was looking at a low cost 20Kpps set from LaserWave. Hving spoken with Rob, he suggested that I might be best off going with the 30Kpps set - probably good advice. I can't make my mind up as at this stage I'm only experimenting and this is unlikely to form the final projector. The cost is almost double (but obviously a better product). Thoughts? (If anyone is upgrading and has any for sale- please let me know!)

I would go with some DT's from Rob. He's a nice bloke, the scanners are good and he can always give you sound advice. And he is in the UK which will save in Shippingcosts.

2. Safety -I've read a lot about safety when using the projector out in the field and safety features build in to the device itself - what about when building and playing? Obviously I shouldn't look in to the laser with my good eye - do you wear protective glasses when building?

Depends, if i am just watching it project onto a wall, no. If i am aligning stuff, YES.
Rob also sells these, think of it as an insurance. You probably never need them, but if you DO burn out a retina you cannot see those lovely photons for ever. And the picture of your loved ones. So be safe and buy a pair of safety goggles.

3. Given my 50mW 532nm laser above, if I wanted to add Red to it, what size of laser would you recommend?

See the answer of Dr. Laser above. Or try the search function and search for Chroma, a program made by a PL member named Tocket. This program will let you input wavelength and power and show you how your color (white) balance is. Although there is always a difference between practice and theory it gives a good idea. Especially comparing for instance "What if i add 200mW of 655/660nm red (DVD burner diodes) or i invest in a 642 red. Very handy tool and an absolute must in your digital laser toolkit. And most of all. FREE !

4. On some of the builds I see a mound in front of the laser before the 45 degree dichro reflector - what is this, some sort of filter?

Can you refer to a picture ?
Sometimes it's a mirror mount, when people want to combine 2 beams of the same color.
Most people start with green and that only needs to be deflected and guided through the dichro's.
But if you refer to a specific picture i am sure someone knows.

5. Alignment - is there some guid about how to align two or more lasers in a projector?

Rob (Stanwax on PL) has made a guide, i looked it up a week or 2 ago for someone.
EDIT: here it is: http://www.photonlexicon.com/forums/...-for-alignment

Sorry for all the daft questions, hope you guys can assist.

Well i hope this helped a little bit ?

[buffo]

I hope you don't mind if I ask a couple of noob questions.

Welcome to PhotonLexicon, Keith. Sorry I missed your introductory post earlier. Looks like Jem and hobbybob have answered your questions quite well though. The only think I'd like to add is a suggestion to check out the Scottish Laser Enthusiast's Meeting (SCOTLEM) that they're planning over in this thread. If it's close enough for you to make the trip, I strongly recommend that you attend.

You'll get a chance to see what it is you're getting in to, and you'll also meet some really great people. They'll answer your questions and offer plenty of advice. They'll also show you what they've been able to put together themselves (and some of the kit you'll see is nothing short of amazing). This sort of thing is sure to inspire you to build your own...

Finally, these events are quite social in their own right, and besides, who can resist a day of watching cool laser shows?

Adam

[setsinmotion]

Guys - thanks for the warm welcome, and thank you for the answers to my questions.

Since I first posted I've bought a set of 50Kpps LW Scanners from McCarrot (cheers!). I also inherited from a friend a somewhat broken 150mW (I doubt this very much) scanner which had broken mirrors.

I successfully retrofitted new mirros to the X/Y galvos (thanks T0mmm) and plan to hook it up to my DAC instead of the ATMEL controller to see if I can get PC control of the laser.

Anyway back to the questions - I'm off to buy a set of safety glasses and a Red Laser module from Rob (stanwax), heard nothing but great reports about him - obviously held in high regard. I've just read the alignment document - brilliant, clears that up nicely. I'm going to try out Chroma to spec out my Red laser.

I've gone back through the forum posts to see about this mystery mount that appeared in front of the laser but I can seem to find it. I'll keep looking.

One more question that has come to mind - UV filters. Do I need one? And if so, why?

I plan to go to the SCOTLEM, it's only a couple of hours away from me - sounds like it would be awesome!

Thanks again - this site rocks and my wallet is getting smaller for it!

Cheers,
Keith

[gottaluvlasers]

Hi Keith-

Welcome my friend! Your wallet is going to hate you for the rest of your life now!

I've gone back through the forum posts to see about this mystery mount that appeared in front of the laser but I can seem to find it.

Yes. this one I cant seem to figure out either. Im thinking maybe a shutter?? Or perhaps you were loooking at a dual laser setup that was using a PBS cube and mount?

Like this-

I'm off to buy a set of safety glasses and a Red Laser module from Rob (stanwax), heard nothing but great reports about him - obviously held in high regard

Top Notch fella!!! He gave me *cold* beer when i went to England!! You won't go wrong with doing business with him.

I've just read the alignment document - brilliant, clears that up nicely

It does help immensely. However, still be very patient for your first time. It can be a pretty tedious process.

UV filters. Do I need one? And if so, why?

No. No Lasers you are using emit a UV danger. 405nm "blu ray" would be the closest. But even them you dont need a UV filter.

-Marc

[buffo]

Some people purchase UV filters that are designed for camera lenses because they have very good anti-reflection coatings for visible light. (That is, they don't reflect much - if any - visible light.) So they are well-suited as an aperture window for a projector enclosure. The fact that they filter UV is irrelevant; the advantage is that they are an inexpensive source of quality A/R-coated glass windows.

Still, there's nothing that says you must have a glass window over your projector aperture. You can just leave it open and it will work fine. You might get a little more dust on your optics, but that's not a big deal. (Cleaning isn't difficult.)

Adam.