What if.....

[hobbybob]

i have 2 lasers with a beamheight of 29mm (R and G) and one (Blue) with 31mm beamheight ?
I have bought Edisons first build, put in a blue and are able to align it using the mm mounts.

Is this possible or do i just THINK i can align it and will blue "walk" away from Red and Green after a long distance ?

It's my first RGB and i was just wondering.

[gottaluvlasers]

Hobby-

you are going to have to elevate the R and G lasers to align near field with your B laser. once that alignment is set, your far field can be adjusted.

-Marc

[tocket]

Another way to do it is to have the blue laser pointing slightly downwards. Not as elegant perhaps, but near field alignment is all about having the beams hit the same spot on the dichros.

Something to keep in mind of course is heat transfer - if your blue laser needs additional cooling from the base plate this is not the way to go.

[hobbybob]

Thanks guys, will take a look and measure, since the RGB datasheet for the new models says it's leaving at 31mm height, but this one (a refurbished previous model) might be lower.
Unfortunately i broke the LCD of my new camera, have ordered a new one yesterday (costing 65% of the newprice of the camera!) when it's repaired i post pictures of my progress.

[Banthai]

Duh ..... just learn from the master ....

Bob i have different heights on my lasers but with my layout .... no problem

checkout my old thread ( god it really is that old now ? )

oops ... sorry my browser wont let me do a search ... as im working out in the Lebanon ... with a really poor slow internet connection ( about 200 baud )

look for banthai beast and all will be revealed

good luck Bob

and all the best ... Karl

[mccarrot]

The best option is tot CNC 2mm off you baseplate at he location of your blue.

[CDBEAM]

HB,

As I am currently doing a major modification to my RGB. by adding a LaserWave Red 640nm....I have run into the same problem......different beam heights for different laser heads !!!! My Lasevers ( Green and Blue ) have a beam height of 25.4mm. My Maxyz Red 658nm has a beam height of 12.225mm. My LaserWave Red 640nm has a beam height of 29.0mm.

For now...I am experimenting with a series of VERY stiff 8mm diameter springs. They are very stiff and give NO unsolicited vertical movement. Springs are located between the Laser Head base and your optical level platform at each corner of each Laser Head. Each spring is secured with an 8-32 NC bolt...thru the LH body, thru the spring and into a threaded bore in the platform. Such an arrangment DOES deliver great adjustabillity to acheive precise positioning for the near field alignment needs. That is good part !!

The possible negative aspect MAY be this:

The 8-32 bolts could unscrew and cause a misalignment... I may need to use some type of thread seize compound to prevent bolt movement??

Currently I have additional Fan chilled / Peltier cooler plates attached to the underside of my optical level platform positioned directly below the Green and Blue Lasever Laser Heads. I am not convinced that this is really needed considering the massive heatsink provided by the Optical level platform.....but I decided at the start of construction to build with this level of Thermal managment....Bottomline is now...with the springs addition....an air gap results....and air IS an excellent insulator.....so the effectiveness of my Peltier cooling is greatly reduced.....as is the effectiveness of the passive cooling provided by the mass of the Optical level platform....I have no solution for this POSSIBLE problem....yet !!!!

In conclusion....In a Perfect World....ALL Laser Head beam heights would be at SOME standard elevation....hey....29mm sounds good !!! AND...ALL beam propagation would be completely parallel with the Laser Head bottom and side....this is NOT the case as some manufacture's beams are NOT emitted at
a true 90 deg to the OD profile of the Laser Head !!!....In a Perfect World we would not have to deal with this CRAP !!

Any ideas on my thermal managment issues...PLEASE speak up !!! See attached pic....

Thanx...CBBEAM !!

[Things]

Yeah, I was surprised to see the huge base on the laser-wave red too. I havent personally owned many other types of lab lasers, however the red runs perfectly un heatsinked, but since it's the highest laser it is on the baseplate anyway.

The spring idea sounds cool, though.

You could try it, and if heat is an isue, you could get some alu block mounts made up, or mount some heatsinks on the lasers?

The changing beam height sure is a pain. What is an even bigger pain is beam angles!!

Problem is there is no standards for laser modules. If they emit light, no one really cares :P

[hobbybob]

Thanks for all your considerations. I used a similar spring system in the first projector i built under my scanners. That was before i knew photonlexicon.
Check it out: http://www.xs4all.nl/~hobbybob/laser...able_galvo.jpg

The strange thing is i was able to align it very easy.

What could be happening here since this is an older model blue from RGB lasersystems that has been refurbished, that newer models have the 31mm beamheight and that this one is lower.
Will measure it over the next few days when i have time and then make up my mind.
If i have to raise the other two by 2 millimeter i just cut up 2 metal plates and places those under the other lasers. Although the other heads are a Laserwave and a Kvant and not the more hot running Lasevers, i don't want to lift them with springs because then there is no need for a 10mm baseplate as well IMO. I want good cooling and that's how i designed it ;-)

Also shimming them up will pose this same problem: cooling will be much less.
The blue RGB module is a very heavy block (almost feeling solid!).
So want to cool this as well.

I hope to expect to receive a new LCD screen for my camera, which i accidentally broke, so then i will be able to post pictures.

But just to make sure: if i have all the spots hitting the dichros on the same level is that what people call near field alignment, or is nearfield directly after the scanners ?
What i noticed also is that i need to get the beam onto the mirrors correctly.
I think from my other builts it's best to hit both mirrors spot on in the middle, right ?
Since then the mirrors have the best way to move the beams around ?

Furthermore i noticed when i turned the green down quite a bit i see some crinkling in the whitish laser output. I mean all beams on full gives a greenish white, i turn it down and then i see some fluctuation in the beams by kind of crinkles and flickering and stuff, is that what people call jelly beaning ?

[carlos3621]

Use aluminum shims for th R and G lasers, with heat transfer paste , between the shims,
this way , all your lasers are using the baseplate as a heatsink