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[30 Colors] Beam Combiner + Beamshot

691175002

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Update2: The second part of the project can be found in post 16: http://www.laserpointerforums.com/forums/YaBB.pl?num=1233639271/16#16
Contains TTL and microcontroller + 16 color beamshot.


My next project is to build a yellow laser by combining red and green like rog demonstrated, however in a more controllable and adjustable way (I'm not confident in my glue and wire optics-aligning skills).  This build is turning out to be more complicated than I anticipated because of all the holes that need to line up.  The drilling and tapping takes a fair chunk of time as well.

Work so far:


Bottom:

The o-rings and screws allow fine adjustment of the up-down angle of each laser (as well as the height of each to a small extent).

And here is the plan for the optics:

I will be doing a similar setup for the optics, the splitter will rotate forward and backwards and the mirror will rotate side to side to allow aiming across all axes of both translation and angle.

I did some playing around with the optics and discovered that the PHR beamsplitter transmits red very efficiently no matter what the polarization, and reflects green and violet very efficiently as well.  Between the front surface mirror and the beamsplitter, this setup should allow near 100% efficiency for making yellow or magenta.  Since both modules are held in decent aluminium heatsinks, I can foresee some substantial power coming out of this unit.

I chose plexiglass for the base mainly because it was all that I had laying around, an advantage to a non-conductive material is that I wont have to worry about the case polarities of the various lasers.  I plan to paint the touching surfaces of the heatsinks with some clear nailpolish to electrically isolate them.

I'll see if I can finish it up tomorrow. Unfortunately all I have for lasers is some 5mW reds and greens so there wont be much I can do with it until my 22x diodes show up (shipping is taking a looooong time).


--------


Update starts here:
Ok well I ended up procrastinating a fair deal and then I managed to break my 4-40 tap working on another project (First tap I've ever broken, I heard that you could shatter the tap by repeated heating and cooling and then I turned the part I was working on into an aluminium puddle...), and forgot that two of the holes in the acrylic needed to be threaded (was too long since I worked on it...) so I ended up remaking the mount for the beam splitter.


Almost done...


Powered up and aligned.  Alignment was pretty easy however when I do it again I will be drilling all of the unthreaded holes slightly undersize.  As it is, turning the screws can shift the parts around very slightly.  Also, you need to hold it by the acrylic base or the heat sinks will shift slightly under the pressure which is somewhat inconvenient.


Beamshot, using a pair of dying AA's.  Right now I am using a 5mW aixiz module and a 5mW o-like module.  The green completely overpowers the red normally but after the batteries start to wear down you get some nice yellow/golden colors.


Beamshot #2.  Since the beams are both so weak I had to use a crapload of smoke, which may be responsible for the beam changing colors over its length.  Either way, it looks super cool.

I learned a a lot of things making this and I will probbably track down a 0-80 tap for the next build.  I am hoping to compress this down into the width of a CR123 battery.  I have a few drawings where everything fits so I just need to collect some material and get working.

This thread is far from done though, once it gets darker I'll replace the batteries, hook it up to a microcontroller and put together a many-color beamshot for you all.

Update2: The second part of the project can be found in post 16: http://www.laserpointerforums.com/forums/YaBB.pl?num=1233639271/16#16
 

hydrogenman15

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Re: In progress: Yellow Beam Combiner

Nice setup! I also am using plexiglass for my RGV.

--hydro15
 

rog8811

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Re: In progress: Yellow Beam Combiner

I await results with great interest :). One thing you will come across is the disparity in beam diameter, which is more noticable up close, at a distance the eye seems to filter out that difference and you will perceive a good yellow. Nice project.

Regards rog8811
 

Cyparagon

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Re: In progress: Yellow Beam Combiner

So... how large is that cube? Are you sure a red beam will fit in it?
 

diachi

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Re: In progress: Yellow Beam Combiner

Where is the green module :-? Are you making this so the laser modules can be swapped ( violet + green ) so that you can change the colours about ?

or am I missing something ? ::)

It looks nice so far anyway :cool:
 

691175002

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Re: In progress: Yellow Beam Combiner

For the pictures I just test assembled it with some 5mW reds (one of the modules doesn't even have wires coming out of it). The final version will be intended for a red + green but the modules can be easily swapped out via the set screws.

The cube is about 6mm x 3mm but I have played with it in the past and while it is small, it can fit a red beam when rotated so its long axis is horizontal.

If this works out I will probbably try to compact it into as small of a space as possible (and perhaps throw in a third module for RGV) and then bolt in into some tubing for a pointer.
 

laserwanabe

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Re: In progress: Yellow Beam Combiner

It probably wont be an easy swap every time, if you plan on swapping your probably going to have to tune optics anytime you swap.
 

691175002

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Re: In progress: Yellow Beam Combiner

laserwanabe said:
It probably wont be an easy swap every time, if you plan on swapping your probably going to have to tune optics anytime you swap.
I will definitely have to realign the optics, but its always nice to have the option to switch out the lasers at a whim. I was playing around with some 5mW modules to get a feel for how well the o-rings and screws work and its better than I expected, I can get very accurate and consistent alignment without much trouble, and the screws don't wander.

That being said, I bought only 4 o-rings from home depot (massively overpriced) and I am not sure where I should look for more very small o-rings. My backup plan was to use a square of felt since I can't find any rubber sheeting.
 

andy_con

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Re: In progress: Yellow Beam Combiner

the thin plastic base, where did you get that from??

i need some
 

691175002

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Re: In progress: Yellow Beam Combiner

The plastic is just some lexan scrap.  There is a plastics place somewhat nearby that has a scrap bin.  They have assorted thicknesses/colors/types etc so it can be fun to look around, and small or slightly scratched pieces sell for pocket change.  Many places have scrap/offcuts if you ask nicely and will either give it away or sell it very cheaply (Metal places sometimes make a business out of selling scrap though so its different there).

Last time I checked, home depot also sells small pieces of Plexiglas for picture frames/windows. I only used Lexan because I had a small piece already laying around. Hard plastics can be a pain to drill and tap.
 

Flingster

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Re: [UPDATE: Finished] Yellow Beam Combiner + Beam

WoW! Great work looks beautifull :D
 

Benm

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Re: [UPDATE: Finished] Yellow Beam Combiner + Beam

It does look cool, sort of a rainbow effect in the beam going from green to red. Green scatters more than red does, so it makes sense that it does that to some degree.

Could you post some pictures of the spot on a surface at several distances?
 
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Re: [UPDATE: Finished] Yellow Beam Combiner + Beam

Cool, man! Great work there :D



I'd love to see a 40-50mW green module with a 200mW red in that setup ;)
 




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