Help driving many laser diodes.

[Helmholtz Watson]

I can see what you're saying, but unless the lasers enter from evenly spaced holes in the sphere and converge at a central point it won't be a mock-up of the NIF, it'll just be an expensive ornament.
I really do like those 3 screw mount/heatsinks though. They would look brilliant but would be prohibitively expensive for 48 of them.
I def. want to include the idea though. Maybe 1" lengths of copper pipe cut into tabs at one end with sprung adjusting screws like Jayrob's. Poor pic alert:

1" copper pipe top and side view. Cut along red lines down about 1cm and fold 4 tabs out and use pliers to make flat.
Drill holes through tabs for machine screws.
Add screws and springs.

 

[bobhaha]

AHH... yes I see.. BTW I didn't mean those exact ones... those are made for heat dissipation... I'm sure you will not need such a bit bulky thing like that.. it was more for the example of the adjustment screws. Also I like your idea about the copper tubing that is a great idea I'm not sure what you mean by...

Cut along red lines down about 1cm and fold 4 tabs out and use pliers to make flat.
Drill holes through tabs for machine screws.
Add screws and springs.

But it gave me another idea... once again sorry for crappy pics!

So basically, I went with your idea with the flat edges, and thought of a way to incorporate the focusing in with it... not exactly sure how its gonna work out, but just another idea to think about..

EDIT: ohh... I get ya... didn't understand the first time I read it.. yeah that would work.. but I'm not sure if is is as precise as my design, but then again I don't even know if my design will work LOL

 

[Helmholtz Watson]

I was trying to describe what you've drawn except the screws would be much shorter and sprung to cut down on wobble and the pipe would be outside the ball.

 

[bobhaha]

Ohhh I see... yeah cool idea! test it out first tho.. not exactly sure if it would work how you wanted.. but yeah good idea!

 

[RA_pierce]

Maybe I'm crazy... but why not use a couple different laser types?
Were I to build this... I would use 2 500mW 808nm diodes for the real burning action.
This is cheaper than many violet or red diodes.
Since I like green, I would put a few inexpensive (O-like comes to mind) 5mW green modules in there...
Also... since the beams are pretty much useless inside the contraption... I would make a beam exit at the top with a diffraction grating to simulate many lasers from one device.
It would be cheaper and easier I think, and just as effective.
Since the lighting action is concealed and the only escaping light is from a few 5mW greens, there is no need for using safety goggles either!

 

[bobhaha]

This means the following aspects of the design are not up for debate:
1) Must use many lasers, at least 10 preferably more like 30
2) Must have lasers mounted around the surface of a sphere pointing to a central focus point
3) Must have a tube leading to central focus point for "sample" (ciggie) insertion

Read the thread!... BTW I would of done the same!

 

[HIMNL9]

Use a number of lasers NOT in pairs, and don't place the modules in the way that they hit other modules ..... as example, placing them in the way that, when a module is turned on, its beam always hit the space between other modules, inside the sphere, can be a system for avoid to burn them reciprocally .....

Also, maybe it can be more "aesthetic" placing the guidance tube from the top, maybe with a microswitch or a photocell on the top, so the assembly become automatically turned on inserting the cigarete .....

But, imho, the better thing can be quit to smoke .....



Edit: also considerate that the most part of the zone hit by the beams is white (paper of the cigarette) ..... maybe better thing can be the use of some PHR diodes ? ..... red don't have so much efficency, with white targets.

And another thing ..... if you realize your model using as base a sphere made with fluorescent plastic, the final effect, when all those BR turned on inside, can be ..... well, "very bright", i suppose

 

[Helmholtz Watson]

Maybe I'm crazy... but why not use a couple different laser types?
Were I to build this... I would use 2 500mW 808nm diodes for the real burning action.
This is cheaper than many violet or red diodes.
Since I like green, I would put a few inexpensive (O-like comes to mind) 5mW green modules in there...
Also... since the beams are pretty much useless inside the contraption... I would make a beam exit at the top with a diffraction grating to simulate many lasers from one device.
It would be cheaper and easier I think, and just as effective.
Since the lighting action is concealed and the only escaping light is from a few 5mW greens, there is no need for using safety goggles either!

If the beams exit the ball, the whole project was completely useless...
The lasers have to be all the same low power for safety and because they are all equivalent and the same wavelength in the NIF.

Use a number of lasers NOT in pairs, and don't place the modules in the way that they hit other modules ..... as example, placing them in the way that, when a module is turned on, its beam always hit the space between other modules, inside the sphere, can be a system for avoid to burn them reciprocally .....

Also, maybe it can be more "aesthetic" placing the guidance tube from the top, maybe with a microswitch or a photocell on the top, so the assembly become automatically turned on inserting the cigarete .....

But, imho, the better thing can be quit to smoke .....



Edit: also considerate that the most part of the zone hit by the beams is white (paper of the cigarette) ..... maybe better thing can be the use of some PHR diodes ? ..... red don't have so much efficency, with white targets.

And another thing ..... if you realize your model using as base a sphere made with fluorescent plastic, the final effect, when all those BR turned on inside, can be ..... well, "very bright", i suppose

The ball will be a clear acrylic sphere, so shouldn't fluoresce under red/IR.
The point of this project is to make a "working model" of the NIF, so any deviations from the NIF design spec will only be made for practical reasons (i.e. 500TW is a bit too much power) not aesthetic reasons (having lasers doing anything other than what has already been described or moving the angle of the sample tube).
Having the sample tube top mounted would make it easy to drop the cig into the ball too.
Any design feature of the NIF I can replicate has to be, as there's plenty that I absolutely can't.

And I'm not about to start with that healthy living nonsense. All you ppl telling me not to smoke are going to look mighty stupid when they're in a hospital dying from nothing.

 

[HIMNL9]

I'm not about to start with that healthy living nonsense. All you ppl telling me not to smoke are going to look mighty stupid when they're in a hospital dying from nothing.

But you know, we non-smokers MUST break the ba**s of all the smokers, always saying them to quit smoke ..... no matters if we're in a hospital dying for chocolate addiction, ice cream indigestion, or some other funny disease ..... it's our mission .....

(J/K )



EDIT: seriously, what do you think about the use of the PHR and fluorescent plastic ball ? ..... other than this, cause you don't use your assembly for long time, like a pointer, you also don't need to use full modules, and if you have some modelist skill, can also "mask" the connection wires as "pipes" or other external elements, making it more similar to the real unit

 

[Helmholtz Watson]

I don't want a fluorescent ball because I'd like it to barely appear on until the puff of smoke suddenly reveals the 48 beams. I would like to try and make the outside of the ball look as "industrial" as possible, by hiding all the drivers in the base of the model and connecting all the diodes with stiff gray wires to look like pipes.
I think the coolest way would be having one very powerful laser focused onto a bunch of 48 fibre optic lines inside an enclosure, with the fibres then going into the ball. That said I don't think it's practically possible to focus light coming out of a fibre cheaply.

 

[HIMNL9]

Uhm, a 40W fiber coupled FAP unit can work, but then you need a hell of power supply

and what about use, like, 18 (or 24) aixiz heads, fixed inside the sphere, in 3 rings with different planes, all focused on the end part of the guidance tube ..... i mean, all inside, so you can reproduce on the external the exact appearance of the real unit, if you want ..... all that what you need to do, is keep them inclinated enough so the beam coming from a head go and hit the space between two heads at the other side of the ball ..... so, no risk to burn a laser putting another inside it .....

the draws are not too much good, cause corel don't have a 3D module, but i hope it's clear the same

 

[Helmholtz Watson]

Yeah that's what my first drawing would be like extended into 3D. MS Paint is even worse than corel
I'd have it so each laser was paired with a "backstop" of some sort, probably just a sticker on the inside of the ball to avoid overshoot.

 

[HIMNL9]

Uhm, i hate stickers, they tend to detach, with the time ..... if i can suggest you an alternative, there's a black matte paint selled in spray cans, that is used for paint exhaust tubes of motorcycles, that may be much better than stickers ..... don't detach, and resist to heat.

Also, a thing that is jumped me in mind right now ..... don't place modules under the cigarette, left some space there ..... it's always possible that tobacco pieces, ashes and so on, drop from the cigarette, when you put it inside, when become turned on, or when you remove it, and if this happens, is better that there's no modules on which that can fall