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FrozenGate by Avery

So I dismantled a Curtis Mathes Blu-Ray player

J

journeyman

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Since it was a gift and unbearably (read: embarassingly) slow, I took it apart and harvested the goodies (motor, worm drive, micro screws, heat sinks, neo magnets, prisms, etc.) and was surprised by 2 diodes.
One is a 3 pin and one is a 4 pin.

Are they both violet lasers? Any way of telling how much current they can handle?

I plan on making a stationary unit (not a pointer) for a sculpture. I want a visible beam but I want it to stay on for hours at a time.

I'm a jewelry fabricator (well I have a dayjob doing AutoCAD) so I plan on making my own "host" etc. out of sterling since I have tons of it and can make my own tubing. (Silver is the most conductive metal so I figure that's an advantage, right?)

Any advice is appreciated.

FYI, metal conductivity goes Silver > Copper > Gold > Aluminum.
 





Only one diode would be Blu-ray & I'm afraid the beam would only be visible with some smoke or a fog machine. If its a sculpture then maybe a mini fog device can be incorporated.
High power green laser beams can be visible in a darkened room but our eyes are much less sensitive to Blu-ray 405nm.
Oh yea & don't try to power the diodes without a laser driver, you will kill them.
If you haven't already then read looking-build-laser-read-me.
 
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Welcome to LPF. Enjoy your time with us here.

From a player?? most likely the diode is not going to be as powerful as the diode from a Burner (recorder) drive.

Blu ray is near UV so not really the most visible color choice.

I have compiled a list of "must read" information, it will make your time with us more productive and pleasant.

Laser Resources (for n00bs and veterans alike!)

http://laserpointerforums.com/f36/looking-build-laser-read-me-47684.html

Sam's Laser FAQ (The Laser Bible)

Sam's Laser FAQ - Preface, Introduction, What is a Laser?, Safety

RP Photonics Encyclopedia of Laser Physics and Technology

Encyclopedia of Laser Physics and Technology - an Open Access Resource of In-Depth Information, Free Articles, Nonlinear and Fiber Optics

I have included a handy guide to assist you in finding what you need. ;)

search.gif
 
Thanks for the quick replies!

So what is the second laser I wonder..?

I do a lot of work with high power LEDs so I am aware of the need for current regulators (and heat sinks). I have an extra 350mA buckpuck driver with "external dimming" (ctrl/ref) I can throw a resistor on it and bring the current down as low as I want, but for future projects I've been looking into the LM317 route. Any reason why this wouldn't work?

I met a guy at a party a while back who had a definitely-visible-in-a-dark-room BR pointer he claimed to have gotten out of a player, either he lied and got it out of a burner, or he is over-driving the crap out of it?

As far as the visible spectrum goes, I would venture to say I'm more aware of this than most people, having done a lot with additive/subtractive color I have read tons about how rods and cones work. :yh:

As far as over-driving is concerned, is the issue heat (I can sink the crap out of it) or the actual circuitry not being able to handle the current, or a bit of both?

Yeah a while back before they changed the rules, my friend got a high powered green pointer from china for like $120, you can see the beam in my apartment during the day with the windows open, burns anything black...

Not trying to write a novel just giving an idea of my experience, since I am a noob here and all!
 
Hey,

He could have gotten it out of the PHR-803t sled which WAS a reader! This is the most likely scenario. They easily went to 100mw which could explain what you saw. (you can get them dirt cheap on this forum <10$ kind of cheap. :beer:)

The reason diodes die has little to do with keeping the case cooled. It is simply a case of how much on die optical power the crystal facet can handle before imperfections arise (are burnt in). These imperfections then spread killing the diode. In theory using a better less reflective lens allows for higher powers as all the "bounced" photons on a bad lens are bounced back effectively increase optical flux on the crystalline structure.

We have a couple guys on here with much higher knowledge of how diodes exactly die, they can go more into detail and probably use more accurate terminology but that is the gist of it.

LM317 is the way to go if you want a cheap driver, LED drivers tend to fluctuate quite a bit from what I have seen, though I am sure better ones exist than the ones I have played with. Still the LM317 driver will set you back 30 min worth of work and 5$ in parts. I strongly suggest going the LM317 way to keep your diodes safe.


Best Regards,
brtaman
 
You cannot overdrive a diode without limit.

Each PN junction has it's limit of how much current can it take.
Too much current results in oversaturation, resulting in COD.

350mA is too much for any 'available' diode, meaning for less than 100$ for diode alone... speaking of which, how are 8x diodes with prices and availability today folks?

Player diodes are generaly too weak, unless it is PHR 803T addondrive , common here, PHR diodes go up to 100 mW long life.

3 pin diode is bluray one, see the Metatopic under 'Experiments & mods' section for pinouts and performances.

4pin diode is red + IR diode used for DVDs and CDs.
 
I know 350mA is way too much, with the driver I have, if you put a diode across the reference/control leads it reduces the output current, resistance/50=% of 350mA output.
 
A little advice on making the host out of sterling :D I am also a jeweler, and have done so. first, make the threads on any screw parts nice and thick, Since the metal is so soft, and the threads are a natural weak point. So thicker = better, if they are thin, one single time trying to put it together not perfectly aligned will scrap them. If you are doing casting work, remember that you can cast with plastic as well as wax. So finding plastic items that have threads on, not only will give you an idea about how thick to make the threads, but you can simply modify the plastic to suit your needs, and add it to the wax :D Just make certain the plastic parts have NO metallic paint on them, as you won't get a clean burn out of it at that point.

Also, don't attempt to manufacture the module itself, as you need pretty damn good, if not perfect alignment for the optics. (read: really hard to get right in silver, and wear and tear on threads when focusing wouldn't be your friend). Your best bet is still an aixiz module, or a small brass module out of some other laser pointer. So get a module first, then build the host around it.

I am working on testing casting a brass module in place in silver atm, as it will provide perfect heatsinking from the module to the silver (no space between) however I won't be attempting it until late next week. Also results may vary, as most brass alloys don't have that much higher of a melting point from the average sterling silver. Also, if you are using argentium brand sterling silver, test electrical conductivity first. I haven't used it in my personal laser work, as I haven't had time to test if the germanium oxide that forms on it to protect it from tarnish is electrically conductive or not.
 
I'm amazed at the level of technical skill on this board...
I am using argentium primarily, but haven't tested its conductivity. I know it is supposed to be less but I figured it couldn't be much, I could be wrong.
My studio is currently set up for fabrication. I generally heat-harden before threading/tapping, as this does make it easier to do and the threads can take a little more abuse. I have assembled pieces with shakudo and that stuff is very soft.
Are you using any shield gas to cast the brass or do those casting alloys have tons of antioxidants? I've done some shakudo melts under crushed carbon, big pain.
I probably will end up using a module, but I'll at least give it a shot first. I do have a 10x stereoscope which never hurts. I'm not that stubborn, I just like a challenge.
 
Wonderful adventurous spirit there! :D I've never practiced with heat-hardening myself. So I've little knowledge there as to how much it improves silver. I might have to look into that a bit.

As for your question on casting brass, I was referring to casting the brass module in place like you would a gemstone. i.e. set in the wax, then ran through the burnout cycle in the flask. Not casting the brass itself. The module I used I found in a laser flashlight combo. The surface does tarnish some, however the part the molten silver comes in contact with does absorb some of the brass tarnish. This does add some impurities to the silver, however if you add a slight amount of fine to the mix first, it won't throw off your .925 count, nor does it impede electrical or thermal conductivity to any noticeable degree. Also, the very wax that you are burning out provides a strong reducing environment through the process. Just have to make certain the first flask you cast in the oven is the one with the brass inside, as once you start letting fresh air in, the reducing environment won't last long at all..
Cast in place with two metals together can be quite fun, and can really get your mind going if you haven't tried it before. Biggest issues are removing surface firescale from whatever went through the burnout oven, making certain you have good casting flow, as the metal inside is one hell of a heatsink, and poor flow in the cast always gives nasty turbulence porosity even if you get a complete fill, And the fact that the piece you cast in place will be 100% annealed....

At any rate, While I have not experimented with an aixiz module yet, my first test on a brass module cast in place worked out quite well.

Never tried shakudo. Only japanese technique I have dabbled in is mokume. Shakudo is copper with a touch of gold in the alloy right? Then worked to a patina?? hmm

Curious, where are you from? Utah here. Anyways good luck with your project. You will have to take some pictures when it's finished.
 
Silver host?? wow, now that's something. Laser Jewelry ... very nice combo I might say. I can barely wait to see the photos on this project. Good luck with it!
 
I've never practiced with heat-hardening myself. So I've little knowledge there as to how much it improves silver.
Click to expand...

That is specifically with Argentium sterling, afaik heating standard sterling is just a weak anneal.

I was referring to casting the brass module in place
Click to expand...

OK, gotcha now. I am more than familiar with the process, but currently I don't have a spincaster, kiln, or vacuum and since I don't really have a studio proper I couldn't easily use them right now if I did. I do have a staggering array of fabrication tools.

I made this ring a couple years ago when I was still at UH, its 10k and sterling silver, the 10k is cast in place. The stones are garnets.
ringsample.jpg


it won't throw off your .925 count
Click to expand...

So what if it does? We're the only ones that will see that part right? I think the fact that it is cast around the brass, there will be so much contact a little oxidation contamination isn't an issue.

Biggest issues are removing surface firescale
Click to expand...
Argentium sterling doesn't firescale. None whatsoever.

Shakudo was traditionally used in mokume for contrast, patina evoked via rokusho salts, now there's solution you can buy and you don't have to cook the solution up in a copper pot ad tedium.

OK so I think we've established we are both pros here.
Just to be sure though :) I did most of the laser welding on these:
Smith Gem Vault
http://www.hmns.org/files/marketing/GVAddlPhotoCaptions.pdf
http://www.hmns.org/files/marketing/gemvaultphotocaptions.pdf
 
journeyman said:
That is specifically with Argentium sterling, afaik heating standard sterling is just a weak anneal.
Click to expand...

I see. I was wondering. ty for elaborating. I've not worked with enough argentium to have found out about that.


OK, gotcha now. I am more than familiar with the process, but currently I don't have a spincaster, kiln, or vacuum and since I don't really have a studio proper I couldn't easily use them right now if I did. I do have a staggering array of fabrication tools.
Click to expand...

I see. I'm quite looking forward to your first silver host. It will be interesting to see the results. We have totally different productions specialties, as I do mostly casting. I do envy you your access to a laser welder!!! It's one "toy" I've wanted for quite some time.


Argentium sterling doesn't firescale. None whatsoever.
Click to expand...

I'm aware of this :D I was referring to whatever goes into the oven to be cast in place. It can be a problem sometimes. Argentium really is a wonderful alloy. I wish we could use it more at my work.

Some nice pieces you linked to there. I especially like the look of the silver/gold ring with the tsavorite garnets.
 
Correct, they are tsavorites!

I have found that the convenience of Argentium is worth the cost to change over to it entirely. The only problem I have is when I want to antique a ring, its resistant to Jaxx and Liver of Sulfur. Again, I don't know the conductivity of it, but it is supposed to have a higher internal resistance than standard sterling (making it better to weld). I'm hoping its still up there though.


I don't have access to the welder anymore. It was pretty sweet though all the variables to adjust, like the voltage, beam diameter, ramping, pulse rate, and several others I can't think of off the top of my head. The stuff you can do with it is crazy.

The ramping was the voodoo, I though. It seemed to me that the laser output was broken into three stages, and those stages could vary in output. As the laser flashed the metal, it would ripple out like a drop of water would and then solidifies. The ramping would change how the metal came up to heat and in turn how it rippled, and it would vary every alloy.

For sterling (no argentium there) you had to crank the voltage higher than anything else, so the piece would get hot fast, and if you hit the same spot twice, well the first one polished it, so the second one reflects right up under your fingernail!

It changed my perspective on lasers when it knocked a piece of silver out of my fingertips. I mean, since when does light exert force!?
 
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