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How To Turn a Mini Maglite Into a Laser
Lucas123 writes "Using the laser from a DVD burner, this instructional video shows you how to create a hand-held laser that is powerful enough to light a match and pop a balloon. There's some soldering involved and the Maglite's bulb housing needs to be drilled out to fit the new laser diode, but with some basic skill, most people could do this. Just plain cool." Update: 07/09 12:23 GMT by KD : Warning, the device that results from following these instructions will blind you if you look into it.
Mounting the laser could be a slight problem if the shark is conscious
Just turn the shark upside down before mounting, that makes it go into tonic immobility for about 20 minutes.
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Re: Is the metal housing really necessary? ....Yes, for the most part.
....Mine didn't work because I could not find a way to get the laser diode out of the original steel heatsink it came in. It was glued inside a hole about 6mm deep in a odd-shaped steel heatsink. You could maybe grind the heatsink away a bit at a time with a Dremel & cutoff wheel, but laser diodes are sensitive to heat, so you cant let the laser get too hot. I tried using mine still in its heatsink with other optics (telescope objectives and whatnot), and with those set in front of it, it would melt a garbage bag a little but wouldn't do much else.
I tried this some time back, and it didn't quite work, but I'll relate what I know anyway:
1. There's TWO laser diodes in a DVD burner--remove them both out carefully, preserving as much of the leads already-soldered-on as you can! The leads of the laser diodes are very short (maybe 2mm) and only about a half-millimeter apart, it's damn tough to get the longer leads soldered back on if you cut them off, and there's no need to cut them off and then attempt to solder them back on anyway.
2. Inside the DVD burner you will find TWO laser diodes, with mirrors that feed them both into the same beam. Each will be glued inside its own heatsink, a piece of metal that may be a very odd shape, and then these are attached to a bigger copper plate. To tell them apart, just test them--try applying 1.5V power to both diodes one at a time, the CD one is IR and won't appear to do anything. The DVD one will light up visible red. (if all the lenses are removed from them at this point, you cannot burn your eyes out, that's in the next step...)
3. The bare laser diodes don't put out a laser "beam", they just create a pinpoint light (that's safe to look at!). To get the beam, you must mount a fisheye lens with its concave side set very close to the diode, almost touching it.
4. The laser housing is a metal tube with a fisheye lense set in it. The laser diode will get warm with 1.5V on it, and will get too hot to hold in ~30 seconds with 3V on it. The laser housing serves partly as a heatsink, and also as a way to hold the lens without melting (the DVD-drive optics will have a fisheye lense, but those optics are usually set into little plastic frames, and they may melt in this use).
IF you manage to get one out and do this, don't run it for more than ~20 seconds at a time without letting it cool down for a minute or so. The laser diode will work with 3V batteries hooked straight to it, but you're definitely not going to get that 100,000 hour lifetime. You'd be lucky to get 1000 hours. The DVD laser output power is typically around 210mW, and more than 150mW is enough to burn stuff (the CD laser won't burn stuff because it's only around 40-50mW max).
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