Why can't I burn stuff?

[Xplorer877]

You do know that the glass lenses used with Blu-Rays will kill them faster, right?
It reflects the light back into the diode and degrades the Gallium Nitrade chip

BTW, with the plastic lenses, you can cut the hole bigger.

Actually the very next post I was reading talked about this. I didn't know that. But I see no difference. I've had the glass lens on it through two sets of batteries and it's fine. But I switched them just in case. I have seen people cut a laser hole in the black plastic holder, but it is hard to do it cleanly. But Ill try it. The glass lenses AR coated for red right? What's AR anyways? :-?

 

[Spyderz20x6]

[quote author=Spyderz20x6 link=1228345229/0#14 date=1229371370]You do know that the glass lenses used with Blu-Rays will kill them faster, right?
It reflects the light back into the diode and degrades the Gallium Nitrade chip

BTW, with the plastic lenses, you can cut the hole bigger.

Actually the very next post I was reading talked about this. I didn't know that. But I see no difference. I've had the glass lens on it through two sets of batteries and it's fine. But I switched them just in case. I have seen people cut a laser hole in the black plastic holder, but it is hard to do it cleanly. But Ill try it. The glass lenses AR coated for red right? What's AR anyways? :-?[/quote]
Try cutting it away with a razor blade, or a scalpel blade.
Yes, they are AR Coated for red.
AR stands for Anti-Reflective. Do, if it is AR Coated for 650nM, that means it does not reflect 650nM light.
That is why AR coating for red has a blue tint. It is blue because the blue is getting reflected back into your eyes...
Hence, that is why violet light gets reflected.

 

[OHNOITZALASER]

Ok so I tried a spanking new 9V, and it does melt stuff.

Just, it's very very hard for me to focus it, the light is so bright that every single dot looks big but occasionally I get it to a point where it's at its smallest (but its still about 3mm big), brightest, and I know that that's actually a pinpoint looking bright. At the point, things start to melt. Often, it has trouble melting anything and it takes me like 15 seconds to get something smoking. Maybe bad lens?

 

[kernelpanic]

Ok so I tried a spanking new 9V, and it does melt stuff.

Just, it's very very hard for me to focus it, the light is so bright that every single dot looks big but occasionally I get it to a point where it's at its smallest (but its still about 3mm big), brightest, and I know that that's actually a pinpoint looking bright. At the point, things start to melt. Often, it has trouble melting anything and it takes me like 15 seconds to get something smoking. Maybe bad lens?

9V batteries pretty much suck AFA lasers go. They just don't put out enough current for long enough. You'll be much better off using something that can draw more current for longer. Better combinations for the rckstr driver would be-

3- CR123s in series for 9V (or RCR123's for 10.8V)
3- 14500's in series for 10.8V
6- AA's or AAA's for 9V.

The middle option is probably the easiest to find a host for as the 3.6V 14500's are  the same size as AA and there's lot's of 3xAA LED flashlights out there.

In the meantime try using a lithium 9V. (Like this- http://www.radioshack.com/product/index.jsp?productId=2104692) It'll put out more juice for longer. But it's more expensive. (They're mostly used for smoke detectors because they have a very long shelf life...)

Hope this helps.

cheers,
kernelpanic

 

[john_lawson]

I have made several 9v powered types all being the reg 9v duracell and all burn well for at least 1 hour run time i made iewed one at 86 ma probibly 70 mw and it burned well

 

[kernelpanic]

I have made several 9v powered types all being the reg 9v duracell and all burn well for at least 1 hour run time i made iewed one at 86 ma  probibly 70 mw and it burned well

I'm not saying it won't work. I'm saying it's not optimal. Most builders here end up moving to rechargables as the performance is good and they are more economical. But it's more difficult to do this with blu-ray's than with other lasers because of the voltage requirements of the diode, especially when using a regulator with 2v dropout. My low dropout driver allows me to run my 405 off of 2 cr123's at 6v no prob, but I only use RCR123's as CR123's are $5 each.

Also because we're generally only drawing ~125-150mA for the PHR, one doesn't eat batteries as quick. If I put alkalines in my LD open-can red or my 50mW greenie, they go really quick as they both draw almost half an Amp. But my PHR draws only a third of that... So it's possible that fewer blu-ray builders go rechargable.

In any case, rechargables have saved me a lot of cash in this hobby.

cheers,
kernelpanic

 

[john_lawson]

;D agreed ;D

 

[Low-Q]

405nm is sightly harder to focus than other wavelengths because your eyes have such a hard time focusing on it so you find it hard to see if the dot is small or not.

-Adam

A good way to figure out if an object is right at sweet spot you can tell from how the reflected light is impacting on the surroundings. If not in sweet spot, the reflections has fine small dots dancing around the surfaces. If in sweet spot, these surrounding dots gets bigger. These dots are a result of interference from the monochromatic light which is reflected from a given area. The interference pattern you see in the reflections gets coarser the closer to sweet spot you get, as the area from where the laser ligt is reflecting from gets smaller.

So even if you have only one eye left, a very poor one, and extremely short-sighted, you can tell with 100% certainty when you hit sweet spot. Just make sure you don't hit your skin instead of other things. It HURTS, and smells funny!!

Low-Q

 

[Greenhorn]

[quote author=Diachi link=1228345229/0#6 date=1228434860]405nm is sightly harder to focus than other wavelengths because your eyes have such a hard time focusing on it so you find it hard to see if the dot is small or not.

-Adam

A good way to figure out if an object is right at sweet spot you can tell from how the reflected light is impacting on the surroundings. If not in sweet spot, the reflections has fine small dots dancing around the surfaces. If in sweet spot, these surrounding dots gets bigger. These dots are a result of interference from the monochromatic light which is reflected from a given area. The interference pattern you see in the reflections gets coarser the closer to sweet spot you get, as the area from where the laser ligt is reflecting from gets smaller.

So even if you have only one eye left, a very poor one, and extremely short-sighted, you can tell with 100% certainty when you hit sweet spot. Just make sure you don't hit your skin instead of other things. It HURTS, and smells funny!!

Low-Q[/quote]

I've seen that phenomenon, and I've also seen the patterns change due to the surface melting and changing how the light is reflected. It's pretty cool.

 

[marks47]

So even if you have only one eye left, a very poor one, and extremely short-sighted, you can tell with 100% certainty when you hit sweet spot. Just make sure you don't hit your skin instead of other things. It HURTS, and smells funny!!

Low-Q

Bah. A (tiny) laser burn is a burn of honor! (unless it's on your retina, of course) (Hey, you know, this forum, above all others, needs a pirate smiley. Or any other smiley with an eye patch)

Seriously, though. The cornea is what blocks most of the blu-ray laser light from reaching your retina. It's not "supposed" to pass light through until you get to 400nm minimum... Try as you might, you're going to have trouble with focussing.