Laser story with a happy ending

[AUTO XX]

A few weeks ago I was helping my girlfriend move into the house I just built for her. As always, I had my (1.49A so probably around 1.3W) 445 in my pocket.
Somewhere along the line I must have picked up something heavy enough to trigger the switch (I used a host that generally mitigates this problem).
Driving back with her it smelled like something was burning, we stopped, checked the car out, looked around for straw fires (when a farmer's baler screws up it is cheaper to burn the pile of straw than it is to try and re-bale it) but nothing was around.
I got home about 1/2 hour later and noticed the laser light shining THROUGH the pocket of my leather jacket.
I am one to take laser precautions very seriously so I was more than a little irate at the potential for injury but when I grabbed it, the thing was damn near on fire.
I had just charged the battery that morning (of course, it couldn't have been after using the thing for months without charging) so it was topped up splendidly.
It had burned through the pocket in ~4 spots and didn't look much like a laser spot anymore, more like a weak flashlight.
I chalked it up to "way too hot for way too long" and figured I would check out the driver to see if there was damage (I'm surprised the components didn't slide off the board on molten solder it was so hot)
and throw another diode in it.
I was checking it out today and it looked like there was melted plastic on the focus ring. Upon closer inspection, it is all over the lens as well.
When the leather was burning, it must have discharged an oily mist on the lens which of course baked on.
The laser had to have been on for over 30 minutes, it was easily 90+*C (couldn't hold it for more than a second without getting burned) and when I swapped out for a new lens, good as new....
These diodes are pretty damn tough.

I might keep the old lens for the pwetty star pattern

 

[rocket689]

Lol. I'm glad it was ok.
I often fear that my laser will switch on in my pocket and die from overheating.
I'm happy to hear you had a happy ending.

 

[AUTO XX]

Well, the clicky has a recessed position so it is the first time but I must have lifted something with the corner against it.
I was surprised how long it kept going actually, I figured the 18650 would have died long before that.
Any pressure testing I have done on the heatsink was with it in my hand, I guess being in an insulated, confined area is a little different. Yeowch!

 

[aryntha]

See, I'd be more worried about the heat's effect on a 18650 in your pocket. At that point the lithium ion is more of a concern than the laser.

That said I... do not keep any batteries in my lasers... YMMV on that but, my main rationale for that is some of the pictures I saw over on CPF when I used to haunt there (one could say I got more... focused.. ok that was bad) of 18650s that ended up "doing their thing" in a tightly screwed host.

18650s, CR2s, CR123s, just do not belong in a sealed metal container during storage...

 

[AUTO XX]

yeah, I popped the 18650 out with the help of a couple of dish rags asap.
I do keep batteries in my lasers though, the lasers are usually stored in the gun safe unless I have it on me.
Too many of my friends play with stuff I leave laying around.

 

[geeo]

WoW 30 mins thats one tough little LD alright

What host was it in?
Was the diode just in an AixiZ in the heatsink?
Did you have any other heatsinking on the driver other than thermal'd to the pil?

Lots of questions sorry I'm a noob to this

Thanks

 

[magmabeam]

Nothing personal, but you don't deserve to come out of that uninjured and no lasers completely broken.

Carrying a fully activated 1.3w in pocket while carrying heavy items? While your at it why don't do a Pulp Fiction and stick a pistol down that front of your pants with the safety off.

 

[AUTO XX]

This is in a custom heatsing I designed a while back, it can be on indefinitely as long as you are holding it

They are very complicated to make though because everything is press fit and even the aixiz has to be turned down to get rid of the chrome (I feel that it is a thermal bottleneck).
The driver(s) are pasted their own heatsink and that in turn is press fit into the main heatsink.
It is all made to tight enough tolerances that when you drop it into the host, it takes a few seconds for the air to escape around it.
That is why it can run as long as the batteries hold out, YOU become an additional heatsink.
Don't be sorry my friend, we were all new at this at some point. ^_^

@Magbeam nothing personal but you should go fornicate yourself with a wooden spoon.
Uninjured? If *I* was getting any laser energy, I would have felt it and shut it off. DUUH...
Completely broken? This design is damn near bombproof, ,the WORST thing that could happen is I would have to replace the driver, lens and diode. Annoying bu understandable.
There is an old saying you should remember:
It is better to remain silent and be a fool than to open your mouth and remove all doubt.

 

[geeo]

Yeah nice, that is indeed some heatsink. I like the idea of keeping the tolerances tight and a large contact area between the tube and heatsink. I'll be sure to keep that in mind if I ever make my own.

 

[jimdt7]

Glad nobody was hurt. I was amazed when you said that it still works.
These diodes must be really hard !

Jim

 

[ShortyInCanada]

"It is better to remain silent and be a fool then to open your mouth and remove all doubt."

Correction - It is better to remain silent and be thought a fool than to open your mouth and remove all doubt.
I grew up with an ugly version of that on my wall. My nasty mother would frequently respond to questions from us 3 kids by simply pointing at the sign. So as a kid I was taught to not ask questions...changed that habit as soon as I moved out !

Interesting how this thread was quiet for 2 weeks...

 

[AUTO XX]

Lol, I stand corrected.
Yeah, I thought this would be an interesting subject but no one saw it.
Good to see another Canadian on here, surprisingly few of us considering the lack of laser laws