200mW green keychain buddy

[liveforphysics]

Hi guys, I know I haven't been around for a long time, but I decided some of you might like to see a project I made a while ago.

It's also good to see that my "Ellaser" idea is still getting used.


So, to get started, I wanted a powerful laser with me everywhere I went, but I didn't like lugging one with me. I first made a single RCR2 powered 200mW red laser that was about 2" in total legnth. It was an interesting novelty, and the beam was mildly visible in the night sky, but I missed the visibility of the green laser for long range pointing purposes.

So, I remembered that i had purchased 10 of the deal extreme "200mW" lasers, and 8 of them were still just sitting in my flashlight stuff box. I loaded them all with new lithium primary cells. One of the lasers had a clear cut brightness advantage over the others. I decided to use this one for my project.

Looking at the size of the pen style pointer, I knew what a bulky item it was to carry. Also fairly heavy for a pen style pointer.

I first thought I would need to somehow shoehorn the guts from this pointer into something like a single AA cell flashlight housing powered by a single half AA cell. I know this would be possible, but it would also take at least more than a few hours, and I didn't want to spend that much time.

So, I decided to see how the laser performs when powered by a single 10440 Li-ion cell. Well, I gotta say it does awsome! Compaired with 2 new lithium primary cells, the laser is signifigantly brighter! The driver board also gets warm/hot very quickly.

So, to cut to the chase, I shortened the package of the laser as small as I could go, heat sinked the driver board to the brass tube wall with thermal epoxy, thermal epoxy'd the LD back plate to the LD houseing, and thermal epoxy'd the laser houseing to the inside of the brass tube once I had everything worked out just how I wanted it.

I did this about 3-4 months ago, and aside from scratches and nicks that I really don't care about, its been a handy tool that hardly is noticed in my pocket. It's also been cheaper to feed with the rechargable 10440 cells vs buying bulk packs of lithium primarys.

The little red rubber cap is my favorite part! The electrical tape around the tip is to ensure the cap has a tight fit. The cap works as a saftey to prevent the beam from hitting something I don't want it to if the button is accidentally pressed, AND the button keeps the dust and pocket lint off the lens. I also ground the switch button down to be slightly under flush with the wall of the case to avoid accidental button triggering when it jingles around in my pocket.

It's brought laser convience to a whole higher level for me. The laser beam is brighter than other lasers I've bought for 4 times the price that never get used because they are not handy to carry or use due to size and goofy switching functions.

Cost of mods:
Artic Silver epoxy and a 10440 (both items i have loads of laying around) $10

Time to mod: About 1.5 hours for the first time, I could do it in half the time now that I figured out what to do.

Here are the pics.

And of course a beam shot pic. You can see it has a little bit of dust or something on the lens when I took this picture. Foruntately with the exposed front, cleaning is a snap!

 

[chimo]

Hey, that's interesting. I did a similar mod . Good stuff!

I see that you had to ditch the clip as well (mine would hit the button). I noticed something in your third photo that you may want to be concerned about - the ring attachment. It lookks like you can see the side of the 10440 Li-ion in the pic through the ring attachment/clip slots. Since the case is connected to the battery anode/positive in this laser, I would be concerned that the ring would eventually wear through the thin blue shrink-wrap on the battery and potentially (no pun intended) cause the battery to short out (it's negative/cathode under the wrap).

Paul

 

[liveforphysics]

Good work ChiMo! Looks like we were thinking along the same lines.

I love your username! LOL! I love to call my co-workers chimo's. They never have figured out what it means...

 

[BrokenR1]

Very neat! I have one I want to do that with now. I'd use it alot more if I actually had it on me. Do you have anymore pics of it apart and what you did? I don't hae any epoxy or 10440's so I need to get some. How do you go about shortening the length and have you measured it down to exactly how much?

 

[laserblue]

Yup very neat work

 

[nero_design]

Eep! Last time I pointed just a 'measly' 100mW laser at a flat screen, the LCD pixels were damaged. Congrats on the mini monster though! Very impressive at the output you have.

 

[liveforphysics]

Just wanted to share that I have passed the 2 month of daily keychain carry duty now.

The keys have been dropped a fair number of times, been exposed to rain, pocket lint, vibration and getting twirled around my finger when bored.

The black case has a couple of small chips in the paint where the brass is visible (not a concern to me).

The laser and all optics are still as perfect as the day I made it. I've now done a full 1minute run on a fully charged 10440 cell, and the laser case got warm. Since the case got warm, that tells me that the artic silver epoxy is doing it job and drawing that heat away from the laser.

I think the optics and alignment all being good still are due to the red rubber cap. I highly recomend everyone put a cap on the end of their laser. It's an excellent safey improvement against accidental firing, it seals all dirt and lint from soiling the lens, and it acts as a cushion when dropped on the tip.

Thanks for all the positive feedback on this thread!

Best Wishes,
-Luke

 

[dr_lava]

Hey, nice job. I hadn't seen it yet, but good work. I have a few of those exact red caps here.. they go on the probe ports for an axoprobe headstage.

Where did you get yours?

 

[attowatt]

Eep! Last time I pointed just a 'measly' 100mW laser at a flat screen, the LCD pixels were damaged. Congrats on the mini monster though! Very impressive at the output you have.

OT... but you are saying that if I point my 100mw greenie at an lcd screen, it will damage pixels on screen?

 

[stephenmadpotato]

Eep! Last time I pointed just a 'measly' 100mW laser at a flat screen, the LCD pixels were damaged. Congrats on the mini monster though! Very impressive at the output you have.

That makes no sense at all. 100mw is not powerful enough to melt it, if it was then wouldn't sunlight destroy it too?

 

[Athoul]

100mW is more then enough to damage it, keep in mind that a collimated 100mW beam which is green will have a dramtic effect on dark objects. Sunlight is not collimated nor focused to such an energy density (normally). If you took a lens and focused sunlight onto your LCD screen, then you would probably have damage occur as well.

 

[nanoWatt]

I am not sure how a small keychain can produce 200mW of green power. A real 200mW laser with electronics should be the size of a mid to large flashlight. I can get a similar beam in the dark with my 5mW, so I'm a little confused here.

 

[dr_lava]

its output isn't 200mW green. This laser was just built using one of the cheap '200mW' dealextreme lasers, which have a overdriven 3-500mW pump max, and put out less than 100mW.

 

[Aseras]

With lithiums I can do 180mw of green on the DX200 ( and still to this day it's going strong ) back when we first discovered them here on the cpf. ON nimhn mine is still over 120mw.

The diode is a ~1watt 808 diode ( measured 980mw ). The biggest problem is that you really need to use lithiums are nimh to feed the thirsty little guy enough current. alkalines just don't cut it and this laser eats them.

 

[dr_lava]

Interesting. what's the current draw and what's the diode case? 9mm? I wonder what is their lowest level of laser that still takes a 1W diode.

 

[Aseras]

I'd be glad to tell you but I filled the entire top half of the laser where the circuit board is with high temp hot glue since I got tired of resoldering the legs to the diode because the board bent and cracked the solder pads when you pushed the button.

If it had the little plastic sleeve like a ledlight it would be great. Stock, the board just floats there in air only connected to the legs of the diode with no support ( i don't count the flimsy spring that nearly shorts out the bottom of the board that I removed ). After a handful of uses the board bent enought that the button would fall inside the case.