Laser sight rebuild

[bhank]

My uncle is a gun collector and way back when he bout a 5mw red laser sight for almost $300 for his .44 magnum desert eagle. While I was visiting him we started talking about lasers and he asked me if I could do anything to make this one brighter and possibly a different color. Now the entire body of this thing is almost perfect for hosting a red or BR diode as its got a mounting hole for the original diode that is just a mm or so to small and needs to be bored out to fit but other than that its perfect. It would be difficult however to put a green module in it due to the restricting dimensions. I'll post pics soon. So now my question is would either an LOC diode or a green module be able to handle the shock of being mounted on a .44 magnum? Regardless of which one I use I plan to use thermal epoxy of some sort to not only transfer heat but also to keep the diode or module sturdy and help it stay rock solid in the body. So the only real question I have is whether or not the diode or module, which ever he chooses, will withstand the shock of being mounted on a .44.

Thanks
Blaine

 

[Mohrenberg]

thats a good question, we don't really know the kind of forces it would be hit with when the .44 is fired, g-forces from kick back, vibrations from sounds and firing.
I don't even think any tests have been done to see what kind of damage these diodes can handle.

for one, anything you use is going to have to be under-powered, as there is no room for heatsinking and it will need duty cycles of a couple of minutes probably....

any green module you use is going to be bulky, it's either going to be long (module and then battery) or fat (module with battery underneath).

would be easiest to stay with a red, although you need something to drive it, and i'm just going to assume that the stock driver on the 5mW sight is not going to be of much use...
your not going to have room for a rkcstr driver so you'll need a flex drive so that you can power it with one battery (3-5v) instead of two.

if you had access to a machine shop you could def. make something.......

 

[dr-ebert]

The diode die is very light - on the order of micrograms. Thus it has virtually no inertia and will be able to handle very high accelerations. The recoil of a gun isn't that much, in the order of 100g's if you hang it by a thread (a washing machine at 1000rpms generates as much ); much less in actual operation when you hold it. So it shouldn't be a problem.

 

[HIMNL9]

But be sure, if you want to use a green module, to get one of the "industrial" grades, where the crystal and expander are fixed using screws and alignment pins.

Cause 99% of the actual modules are built simply using glues, and 100G applied in shots on a brass crystal holder, can easily detach it from the glue in very few shots

For the red and BR, instead, being just diodes, no problems, just take care about the lenses (no spring fits, for keep them in place )

 

[Flaminpyro]

I recently repaired a 10mW green laser sight that I beleve had it's xtals missaligned as there is still a red glow like the LD is operating and still draws the same 350ma of current but no green coherent light comes out. This was a new wish module and had the xtals glued in and they still look ok to me but no real close inspection has been preformed. I replaced the new wish module with one from O-like we'll see how it works out.

 

[bobhaha]

either way... its going to be an awesome build.. as others have mentioned i would imagine that the forces aren't going to effect the diode too much..the module on the other hand might have a few probs.. post some pics so we can have a better idea!

-Adrian

 

[bhank]

Ok so here are some pics or the actual sight. The entire thing is made of aluminum so it already acts as a heat sink right off the bat . The last pic up there is the thing assembled, and the first pic is the thing completely disassembled. From left to right in the first pic is the lens nut, lens nut holder, area where i will press fit the diode (if my uncle chooses red), simple battery contact spring, main battery tube, end cap, and finally the pressure switch. In the fourth pic you can see where the diode will be pressed (again only if my unc chooses red). As I said in my last post the hole is MAYBE a mm or so to small and needs to be drilled out to fit. HOWEVER what I'm thinkin may be better is to machine a small adapter that i will press the diode into then press that into the hole in order to give it a little more stability, because that hole is very shallow (only about as shallow as the back plate on the diode itself). That spacer will give it a lot more stability and thats exactly what I need to keep the thing from being torn apart when the gun its mounted on is fired lol. Also if we go with red then I was planning on machining a custom lens nut that would hold either the lenses from an aixiz module OR a set of the high power glass lenses.

NOW, in the event that my uncle chooses green, I will have to bore out that same hole much bigger to accommodate the larger module. Also, from what I've seen in my adventures disassembling broken green laser modules, I figured I could unscrew parts and somehow surround the crystal and expander with some sort of epoxy that will dry rock solid and do it without obstructing the passage of light. This would help keep them both from rattling loose and destroying the laser. In the even we go with green I will cut a small cirle from a flashlight lens or something just to act as a dust cover basically in place of the lenses.

Either way regardless of which color we use I'm pretty sure I'm going to have to customize the battery compartment in some way either putting a spacer on the walls to make a smaller diameter or make a spacer for one of the terminals on the battery effectively making the battery longer. I'm thinking that either CR2s or CR123as will work the best judging by the diameter which is about an inch or so (I havent measured anything yet, still figuring it all out in my head and trying to convince a friend to give me some shop time haha). Anyway, as I go I'll post pics to keep everyone updated and please feel free to voice any opinions and/or suggestions along the way, I'd appreciate your help.

 

[bobhaha]

yeah it can be done! but ofcorse driver and batteries must be taken into acount! what power source does the original sight use? i would go with a flexdrive since its smaller and can run off smaller voltages! its going to be a pretty cool build.. but a bit chalenging.. if you cant do it your self i can reccommend some one who might be able to help you out (ask first)

link http://laserpointerforums.com/f39/laser-build-service-10-a-41549.html

hope that helped! -Adrian

 

[bhank]

The original power source was some sort of 4V battery I believe that had no button on either side just 2 flat negative-looking ends.

As far as the flexdrive goes, I'd prefer to make my own driver. Its not that I dont trust the flexdrive, its just a personal accomplishment thing lol. I like knowing I did it and its all my work ya know? To me it just makes it that much cooler haha. However I may just go ahead and use the flexdrive to speed up the process and make it smaller and simpler.

 

[bobhaha]

yeah i know what you mean.. i think those "flat negative-looking ends" are connected to a switch on the side of the gun.. the battery will have to be replaced... im guessint the 4v battery is the size of a AA battery.. is that correct?

hope it all turns out good! -Adrian

 

[bhank]

Well today I found out some bad news that could be good at the same time haha. I found out that I've got to have surgery soon that's going to suck and take 4-6 weeks minimum to recover. The good news however is that those 4-6 weeks will give me tile to work on a few laser projects I've had in mind, mainly this one with the sight LOL. So I hope to get a few projects done

 

[bobhaha]

Good luck man.. sorry to hear about your surgery.. is it for something serious?

 

[bhank]

Nah it's not serious. It's just a pilonidal cyst, Here is a link if you don't know what it is and actually care lol. This is the second time its happened and second surgery to remove it. Last one was 5 years ago and it was fine for a while then it just came back in the last 48 hours but oh well shit happens lol. At least I'll have time to work on my lasers.

On the bright side I also got a new job today lol so it all kind of balances out

 

[bobhaha]

lol... ok good luck! hope everything turns out fine!