Need lens help for 405nm

[Elmojo]

Hi guys,
On a whim, I bought a cheap "100mW" blue (405nm actually) handheld laser from some random company in China.
It should come as a shock to no one that it isn't anything like the description.
It's supposed to be focusable, but the cap just unscrews and seems to have no effect on the position of the module.
There's no lens in the cap either, just a hole.
The module isn't attached to the body in any substantial way, it's just held in by spring pressure between the battery and the inside of the cap.
I know I'll have to fix that, if for no other reason than to wick the heat better.
I thought it might be fun to get a lens for it and see if it can be made somewhat usable.
I'm really not into burning, I'd rather throw a beam across the field behind my house and screw with the deer at the far woodline. :evil:
I'm just wondering if there's any point in messing around with it and trying to make it usable, or just chuck it in a drawer and chalk this one up to foolishness and (hopefully) experience.
Anyway, any suggestions or opinions welcome.
I can take photos of the unit if needed, but it looks pretty much like the one on this page, except the button is a little different and it's 100mW, not 200, as if that number really means anything.
Thanks in advance,
Elmojo

 

[Calarin]

That link doesn't work... you can purchase AR coated glass lenses for the 405/445nm diodes. Or you can get the lens pre-installed into a threaded assembly that goes into a standard Aixiz module (theres lots of sellers of these but ex: 405/445 Glass Lens - $6.25 : Mohgasm!, Because it feels so good.). If you don't know what an Aixiz module is, it is the copper piece shown here (Copper 5.6mm diode mount for AixiZ 12x30 case, AixiZ) that the diode is pressed into (the lens assembly is also part of that package as you can see) .

It all depends on the design of the laser host you have, so if that doesn't help, I would recommend uploading pics.

 

[Elmojo]

Really? Works fine over here.
Anyway, thanks for the lens info.
So basically, if I get that lens, and maybe the aixiz module if the mount I have can't be adapted to fit the lens, then it should collimate the beam and allow me to focus?
Sorry for the newish questions, I'm just getting started in 'serious' lasers.

 

[Calarin]

Yea it redirects me to Page Not Found - China Brands,China Wholesale,China Wholesaler,China Supplier,China Store,Cosplay Costumes,Drop Shipping,Free Shipping,Drop Ship,Unlocked Phones
ah well.

Well let me welcome you to LPF - I'm fairly new here as well! I've learned just a small chunk of what some of the other people on this forum have swimming around in their heads , but I'll just tell you what I would do from what I know so far. Oh, and there is a wealth of information on these forums, it's just finding it that is the tricky part.

If you have to switch it over to an aixiz module, chances are that after you take apart the host and remove the diode so you can press it into the new module, it won't fit back together in the host (unless theres a 12mm hole by chance from the old module).

So this quickly becomes a question of: just get the lens by itself and install it yourself provided you have a place to put it in, or do you possibly have to move the diode+driver over to a new host that fits the aixiz module? (like the cree aurora c6 flashlight with a custom heatsink)

It's up to you. The latter will definitely involve some soldering, and you will have to make sure the negative lead makes contact with the pill (which was tricky for me at first).

I would definitely try getting a lens in there first, and if that doesn't work, then go with the host conversion. I would purchase a 405nm AR glass lens assembly like the one I linked previously, and then unscrew the inside part so the lens comes out and try to fit it to your current laser host.

 

[Elmojo]

Thanks for the warm welcome, I was beginning to think no one would answer.
I'll get the lens first and tinker from there.
I'm no electronics whiz, but I am pretty handy with a soldering iron.
If I can't make that lens work with the module as-is, I'll either buy another one and do a diode transplant, or mod the one I have.
Thanks for the tips!

Oh, and I still can't figure why that link didn't work.
If you go to everbuying.com, it's item #58252

 

[Calarin]

Yea I can't find anything 405nm on that site lol - if you live outside the US, maybe that's why you can see them.

Good luck!!

 

[Elmojo]

That's really odd, I'm on the east coast US, and I go to that site all the time.
Did you try searching by the sku #?
Anyway, I ordered the lens from that site you linked, so we'll see if it helps.
Thanks for your help, I'll be sure to report back with any progress.

 

[Elmojo]

Well, I got the lens, and hacked up the module to get it installed.
I can now install the lens in various configurations, but none of them result in a "beam".
All my other lasers throw a more or less parallel beam, that only diverges a little over long distances.
This one is more of what I'd call a 'focusing' laser.
I can get a tight pinpoint and close range, say 2-4 inches, but it quickly spreads to look like it's projecting an image of Jupiter.
Do I have the wrong lens or ?
Also, I have to add a 3rd lens to get any sort of spot. Just the 2-lens unit I got from Mohgasm doesn't do it.
I was under the impression that a collimating lens system was to get the beam in a low-divergence state.
Apparently, I'm wrong on that.
Thoughts?

 

[Fretwrecker94]

...
I'm really not into burning, I'd rather throw a beam across the field behind my house and screw with the deer at the far woodline. :evil:
...

Shining lasers at animals is a big no no :tsk: ... they have eyes too. It's a life nonetheless. And I'm sure any walk of life values sight.

It's up to you. The latter will definitely involve some soldering, and you will have to make sure the negative lead makes contact with the pill (which was tricky for me at first).

Just a tip for further builds. Set it up fora case negative build. That way you don't need to have a wire making contact with the pill. Unless you're using a MicroBoost driver. Then it gets a bit tricky since you need to separate the grounds.

 

[Elmojo]

Shining lasers at animals is a big no no :tsk: ... they have eyes too. It's a life nonetheless. And I'm sure any walk of life values sight.



Just a tip for further builds. Set it up fora case negative build. That way you don't need to have a wire making contact with the pill. Unless you're using a MicroBoost driver. Then it gets a bit tricky since you need to separate the grounds.

The deer comment was just for giggles. I don't shine lights (laser or otherwise) at deer, it's illegal, and mean.
I don't know what that comment was for originally, it is case negative.
I don't have any wires going to the pill. Just the coil spring touching the positive on the battery.

I just noticed that the lens I ordered from Mohgasm was supposed to be a 3-element lens, but there's only 2 lenses in there.
Is that the problem?

 

[Fretwrecker94]

Haha good on you, mate. I'm not a hardcore animal rights activist, but I figure life is life and with power comes responsibility. :beer:

The case negative comment was for the other poster in this thread, Calarin.

3 element lenses have a special coating which defines it as "3 element", IIRC. It has nothing to do with the number of lenses.

Happy Lasing!
David

 

[Elmojo]

Haha good on you, mate. I'm not a hardcore animal rights activist, but I figure life is life and with power comes responsibility. :beer:

The case negative comment was for the other poster in this thread, Calarin.

3 element lenses have a special coating which defines it as "3 element", IIRC. It has nothing to do with the number of lenses.

Happy Lasing!
David

Ah, Gotcha, thanks.
I'm reading the threads in your sig. Gotta say bro, great work!
I plan to build something similar to your $5 CPU heatsink build.
I have lots of DVD burners and heatsinks laying around.
What speed burner is my best choice?
Now I just need to figure out how to build a driver...

 

[Ghostchrome]

3 element lenses have a special coating which defines it as "3 element", IIRC. It has nothing to do with the number of lenses.

The three element lens do have three pieces of glass that the light has to pass through. G1s and G2s only have two, which is why people like 'em so much... less glass for the light to pass through and less loss.

 

[Fretwrecker94]

The three element lens do have three pieces of glass that the light has to pass through. G1s and G2s only have two, which is why people like 'em so much... less glass for the light to pass through and less loss.

Thanks for the clarifications! Makes sense now that I think about it. Guess you learn more everyday!

Ah, Gotcha, thanks.
I'm reading the threads in your sig. Gotta say bro, great work!
I plan to build something similar to your $5 CPU heatsink build.
I have lots of DVD burners and heatsinks laying around.
What speed burner is my best choice?
Now I just need to figure out how to build a driver...

Thanks, I do fancy a cheap build that works from time to time. Anything over 16x is good. 24x starts using diodes that we don't have modules available for. I have a 4x diode from an ancient DVD burner. It's so antiquated that I held onto the diode for nostalgic value. Makes a nice spot at 83mA. Gives around 40-50mW. But now I'm rambling and off topic.

If you need any help on your builds let me know through PM's and I'd be more than happy to help.

 

[Elmojo]

So does that mean I have a defective lens and need to contact Mohgasm?
It only has 2 lenses inside, and does NOT focus the beam without adding the third lens.

Thanks for the offer of help Fret, I'll be taking you up on that shortly.
I have the heat sink, and I'll pull apart a DVD burner tonight.
Do I understand correctly that I just need to add a module to mount the diode in, a driver to power it, and a power source?
I guess the module has the lenses or no?

 

[Calarin]

Its called three element because the glass material is composed of a combination of 3 different compounds afaik. The g-1 and g-2 are single element lenses. The single will give you more output (up to 20% I think) but its much more expensive. You also get a finer dot with the 3 element. Both need two lenses I believe to focus into a dot

You should be able to screw the lens housing to adjust the focal point. you can focus the lensfor up close or for infinity by changing the distance. Also make sure it isn't flipped around!