Frankenstein 445nm 3.1W With LG Beam Expander (Recoated Lenses)

[Minamoto Kobayashi]

Another day, another project better redone :beer:
This time is my pleasure to introduce You the deadly NDB7875@3.1W with 405 G-2 lens and the modified LG beam expander.

The parts:

Diode in full copper module wrapped in a 0.05mm indium foil:

Diode carefully inserted in a satined aluminun heatsink and locked by a side screw:

Diode+heatsink inserted and blocked in the head by a threaded bezel:

(full resolution pic here: http://imageshack.com/a/img673/3148/yO8qe3.jpg)

The back side:

(I put also 4 small drops of Arctic Silver glue to enhance a little bit the heat transfer in the not-contacting part)

* UPDATE 08/07/2015 *
Since I discovered that the indium foil was ruined during the diode insertion (the indium foil is very delicate and works very well if pressed between two flat surfaces, while it tends to ruffle if crawled), I wrapped the copper diode case with barrel with a very thin and malleable 0,04 mm copper foil and inserted it with noticeable pressure into the aluminum heatsink hole.
I done also an extra small heatsink glued with Arctic Silver thermal compound to the main heatsink. Over this heatsink I glued with the same compound a lot of 0.04 mm copper foils as a sort of accordion, so when I lock the main heatsink, the "copper accordion" touch with enough pressure the other big aluminum driver heatsink inside the Frankenstein host. In that way I will have a nice cooling help.
In about 2 minutes the whole head become warm, so this is the proof that everything works fine :beer:

Driver @ 2.4A glued in the internal heatsink thru Arctic Alumina thermal adesive:

Side B of the internal heatsink:

Side B of the modified pill:

The pill inserted and locked with a gold plated neodinium magnet soldered on the top of the spring to enhance contact:

The modified battery holder (with two original Enerlion 3400 mAh protected cells):

The modified battery holder (with a dummy aluminum cell):

(the dummy cell was made with the help of a lathe. I ordered an original
Enerlion stick for free from the company were I bought the cells LOL )

The assembled host:

(The power noted in the label is wrong because it was created for the Frankenstein 1st edition LOL)

Laser with modified LG beam expander mounted on a Pedco Ultrapod II with Manfrotto superclamp:

(full resolution pic here: http://imageshack.com/a/img633/7158/48DwRy.jpg)

(full resolution pic here: http://imageshack.com/a/img540/5771/Lm4TyH.jpg)

The 2 mins performance without beam expander:

The 2 mins performance with beam expander:

The 2 mins performance with beam expander (after 5 mins cooling in the freezer LOL ):

The devastating power of a very tiny beam:

Conclusions:
it is not the most powerful laser in my collection but surely the most impressive.
The beam expander allow to create a small concentrated line even at a distance of 50 meters, so it is able to start smoke on wood or start fire on dry leaves. Very scary and dangerous weapon. :gun:
Also using high quality cells (3400 mAh Enerlion - Samsung protected cells), the laser has little autonomy: after 15 minutes of use rests only 1/5 of
capacity left!
After 2 working minutes the heatsink become warm, so I prefer maintain a max of 2 minutes duty cycle, at least in Summer time.
Thanks as usually to DTR shop for the items and to Mr. Jayrob for his craftmanship :beer:.

 

[Cel]

Re: Frankenstein 445nm 3.1W With Lenses Recoated LG Beam Expander.

Nice laser, however it should go into 445nm section. :beer:

 

[Minamoto Kobayashi]

Re: Frankenstein 445nm 3.1W With Lenses Recoated LG Beam Expander.

Apologize for the mistake. I hope that a mod can move the thread in the right place soon :bowdown:

 

[10fenny]

Re: Frankenstein 445nm 3.1W With Lenses Recoated LG Beam Expander.

Badass!!! Where did you get the full copper module? and where did you get the dummy cell? I've been looking

 

[Minamoto Kobayashi]

Re: Frankenstein 445nm 3.1W With Lenses Recoated LG Beam Expander.

Hello.
I bought the diode already pressed in a full copper module from DTR shop.
I created myself the battery from an aluminum bar with the help of a lathe, but I remember that there are one or more LPF users that can build a cheap dummy battery for You. I do not remember their names, sorry ....

 

[DTR]

Re: Frankenstein 445nm 3.1W With Lenses Recoated LG Beam Expander.

The Frankenstein lives again. Awesome build.:beer:

 

[Pman]

I would just call it Frank for short Pretty interesting design. I thought from the first pic that the BX was a matched color but it doesn't look the same in the finished pic. I must be missing something or its a lighting trick. Anyways congrats
Sorry, got to spread some REP around.

 

[Minamoto Kobayashi]

Yes, it was a lighting trick: the first shot was done at 2AM in my lab under a 6500 lumens flashlight LED illumination, the lasts two shots were done at 7.30 AM under my porch during the first summer morning lights

 

[gozert]

Very nice build! I gotta admit, your builds just never seem to disappoint. You never forget even the smallest details and always add something special in it. Like you did with the beam expander this time.

 

[Minamoto Kobayashi]

Thanks a lot for Your nice words, but surely Lazereer beat me 10-1 about the details matter!
For example, take a look here:

http://laserpointerforums.com/f42/488nm-direct-diode-20mw-cni-pgl-iii-c-custom-build-88160.html

<no comment> :bowdown::bowdown::bowdown::bowdown:

 

[Pman]

I forgot to say that Indium foil is interesting. Looks to be quite expensive for some very thin stuff. I use pretty thin copper sheeting to make up for spaces at times but I don't think it's near as thin as what you have. You can take pieces of it though and push it between things to slightly shift or tighten pretty easily. Looks like the Indium foil may be too thin to stay together if I tried to push it in from the edge rather than wrap like you did. Don't remember seeing someone use that before.

 

[Minamoto Kobayashi]

Yes indium is not cheap, but with an indium foil You can wrap a lot of diodes .
Lazeerer used a small piece of indium foil in my c-mount red diode laser, that it is the normal use of the indium, between two flat surfaces.
In this case it is very difficult to insert precisely the diode wrapped, because it's enough to found a little imperfection on the surfaces to rip or curl the foil ...
I tried also with copper, but it is too thick.
I tried also with gold foils, but they are too thin and they are not easily machinable ...

 

[TaterMay]

I'm interested in the beam expander, as I, too have a 3+ watt NDB7875 that I would like to focus better. Where did it come from?

 

[TaterMay]

Also, is the video of it burning from the 50 meter distance you mentioned?

 

[Minamoto Kobayashi]

Hello.
The beam expander that I used is expensive:

https://www.laserglow.com/ADR#

Please remind that this BE is coated for 532 nm, so You must first decoat the original coating and then apply a new coating for the frequency that You wish.
It is not simple to do this, You must go to a specialized company also because:

- The big lenses are blocked to the thread with a strong glue;
- The small lens is inserted with pressure;
- The lenses needs to be boiled at 100° with hydrocloric acid for about
1 hours and issues may happens (lens ruined or pieces of the coating still adhering).

I ordered a new set of lenses with no coating from a specialized company here in Italy for my 3 LG beam expanders, because to apply a new coating in a virgin lenses I surely obtain much better results (major power output and less reflections/aberrations/imperfections around the dot).

In my video the lasers was placed at about 2 meters.