Need help picking which XP-G2 to dedome on ebay

Flashlight Modding and DIY Parts
1

I want to make a thrower with a XP-G2 Led
I read about the tint turning green and stuff if I dedome neutral/warm emitters?

First one: This is the cool white R5 bin, but I dont know the tint
Second one: This is the WARM white one, and I also dont know the tint

The reflector I will be using is a: I think this is a 42mm reflector
I have looked countless pages of ebay and google searches on places where I can buy PARABOLIC REFLECTORS, but I swear this is literally the only thing I can find! I need help!

My DIY driver is just going to be purely x6(?) Amc7135 chips in parallel 2.1A? (maybe 3A or 4?)
Is this even allowed? Do I need a diode/resistors?? or some other stuff that I normally see on drivers? I already made one flashlight driver from x8 AMC7135 for XM-L2. It works like a charm, but am I missing something that is important here?

I am new to DIY flashlights, but I LOVE THIS STUFF! I want to learn as much as i can

I made a 100W flashlight powered by x24 18650’s if anyone is interested I can show some pictures :smiley:

2

Welcome!

If it's an R5 it's most likely a 1A tint, since that seems to be the most popular. The XP-G2 emitters don't seem to get as much yellow/green shift as the XM-L2 emitters do when dedomed, so you'll probably be OK regardless. It is strange to not list the tint bin.

The warm white emitter listed is an R3 bin, which means that you will end up losing quite a few lumens vs. an R5. It will also end up very warm after being dedomed! I'd pass on that one for dedoming, especially since you don't know what tint you're starting out with.

If you want to maximize the output of that XP-G2, I would think about getting one (or reflowing that one) onto a direct thermal path MCPCB. It makes a huge difference at 1.5A+.

3

Welcome to BLF !

This is the best XP-G2 you can find : XP-G2 S2 (highest bin) on noctigon its 2B tint so you should get a neutral light after dedome.
You need a copper sinkpad like the noctigon for achieving high power

4

Because of how much money I have, Sinkpads/copper are out of my reach. Do you think sticking to 4x 7135’s (1.4A) is good enough for that cool white emitter?
I literally solder my amc7135’s to a thin copper sheet that I found. Am I doing anything wrong? I am just worried I might be producing too much heat or some kind of back flow? missing capacitors inductors? I am not sure. I just need a little advice on using only 7135’s by themselves. ( I got 30 of them on ebay for 15cents each)

I forgot another question, If I want a tight beam with 0 flood/spill? do I also put on a aspherical lens on top of that reflector too? I have seen some bean shots of xpg2 flashlights and they are so cool!

5

WWOW 4$ + free shipping on S2! this is a great website. I thought Ebay was my only option. thanks!

6

I don’t know about your driver but the LED can take up to 4 amps if your light has enough heat-sinking power.

Yes you only need aspherical glass for that, no reflector is needed, its like a laser beam. You can get the maximum throw with these kind of lights !

7

It would be best to not use a reflector under the aspheric. The light bouncing off the reflector will mess up the tight beam if you use just the bare dedomed emitter under the lens.

8

I got sinkpads for $1.75 a piece on ebay (you just have to look for em)
$1.85 now

9

:beer:

10

Yes,

With a reflector under the aspheric you’ll still get the exact same brightness spot… but it will be surrounded by a “donut” shaped image of the reflector. Even worse, this image will be focused… so every scratch, ding, spec of dust, or orange peel texture on the reflector will be visible in that donut.

The donut will be much dimmer than the image projected by the aspheric, so in some cases it can be helpful: it may be too dim to mess up your distance vision in spot mode, and if the light is a zoomie that can cycle to flood mode, it may give you a substantially brighter floodbeam.

11

Thanks for the help guys.



(Hot glue is not touching heatsink, heatsink is isolated. (;

I finished my light, and now I need help on which aspheric lens to get.

Right now, I have 3 lens.

The small lens produces 4x larger images compared to the other 2 larger lens


Text: The two larger lens’ image.

The small one (23mm) is a plastic lens that I got from an ebay flashlight.
The other 2 large ones are aspherical lens that I got from ebay recently. And their images are 1/4 the image of the smaller one.

I really want to have the properties of the larger ones, but in the form of the small lens!
I am guessing the small one is convex lens?
I looked up some lens I could buy.
one
two
three
four

Base on the pictures, they look very similar to my small one, but I am guessing it is hard to tell the difference between aspheric from convex when the pictures are at an angle + so small.

Does anyone know what I should do about convex/aspheric/small lens? Thanks!

12

It’s because compared to the small lens, the LED is big, and compared to the big lens the LED is small.

13

Do they have lens that sacrifice lumens for the same effect? Like a big lens but grinding down the edges so is it small again? Idk

14

I just found out today, the big lens have a longer focus, and the small one has a shorter focus.
Long focus, smaller image/ Farther away so, less light is captured
Short focus, large image/ Closer so, more light is captured