Uniquefire UF-T20 mod: 3.05A xpg2-3C dedomed on Sinkpad

i have one with nanjg 3.05A dedome xpg2 r5 its very bright but i can not so precision focus like the smallsun c10

i have buy transistors for op to 4Amp

i have another pill with najg 2.8A with xre cool with: its not so bright.

Thank you for the pictures and modding idea. I have the same flashlight - maybe I will modd it a little bit, too.

Ok guys, I finished my first mod. With some tips from Djozz, the shopping list has been as follows:

- Wallbuys UF T20
- C8 brass pill from FT (and some silicone lube & thermal paste)
- Intl-outdoor: Noctigon XP20 MCPCB & CREE XP-G2 R5 3C LED and Qlite Rev.A 7135*8 3.04A driver

This week finally the FT package arrived, so I spend the evening modding this T20. Last month I've read many posts so I was well prepared :)

First step: chemical dedoming! I decided not to use gazoline but cellulose based thinner, learned from BLF member Toppel in this great post.

Within an hour, the dome fell off in pieces, as you can see in the pictures:

So, in my humble opinion thinner/cellulose is the way to go for dedoming, as it is clean and easy to use.

After dedoming I carefully installed & soldered the Led board and driver on the pill, and bridged the 4th star of the driver to ground for moonlight/low/mid/high switching options. Then I assembled the flashlight and hit the switch for some test shots.

Full zoomed in/out (mouseover):

My first impressions are mixed, see images below:

  • it's a powerful light, though I can't really compare the original T6 with the XPG2 LED
  • it gets quite hot after a few minutes on highest power
  • no blinkies is nice. Don't know if moonlight setting is useful.
  • the 'zoomed in' spot is not very consistent, it looks like a moon with darker areas. It's not a perfect circle and certainly not a sharp image of the Led dye like I can see with the SK68 clones.
  • when zoomed in, there's a large 'ring' noticable. I don't like that.
  • The light is quite yellow, compared to a SK68 Q5. Don't know if this is 'normal' or a result of the dedoming.


SPOT:

Annoying "ring":

SK68 clone vs UF T20 (dedomed XPG2)

The tint looks familiar, this what you get upon dedoming (warmer tint). It is just not fully focussed, mine does also not fully focus because of the thicker led-board and the dedome, but my spot is much tighter than that. Some people have reported issues with the focus of this light.

That is light gets hot is no problem, mine gets hot but hardly looses output, indicating that the led temperature is still fine.

The ring is the upper rim of the pill reflecting light, you get rid of that by blackening the side of the cavity the led board is in. Using a permanent marker already helps a lot.

Thanks Djozz, great feedback. I don’t expect thermal issues but noticed this compared to the default Led&driver of this flashlight. It may also prove that the thermal paste contributes in good heat dissipation :slight_smile:

With the default T6 led, the tint was much cooler, so I understand this XPG2 is warmer white and due to dedoming even more?

What can I do about the focussing issue and getting a tighter spot?

The lens needs to be a bit further away from rge led when zoomed in, perhaps an extra spacer of some kind where the o-ring under the lens is? You can start with loosening the lens a bit, or with a piece of cardboard to test how thick it should be, and for a permanent solution there might be a rubber washer of the right size in a plumbing store?

Strange. When you get it focused better, I wonder if the darkened parts will still be there. It looks like the emitter might have been damaged on one side, perhaps, or maybe part of the dome is still there on one side.

You could also examine it by putting it on moon mode, pulling the lens most of the way out to focus, and aiming a camera down inside to get a close-up picture of the emitter. You may also need to shine another light down inside, depending on how the camera behaves. I don’t have any zoomies with moon mode, but here’s a pic I got from that method with the light off:

(click to get even closer)

To me it looks like part of the dome is there, its effect could easily be causing those irregularities in the beam pattern (not the ring). Maybe you needed to soak for longer than one hour?

I sometimes take pictures of emitting leds through a cd (also good for looking at the sun during an eclips :-) )

Well, i'm focussed now :).

I have used an extra 'O-ring' of solid copper installation wire to adjust the lens a bit.

The projected picture of the die is not as sharp as my sk68 zoomy.

As you can see in the picture, the beam has a purple imperfection in one corner. Maybe the die is damaged, or its a little bit of the dome left on the die.

Well yes, maybe there’s a little part of the dome left. I don’t think soaking the PCB for a longer period would help, as the dome completely fell off and was kind of ‘crushed’, not dissolved. As the naked die is very vulnerable I didn’t brush the surface.

Well done! The blue in the corner is typical of a chip of phosfor broken off in the corner of the die during the dedome (you should be able to see it in a close up of the led), exposing the blue led underneath.

The image suggests that the led is not exactly centered under the lens.

Cheap glass lenses used in flashlights tend to do worse imaging than plastic ones. I still like them better because they do not scratch over time, and I do not want the ugly die imaged sharp anyway.

I think this is collatoral damage of dedoming then?

:) I'm fine with the picture. Ans the beam is small enough for me now.

or maybe cellulose based thinner is a bit harsh, I mean, full dedome in just an hour or less, that’s pretty fast chemical reaction.
Anyways, all those discolorations and unwanted rings are reason I don’t buy zoom light.

depends remains of silicone or around your LED?

I dedome with thiner and it works very well.

after the ball fell off is just lash out, blowing hard / blow / blow and back for an hour or two in it!
then back hard blow / blow BLOW … and you have a clean dedome.

the harder you drive up the Amp (4 or higher) clearer and more how you obtain whiter light.
furthermore, you can gently with a black marker around the silver plate LED colors around the LED itself to reflection.

The only thing I want with this flashlight is a spill from afar 100m + which is the same as the hub you have to + –10 meters.
if someone trick or another glass knows please replace. please let me know

and of course … of course even more light! :bigsmile:

another beam shot,

this time the modded Uniquefire uf-t20 VS a modded Trustfire X7, emitter : XP G2 R5 2B (with dome) at 5A current .

left: uniquefire , right trustfire

The Trustfire X7 should be at ~225 Klux.
What do you think guys? The uniquefire spot looks more intense, isn`t it ?

Solder paste? In the video it he uses ‘solder paste’ in the pill… I am not sure what this is, can someone send a link to where I buy… Maybe from the ebay?

This is only one of many places
clicky link

Go onto Ebay.au and search for “solder paste -flux”

be careful as there will be a lot of flux under all kinds of names mixed in the results :~

Cheers David

I have been using this without any hassle.

https://www.fasttech.com/p/1261003