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

luminarium iaculator,
For now, i will not dedome the XP G2 2B in the Trustfire X7.
I bought the X7 to mod it into a aspheric thrower with a hard driven XP-E2 + 75mm lens . The XPG2 is installed now just to see how it shines with it, until my new lens arrives.

I want to report about the kaidomain 80mm aspheric lens link
This lens is not good for maximal throw, it has a bright spill and it can not focus all the light in the spot.

This is how the recycling light collar custom made for the Trustfire X7 looks :

Looking good that collar... Why would you not sell it to people? This is budget forum so you could make something with acceptable price to us and earn some $? I am first on waiting list...

Do you use welding mask when centering this collar? Or maybe moonlight mode only? I would have to use some eye protection for this because I mostly have single mode drivers.

Yes indeed XP-E2 R4 from IO are cool white with 1C tint(a bit greenish tint)...

Night picture taking is hard and with phone camera even harder so I should not judge the picture.

Illumination supply carries XP-E2 with 1D tint if you want to try something similar...

I don't think Andi gave correct data... It would be lucky if it throws 300 kcd with driven XP-G2.

"I bought the X7 to mod it into a aspheric thrower with a hard driven XP-E2 + 75mm lens"

Tried that in Xsearcher aspheric and if you find good aspheric it will be true laser like beam( I don't like it since it is smaller and I got even lower results than with hand selected XP-G2 2B (the brightest out of 20)

My advice is:

- No point of driving XP-E2 more than 2.8 A (no results and heat will be enormous if you will tune it up with more chips)

- Stick to newest XP-G2 S2 (brightest XP-G2) and order at least five pieces and select the brightest of them(you will surprise how much lux you can gain with right selection of emitters)

This is mine 450KCD(with lower performing brothers I had from 380+) Xsearcher with hand selected XP-G2 R5 2B driven at 3,6A heavy fog( I don't want to tune up further because it is single cell light)

I will try to made XP-G2 S2 1A (which should outperform this setup up to 10% or more if I find brightest among lot of them because 2B is in its upper performing class. If you don't understand what I talking about read here about led bins and performance deviation http://flashlightwiki.com/Cree )...

In fact I have 6 pcs of them I am just to lazy to start...

Looking forward for your build but I think it will be extreme hard to find good aspherics for X7. Good luck.

Tint graph:

Yes, i centered the collar using moonlight mode.

Recycling light technology is patented by Wavien and start selling the custom collars here would probably be like calling for trouble.

It would be nice if somebody that understands exactly how the law works in this case would step in and explain if there is a way of selling the aluminium collar clone without getting in trouble.

Nâh, it’s unreasonable to patent properties of light (i.e. laws of physics), so f*k Wavien, and f*k LedLenser while you’re at it.
The nerve of some people… I mean really…
Inventions are usually discoveries anyway, so there.
:slight_smile:

I was looking for a picture here of the main tube, unmodded, because i just modded mine, taking care of the focussing business.
But i don’t have the ‘before’ pic…

So, I have a UF-838 that I was going to put a de-domed XP-G2 in with a 3.04A Qlite / NLITE driver. But it has a hollow pill and I haven’t had the motivation to build a heat sink, and it has a rather long focal distance so it’d probably lose a lot more lumens than necessary when focused. My estimate is that it’d max out at about 60 kcd, based on holding the optics in front of another de-domed XP-G2 I have and measuring it.

I’m thinking it might be a better idea to just buy a UF-T20 to mod instead, and keep the UF-838 as a flooder. In wide mode, its lens is only like 1mm away from the emitter, so it has an extremely wide beam. Great as a “flash” for photography, but not very useful for anything else.

The goal here is to make a pocketable aspheric thrower for entertainment purposes. I don’t need 200+ kcd of throw, but I wouldn’t mind getting as much as possible out of something the size of a C8 or smaller.

Any thoughts on the best approach here? I currently have the UF-838 and de-domed XP-G2 on a 20mm star and a replacement 17mm driver and a dummy plate to mount the driver in a 20mm hole if necessary. Just not sure if I should grab a UF-T20 too, or just find and shape some copper to jam into the hollow pill and use the parts I already have.

Hi

I’ve got a uf-t20 with dedomed xp-g2. It has additional copper in pill and spring mods.I just put in a fet driver by adding a fet to a 105c like comfy chair describes in one of his posts (but not same fet, but similar specs). Now I’m thinking I’d like to see what it is like with an XML dedomed. But I’m concerned with this driver it could blow the led with a inr 20c. Could it blow the led or am I worrying for nothing?

Thanks.

The XM-L2 has a lower voltage at a given voltage so it will draw more amps, if all is done well, as it seems, you could get 7A or so. I assume a direct thermal path copper board, clamped or soldered well onto the pill? Then it should work alright. The light will get hot, but it will handle the heat, at least for the first few minutes.

I would put in an xm-l2, but only have xml on hand. Yes sinkpad, but attached with fujik. So even though the driver is capable of 10amps+ (what I have measured with basically the same driver on an srk), and the battery is supposed to be able to do 15amps, something stops it going to these levels? Sorry if that’s a dumb question. I’ve tried to read up and understand, but not quite there yet.

The XM-L has a slightly lower voltage than the XM-L2 but that should not matter much. The current is limited because a)the XM-L2's voltage at 8A is already 4.2V, add up the various small resistances in the rest of the system and you will only end up with lower current that that, b)even the best high current battery will not be able to maintain its 4.2V voltage at higher currents (see the various HKJ battery reviews). So no worries, it will be even a challenge to get it over 6A.

Btw, try to make the fujik layer as thin as you can get it, getting as much as possible metal-metal contact.

This is something you made? Do you have a thread about it? Have you tested the actual ouput results using this collar vs a Wavien?

What’s stopping it is the Vf, while in a multi emitter/multi-cell setup the FET drivers can do up to the maximum rating of the FET / cell combo however running that high the Vf is the limiting factor in a single cell setup. Most of us see sound 5-6.5A (out of the best 4.2v INR cells like 25R’s and VTC5’s) to a single XM-L2 and about 5-5.5A to an XP-G2. You will need to use a buck driver with higher input voltage to get above that, it’s just not possible with a linear setup cause the cell can’t support the increasing Vf.

From 4.2v in (using 4 Parallel 25R’s in an SRK) the highest I’ve been able to obtain is 21A to 3p XM-L2’s (which averages out to nearly 7A per emitter plus a little burn off). I do not believe anyone has been able to get a linear FET driver to do above ~7A per 3v emitter tho there are several buck drivers that can run a 3v emitter at >8A. I have a few 6v MT-G2 lights that run the same FET driver at 11.3A and also have a series light (3s XP-g2’s and 3s cells) that runs the same FET driver at 15A.

You could switch to 4.35v cells but the real world gains would be probably <.5A more. You could also switch to 26650’s or 32650’s but the real world gains would be even less.

So how did you achieve 1/10 mm accuracy? Did you use spacers?

I used pieces of tape as spacers.

My Uf-T20 measured at 170Kcd .

vestureofblood, I did not finish the X7 project, maybe one day :slight_smile: . The collar was custom cut from aluminium at a CNC machine shop.

What about the angle of the collar? How is that done, is it special for the led, or constant but based on the width of the collar or based on the necronomicon and the guy from army of darkness?

“Army of Darkness guy” LOL Bruce Campbell

It’s time to revive this thread again :bigsmile:
I’ve modded mine a while ago with a de-domed xml2, but not on copper.
I just made a couple of tailcap measurements; with a trustfire flames battery I got ~2.2A. Then I tried a keeppower imr 2500, and got 3.5A.
I have some kind of luxmeter on my multimeter, that can use for rough comparisons. With the trustfire I got ~550, but with the keeppower I got ~250.
I had to check if I accidentally had changed to low, but no. Turns out it can’t cope with the heat.
So I’m thinking I’ll have to reflow the dedomed xml2 to one of the copper stars I bought from banggood a while ago and solder the star directly to the pill.
Do I have to order solder paste or can I use regular solder as well for this?

Might as well do the 100th post of this thread myself :-)

If you do yourself a favor, get some solder paste, this stuff is cheap and worked well for many people. I'm surprised that the XM-L2 does not like 3A, it should be alright, also on a common aluminium board. Was the board clamped down to the pill somehow? (screwed, or with a thin layer of thermal adhesive)

Ok, it’s worth waiting for that stuff to arrive from China then…
I used heatsink plaster, some stars-922 probably ordered from ft. It was held in place with alligator clips during the curing time. The current might have been over 3.5, maybe 3.9A even.
It’s the original driver, high/low/strobe, didn’t know the numbers could get that high with spring bypasses.

Although paste is easier he could do it with rosin core solder and 5$ heat gun. Flux it a bit and just heat pill a lot and when solder starts to melt put mcpcb with led(press it) and finished.

Is that method invented by you Djozz? I think you first started with mcpcb to brass soldering.