Mod: (w Beamshots!) UltraFire T90 (TF X6 Clone), Cree MT-G2 Emitter Swap

My power supply only goes up to about 6.5A, so I tested it at the max available.
Bare SST-90 at 6.5A: 1582 lm
SST-90 with T90 reflector/Lens: 1106 lm
OTF output is 70% of the bare emitter.

Bare MT-G2 at 5.0A: 2810
MT-G2 with T90 reflector/lens: 1900’ish
That puts OTF at 68% of bare emitter.
The losses are basically matching. Not looking good for this reflector/lens…

As a control, I took an XM-L at 3.0A and measured bare and then with a HD2010 reflector/lens:
Bare XM-L U2 at 3.0A: 1036 lm
XM-L U2 with HD2010 reflector/lens: 728lm
Again, OTF is about 70% of bare emitter.
I suspect some of this discrepancy is due to my integrating box not integrating perfectly. Another 8-10% is in the uncoated lenses. The numbers may be close to real. I may need a small ‘box’ factor to adjust for focused sources.
Mule/bare emitter sources appear to be somewhat accurate.
I hope to get more time for this on the weekend; the next day or two will be rather busy for me.

Posting up some info on the Luminus SBT-70:

http://kaidomain.com/product/details.S020860

German Video:

to be honest, the general rule of thumb is OTF lumens = 70-80% of theoretical lumens (bare LED, cooled well), so while 70% is at the lower range, I don’t think it’s completely out of line. I’m also fairly certain that reflector efficiency for a given effective emitter area increases with diameter (I think TIRs stay fairly constant). I don’t really know how big either of the reflectors you used are (not very familiar with torches), but it could be that you’re on the lower end of that efficiency curve.

You’re still getting almost 60% more OTF lumens with the MT-G2 though, which is not to be sniffed at!

I added a small update in the first comment
With my new light meter I measure a more expected OTF output of 2230 lumens. Throw measurement is about the same, since the faulty meter seems to be a problem on the 50k scale only (I measure throw at 3.65m usually).
More to come… contemplating my next move. :wink:

Well you have certainly given this mod a good shakedown. I think it was in one of troutie’s posts that he found that the MTG2 simply doesnt have the surface brightness to be a monster thrower in spite of the plethora of purpose built reflectors he had to play with. Placing 3 XML’s together via direct bond (so the emitters were about touching) produced some rather spectacular results in a large reflector. If you give up on that monster cree, maybe try 3 of the smaller ones all jammed up together. They seem to enjoy each others close company!:smiley:

I’m starting to like the floody nature of it. Plus, the NW tint gives it a real throw advantage; the air doesn’t seem to light up as much.
I may dedome one and see what happens… dunno for sure.

It sounds like youve struck a great useful combination. Range, flood and great tint… all in one. Id guess the SST90 that came stock would probably be low bin. I wonder if a nice new SBT-70 or SBT-90 would be a worthwhile investment? They arent exactly budget emitters though. If it were mine, Id live with the big fat cree for a while and see how that goes.

Nice mod relic38 complete with ongoing experiment. Any thoughts on some beam shots?

Beamshots are planned. At the least, brick wall shots from 40 yards or so. I think I have comparison shots from the SST90 resistor mod.

I’ve added some outdoor beamshots to the first comment, here
I think I’ll keep the MT-G2 in there. I see no need to go back to the SST-90. I have the BTU for reach and the UF-T90 is a searchlight with a giant NW spot.
Because of the tint, it reaches quite far without lighting up the air too much.
Am I done? For now… I may come back to this. I have another MT-G2 mod that I’m itching to start :wink:

Why do I miss so many threads?

I would think (having played with an MT-G2), that it would not be at all suitable for a "thrower", but great for a flood light. I think when you talk about the die size and surface brightness, the texture of the surface also has to be taken into account. It seems like that led was designed for use in flood lights, to cover a wide area. Maybe it would be worth a try with a very large aspheric (in the 100mm range). That might come out better.

Anyhow, it's an interesting test of the led.

This thread has made me strongly rethink my future X7 mods, especially since the SST90 reflector was made to fit that host in andi’s thread. The powerful blanket of light concept has always appealed to me, which is why I have enjoyed the SRK and other similar lights so much.

Thanks for the beam shots. As you mentioned, the MT-G2 really has a very attractive tint and looks like a serious flood powerhouse. Congrats on your great results!

Is Cutter still the only source for these monsters?

Very cool experiment. Thanks for trying a new direction and thanks for the beamshots.

Thanks everyone. The more I use it like this, the more I like it. The tint and big bright hotspot make it a good medium range searchlight.
I haven’t looked recently, but Cutter was the only distributor of the MT-G2 when I bought.

Sorry to resurrect this thread, but I have some Q’s about the emitter swap that could befit others who wish to follow.

1.) Relic, you boosted the light to 9 amps originally, correct? Did you reduce the current when installing the MT, or does the MT’s internal resistance drop the current flow?
-If that isn’t the case, is inadequate thermal dissipation the only thing preventing one from pushing 9 amps through a MT emitter?

2.) Would a MT on a copper Noctigon require any shimming, or shimming of the reflector, to achieve the 2200LM @ 5 amps you report? (78% efficiency tickles me too :slight_smile: )

I put the current back to around 6A with the MT-G2.
I did not shim the MT-G2, but centering the reflector was a pain. I doubt shimming would help with that though.

Thanks Relic. :slight_smile:

Just checked tailcap current…3.25A… :zipper_mouth_face:

The clone uses this driver , even the same printing on the vertical PCB. So time for a resistor mod in the opposite manner as usual then? :smiley: I remember waaay back with the SST-90 it drew about 1.5A.

And I’d forgotten this thread, there’s so many X6 threads here… :frowning: I actually spent an hour making a pair of copper disks, soldering them together, and grinding them flat to space the emitter up against the reflector. I wanted to get the emitter as close to the opening of the reflector because of what you had said elsewhere, about the MT-G2 throwing more light sideways than the SST-90. But you placed the emitter right on the pill with no spacing? So on yours there’s a couple-mm gap between the reflector opening and the emitter?

Old thread but I figure I point out some relevant data for you.

This SST-90 based light appears to use the DX 7.3cm SMO SST-90 reflector which is what the Lamdalights Turbo lights used as well.

I actually use this DX SST-90 SMO reflector in a 80mm 109LED bezel from HF. My 2D MTG2 Maglite is direct drive off 2 IMR 26650 cells and does 5.14A at the tailcap. I get 102K lux with mine. Just epoxy the HF bezel on the 2D Mag and find the focus point and that’s pretty much it.

So, I am generating 43watts plus with my MTG2 and it takes it like a champ on copper heatsink ect…

bigC