Cool. I’m more impressed now having seen the video.
Last light is with MT-G2 as you can see from honeycomb beam patern. First one is keychain, second is generic 5 led and third is dedomed XP-G2.
Nice build mtg2 sk98 build!! I like the way you fabricated extra copper for the heatsinking, trust me, this light runs HOT when its zoomed out
For my build, I played cheat and used a bunch of singapore 1 cent coins (made mainly of copper) stacked against the back
Sadly though, it seems to lose a lot of light upon zooming out, probably need larger asperics as the sk98 is still too small, ive moved my mtg2 from the sk98 to a smiling shark sse7 (ultrafire z5 1x 28650 clone), aspheric is now 28mm instead of 20mm
Its a hollow pill, so I filled the entire length of with thermal paste and stacks of 1 cent coins 
It seems to throw slightly better, have you ever considered shaving the mtg2?
Thanks 
I saw your topic, good work. I would only replace/modify switch because stock has relatively high resistance and over the time resistance will increase. My idea of building MT-G2 pocket zoomie was only massive flood so I have no need for shaving or dedoming . To me, zooming is just an option if I need a bit of extra throw. For pocket thrower I have sk98 with dedomed XP-G2 which was before dedomed XM-L2 and in the near future it will be dedomed XP-E2 for max range. About sse7… I saw how xm-l looks under 28mm aspheric. It just looks like it have more throw but that is just illusion because lens has longer focal length (even more light is wasted) thus spot looks smaller. For best light efficiency host had to be reflector based with AR lens (something like convoy S series with SMO lens for truly pocketable lumen monster).
Yeah can’t compare with an XP-G2 or E2… Maybe using special optical lenses? (Ahortons?)
I guess there’s not one light that can do all, I tried putting it into a convoy m2 before, it had great hotspot, but i still prefer the versatility of zoom aspheric hosts… still, even with 20%~ or so loss having 2000+ lumens in a small package still isn’t really a bad thing
I’m becoming a big fan of dedomed XPG2 in small aspherics…. reasonable flood with great throw.
XML2 or MTG2 in aspherics… not as much. You get great flood with the option to goto spot mode for some slight additional throw when needed. It’s a reasonable compromise, but you’d never carry a light like that for throw.
Yeah i agree too… i dedomed a xpe from a random light lying around and put it into an SK98, surprisingly it threw really well, the beam is pencil thin and it flew pretty far, and when un-zoomed it floods reasonably well…
You can always unscrew lens and have 100% light efficency :bigsmile:
I have a domed XPE2 on hand. I’m not using it because the dedomed XPG2s I was playing with have better throw.
I guess I might as well dedome the XPE2 and see how it is. Now that I’ve got the hang of dedoming shouldn’t be hard to do.
can you please put your video on you tube and post a link to it.
so that i can see it. thanks, i can’t see it here
great work…
Both of the vids are posted…wonder why you can’t see em
Here is the first video in the OP
I feel I am missing the explanation of how you are giving it enough current to need the copper heat transfer parts. From the Cree site, 3 A at 6 V. There doesn’t seem to be enough 7135s and maybe not enough batteries for that.
Um…it’s still making ALOT of heat the MT-G2 emitter is what 2x-3X the size of the XM-L and the SK98 just doesn’t have alot of meat to absorb all that heat…copper will pull it away, and then dump it into the aluminum pill, aluminum pill to body, and all it can do at that point is just get hotter and hotter and hotter, these flashlights just don’t have the mass or surface area to convection that heat away…unless you consider the palm of your hand a good heatsink
If you look, he has stacked 18350’s, pushing 8.4v at full charge, thru the regulator (this is why he put the voltage divider 200ohm resistor and zener as to not smoke the ATtiny13)
Per the MT-G2 spec sheet:
The thermal resistance of the MT-G2 LED is 1.5 °C/W, so at 18.5 W the junction temperature (TJ) will be approximately 82 °C
6v at 3A is 18 watts…so he has 179.6F worth of heat in his hand…that is plenty hot to make me want to drop something that hot pretty quick
I am still missing something about how the MT-G2 is driven to its rated current, or why an SK-98 can’t handle less than that.
It is overdriven with total of 12 AMC 7135 rated to 350mA each. Theoretically they should give mi 4.2A on high but I’m reading 4.48-4.52A. 7135s basically don’t ask for voltage as long as emitters Vf is close to input voltage. In this case 8.4v and under load input voltage drops under 7V so 7135s doesn’t need dissipate more than few hundreds miliamps. Copper is added for keeping led performance for longer period…
Ok. Thanks. Somewhere above I missed four of the 7135s.
That explains so much, I am so glad you wrote that concise chunk of data. I can really use it. Thanks.
Nice explanation on the heat issue WarHawk. I need to remember how to do that.
I think many of us here build/mod our lights to have high modes way beyond what the host can handle continuously. I like to have the ability to blast out light if needed. I usually only need high for a second or two. Lows are the best modes for me as I like to see outside of the spill with my remaining night vision. So a light like this is what I strive for. Unfortunately, you can't give/.sell these types of lights to anyone but fellow flashaholics. Well, you shouldn't, that is.
Hahah yeah… gotta love the blast of absurd light some of these tiny modded lights can do.
My modded Sunwayman C20Cs, one with 3 amp MTG2 and the other with Comfychair FET mod and triple XPG2 emit so much light that if you hold the lens against your hand and turn them to max, your skin feels burning hot after just a few seconds. It’s fun… but could be awkward if it turns on accidentally in your pocket.
The MTG2 makes me especially nervous…. 15 minute runtime at max power, no automatic stepdown, can probably set pants on fire from either the beam or how hot the head will get. And to top it off as a 2-cell li-ion light in series it could explode if run too long if one cell depletes faster and then gets reverse charged by the other.
I’d planned to make an alternate driver for the MTG2 using Comfychair’s FET mod + zener diode + DrJones Lumodrv…. but I’m thining I’ll hold off on that. This host might be just a tad too small.
Well it’s a cross between my two hobbies, flashlights and vaping [nothing new really and it’s really basic electronics math]…vaping we deal with watts or heat energy, pulling volts and current thru a teeny wire, flashlights…same critter but we are concerned with pulling volts and current thru a light emitting diode (yeah it generates light rather than heat UNTIL you start pushing it WAY over it’s rated current limits) and we really don’t concern ourselves with watts…till you start pushing em REAALY hard, then you have to take into consideration where all that heat energy is going to go and figuring out the most effective way to move it away from the emitter because heat + LED = very very bad
Simple electronic math…but now we know why when you push a emitter rated for 3A max…why the thing gets more heat out than light, and things get rather warm…fast 
This is also why I really like the STAR V1.1 firmware automatic throttle…you have a 2 min wide open blast out the light/heat turbo [it is configurable as well]…but then it automatically steps back to approx 50% PWM…effectively halving the original heat pumping blast of light, but the beautiful thing about cree is they are MORE efficient at lower power levels…so even cutting the power by 1/2 doesn’t reduce the output of the light we see by half…but it does chop the heat