Cree MC-E Turbo Tower, GD1000 driver, KT1 TH, FM 3xC body

darkzero

Flashaholic* ,
Joined
Oct 7, 2003
Messages
4,459
Location
SoCal
Never would have thought a MC-E would have fit through the reflector without boring the reflector. Thank you for sharing. :thumbsup:
 

LED Zeppelin

Flashlight Enthusiast
Joined
Sep 14, 2005
Messages
1,876
Location
Great Lakes
A literal square peg in a round hole.

I had just assumed an MC-E would not work on a tower module, thanks for proving me wrong.
 

koala

Flashlight Enthusiast
Joined
Mar 5, 2003
Messages
2,295
Location
Melbourne, Australia
One of my KT head has a smaller hole, the corner legs have to be filed down so short making it hard for connection. But yeah it's a tight fit for all KT heads but it's worth it, the beam is beautiful.
 

TigerhawkT3

Flashlight Enthusiast
Joined
Jul 2, 2006
Messages
3,819
Location
CA, 94087
If you're only driving it at 1A, and in 4P at that, what's the point of using the MC-E? A bit more efficiency over a single-die emitter?
 

TigerhawkT3

Flashlight Enthusiast
Joined
Jul 2, 2006
Messages
3,819
Location
CA, 94087
Did you look at the beam shots? IMO, the MC-E at 250mA per core (4P at 1000mA) holds its own against an MC-E at 500mA per core (2S2P at 1000mA). If you want throw from an SF TH, then you wouldn't use an MC-E at all. You'd use a single die emitter. If you want a nice combination of throw and spill, then an underdriven MC-E works just fine. Sure I can see a difference vs the 2S2P MC-E in white wall comparison. Do you see much difference in the hallway beam shot? I don't. Outdoors, even my SOB1227-driven 2S2P MC-E (613mA per core) tower might outthrow this underdriven tower by only 15%, except now I'm burning well over 8W of power vs about 3W for the underdriven LED. If I want throw, I'd go with my SSC P4 Mag mod with smooth reflector.

This build was all about low voltage, low power consumption, low heat, long run time, and flexibility to use C NiMH, AA Eneloops (using C shell adapters), or C alkalines. In fact, I probably can get reasonable performance using AA alkalines in C shell adapters if I'm scrounging for batteries. I could even use 2xC plus a spacer and probably run in regulation in boost mode since Vf~2.95V. I didn't have the goal to build a thrower or a mega-lumens monster, and this light isn't one. SSC P4 towers have better throw since they focus better for a given reflector. I've built plenty of 2S2P MC-E towers driving the LED at up to ~600mA per core. This 4P MC-E build holds its own. I'd estimate about 20% greater lumens output vs an SSC P4 U2xxxH-bin driven at 1000mA, while using about 10% less power than the P4. If I wanted to drive the 4P MC-E harder, I could have used a GD1500 to run the LED at 375mA per core (or even built a GD2800 sandwich for 700mA per core). But then the MC-E would be burning about 4.8W (and about 10W for the sandwich) instead of ~3W, which is contrary to my goals for this build. The light draws 0.865A at the tailcap. With about 5Ah capacity for the Accupower NiMH C cells I'm using, that gives me a run time of almost 6 hours. I measured a hot spot of 5000 lux at 1 meter and a midpoint spill of 140 lux at 1 meter. The hot spot is brighter than my Malkoff M30 and my old Gladius, so the underdriven MC-E is no slouch. The spill is huge and also very bright. It puts the so-called SureFire L4 "wall of light" to shame (of course, this lego is also much bigger than the L4).

I don't care about max lumens bragging rights, and I don't waste my time on impractical builds. I'm interested in reliability and functionality.
That sounds like you were after efficiency, as I thought - and this light accomplishes that quite well. :) Nice work!
 

Kestrel

Flashaholic
Joined
Oct 31, 2007
Messages
7,373
Location
Willamette Valley, OR
Good stuff, I dig the focus on efficiency. How do you think this would compare to a direct-driven Malkoff P7 drop-in in this host, instead of the LED tower + (defocused) turbohead? I'm guessing that the P7 would get initially higher outputs, but with a considerably floodier beam and less runtime?

(BTW what are your plans for that FM 2xC body you recently picked up? It would be cool to update this thread with a side-by-side comparison like I did to compare my two FM C-cell bodies using similiar configurations. Note to others, my sigline has a thread of my related build using the FM bodies and a somewhat different LED tower built by Justin Case - another example of a very efficient build.)
 
Last edited:

Justin Case

Flashlight Enthusiast
Joined
Mar 19, 2008
Messages
3,797
Good stuff, I dig the focus on efficiency. How do you think this would compare to a direct-driven Malkoff P7 drop-in in this host, instead of the LED tower + (defocused) turbohead? I'm guessing that the P7 would get initially higher outputs, but with a considerably floodier beam and less runtime?

(BTW what are your plans for that FM 2xC body you recently picked up? It would be cool to update this thread with a side-by-side comparison like I did to compare my two FM C-cell bodies using similiar configurations.

Post deleted.
 
Last edited:

Kestrel

Flashaholic
Joined
Oct 31, 2007
Messages
7,373
Location
Willamette Valley, OR
I really didn't want to spend more money on another KT1/KT2 TH, but will probably have to. I was trying to think of a similar, low-power solution that could use a standard 6P drop-in. I might mod a drop-in to use a 4P MC-E and driven by a 3xAMC7135 board.
The thing that I see is that if your goal isn't a high degree of throw, those FM bodies are equally at home using 6P-type drop-ins in a standard SF bezel, so it would be cool to mod a compact drop-in rather than building an LED tower to go into a 2.5" $F TH that wouldn't throw like all-get-out.
 

maxspeeds

Flashlight Enthusiast
Joined
Jan 24, 2007
Messages
2,177
Location
Oahu, Hawaii
Great data, Justin! It really shows how much the KT1/KT2 aids in heatsink compared to the shock resistant KT4.

I'm surprised how cool the 4P MC-E ran at 250mA per core
 
Top