Host: Ultrafire C12
Emitter: MT-G2 P0 5000K on 20mm Noctigon copper MCPCB
Driver: Qlite 105c modified for higher voltage (zener diode mod) with 4 extra 380mA 7135s, for a total of 12 (4.56 amps estimated)
Cells: 2x Efest 18350 V2 or 2x NCR18650PD (extended)
Optic: SMO with enlarged emitter hole
Tailcap Measurements:
Moonlight: 0.01A (may actually be less)
Low: 0.10A
Medium: 1.25A
High: 4.49A
What can I say? I’ve been doing WAY too much reading on this forum! This build was inspired and facilitated by the great work of many of the great contributors on this forum (special thanks to old-lumens, comfychair, Tom E, DBCstm, ImA4Wheelr, and many others). To think that it was just two months ago that I received my first budget light and began frequenting this forum is astonishing. This is my first completed build, and I felt like sharing some of my experiences here.
Although I have reasonable amount of experience with the finer things in life (mill, lathe, drill press, etc.) and used to have access to them, my current tools and environment are truly “budget”; which fits perfectly into the spirit of this forum. I am currently a law student living in a small apartment with my small family and as such my nice metal workbench has transformed into a study desk, my lathe is now a Harbor Freight rotary tool, and my beefy bench vise has turned into a small suction-cup-mounted device. Juggling family, school, and work doesn’t leave much time for hobbies; such as flashlight building, so my builds are always done at night (when patience has long disappeared) and take a long time to complete. That said, I have enjoyed making these little monsters come to life.
Now on to the build:
This light started life as an XM-L2 C12 with a 3 mode driver which I subsequently swapped for a 105C with a few extra 7135 stacked on it for good measure.
It was pretty bright and I was satisfied with it until I started reading a lot about this…
Reading about comfychair’s C8 mod drove me over the edge… before I knew what happened I was on intl-outdoors ordering one of the big beasts. I also had some reading to do about how to convert the 105c so that it can survive 6+ volts. I figured that the C12 host would be a good candidate because of the large pill and sufficient space (just barely!) to fit 2x18350 cells.
In time, the emitter arrived. Time to get to work!
Hmmm…. it doesn’t fit in the hole (yet!)
I used a rotary tool with a diamond bit to carefully enlarge the emitter hole. It isn’t perfectly round but it is good enough.
Out with the old, in with the new.
Emitter mounted, wires soldered.
Qlite (Nanjg 105c) zener modded, running 12 x 380mA 7135s - thermal grease added to pill threads
Mounted in the pill (with lots of nasty flux residue still on the board!) 4th star chosen for 4-mode (moon-2–25–100%)
It’s alive!
This light has the option of either being run in shorty mode (2x18350) or extended mode for more runtime (2x18650)
Here are the cells: Efest V2 IMR 800mah 18350 and Panasonic NCR18650PD
Copper braided tailcap spring with bronze nub removed to gain extra clearance for the 2x18350s
How does it perform? Very well! To the naked eye, the beam is very similar to my SRK. The hotspot isn’t quite as focused, but it is close. The spill is also a bit wider than the SRK. The beam and tint make this light very nice to use inside the house. The four modes make this light more usable than the SRK for close-up work.
I haven’t done any conclusive runtime tests yet, but on full power the 18350s start to dim noticeably after around ten minutes of use. The body heats up fast on full power, but I left it there for five minutes and although it was almost too hot to touch, nothing melted. It can be run on the second to highest power until the batteries run out without getting uncomfortably hot, which still provides quite a bit of light.
Here are a few poor beamshots (I will try and take some better ones in the next few days)
This wall is not white, but more of a cream color.
SRK, MT-G2 C12 at around 4.5A, XM-L2 T6-3A at around 3.8A
MT-G2 left, SRK right
XinTD XM-L2 left, MT-G2 right
Daylight fixed WB, manual shutter, ISO, and aperture. These shots aren’t very good, I’m going to set up the tripod and take some better ones sometime this week. These are not very good comparison shots because I was handholding everything and in a hurry.
SRK
MT-G2 C12
XM-L2 3A XinTD V4
Again, I have to thank everyone on this forum for all of their contributions which made this build possible.
I will update this post with tailcap readings (only accurate up to ~2 amps with my DMM), runtimes, and better beam shots as time allows.