Thanks for the info Ledoman! Don’t mean to derail the thread, however I happen to have an old P7 bike light and was wondering if the new MTG2 emitter would fit with a P7 reflector.
There’s a great video tutorial here and a good comparison for beam shots at the end of the video, much brighter and floodier, this will be my next project for sure!
Ah... MTG and MTG2 are completely different animals that happen to share similar names. They require fundamentally different reflector geometries to get similar beam patterns.
I think I'll order a cheap XRE C8 and a separate XML reflector, see which works best. Though I doubt the XML will work (by work I mean a nice usable beam, not work as in the parts physically fit together). What I've seen so far is that reflectors where the walls taper down all the way to the emitter hole with no flat area just do not work with this LED. The XRE reflector will still have some of that flat area left intact even after boring out to 8-9mm.
I think XR-E is as close as you're going to get. Ideally, it needs a custom C8 reflector made for the MT-G2.
O-L you've done a few of these, have you noticed that same thing about reflectors with a flat area around the LED opening?
This one should work as the hole is already 7mm with a flat bottom. You'll only have to open it 1.9mm more.
Yes, what it amounts to is the profile of the reflector. Given a set large OD and the same OAL, if the bottom ID is bigger, then the angle of the reflector is steeper and that seems to work better with the MT-G2. I don’t know enough to be able to say why, but it does seem that it needs a steeper angle to give a better beam.
The X8 clone that 18sixfifty posted about works well with the MT-G2. Beam is ever so slightly ringy when white wall hunting, no where near noticeable outside. I happen to like the result. In a standard C8 reflector it should be OK, but with more flood due to it being more shallow.
All of the C8 reflectors I have would be easy to open up. They all have the flat part at the bottom.
Edit: Just noticed O-L’s post, he has a point, which may make a C8 less than ideal compared to the X8.
This one should have enough flat space at the bottom to open up:
http://www.fasttech.com/products/1617/10001275/1220100-aluminum-smooth-reflector-for-cree-xm-l-xr-e-xr-
Again, you're using the word 'work' as in the parts will physically fit together. I've already been down that route, or about 15 iterations of that route, and found a lot of reflectors that just don't give a nice beam pattern. 7mm is the standard XML hole size.
I was just looking for anybody who'd found a C8 reflector that gave something resembling a usable beam pattern you'd find in a typical usable flashlight, and not something that gave a beam pattern resembling a mule light with no reflector at all (which is about what I got with every variation of P60 reflector I could get my hands on).
Yep, that looks identical to the XRE reflector in my current C8 which I'm not really wanting to chop up, I'll pick up another cheap XRE UF C8 to use as a host and a couple spare pills to go with.
That reflector with a de-domed XML2 looks pretty awful on the wall too, but outdoors it just goes, and goes, and goes... I'm finally happy with it after a lot of trial and error that nearly put me off the whole C8 format altogether.
XML2 in the XRE reflector (with a stupidly ridiculously thick handmade spacer/centering ring, about .065" thick to get the focus nailed down):
I do have a MTG2 in a modified C8 XML host. You're correct. It doesn't have the same type of beam pattern as an XML as the reflector was not designed for that type of LED. It is purely a flooder. However it's so goddam bright I didn't really care. I don't have a beam shot but I would say the hotspot compared to any other light I have is a DRY. As I recall I shaved 3mm off the bottom of the reflector and you'll have to turn the light to medium to see a hotspot white wall hunting. If you are looking for something with more throw and a tighter hotspot, I don't think the C8 (42mm x 31mm) is the right format for what you are looking for. Even a XRE C8 host will not suffice. Why cause I tested it and gave similiar beam pattern.
Don’t forget it might be much hotter. too.
I’m waiting on my stuff to show up but after that I’ll be glad to.
Thanks. Based on OL’s comments just above and the heft of the giveaway light you sent, this looks like it has great potential for a 1x (is there a boost driver?) or 2x MTG2 light.
Relic, did you already post the X8 mod?
I received one of these from Meritline yesterday. The reflector looks promising for MT-G2. Only issue with the light is a very small hollow pill. Fixable, but not ideal. I do like the light though. Running an MT-G2 on two 26650 cells in DD configuration would give decent output. I got it for $14, but a few weeks later it was on for $8.99. I cannot remember the codes, or even who told me about it. 
Edit: Ahh, here’s where I found out about it.
http://www.meritline.com/showproduct.aspx?ProductID=85454&SEName=zoom-cree-t6-5-mode-memory-white-led-flashlight
I modded it for more output and added some thermal compound to the star rim. Surprisingly, it doesn’t perform that bad. Even with that little bit of thermal contact, it still puts out over 750 lumens with a 1.4A tailcap current after a few minutes. It would run like this all day, as the host handles heat quite well. An MT-G2 is going to overheat it eventually, but I may give it a try anyway.
Edit: I believe this light in single-cell form is commonly referred to as a C10.
Ordered...
#1. SKU 1206303 - UltraFire C8 XM-L T6 5-Mode 1000-Lumen Waterproof LED Flashlight x 1 http://www.fasttech.com/product/1206303#2. SKU 1206100 - UltraFire C8 CREE Q5 5-Mode 250-Lumen White LED Flashlight with Strap
x 1
http://www.fasttech.com/product/1206100#3. SKU 1220100 - Aluminum Smooth Reflector for Cree XM-L / XR-E / XR-C Emitters
x 2
http://www.fasttech.com/product/1220100#4. SKU 1203500 - Aluminum Smooth Reflector for Cree XM-L LED Emitters
x 1
http://www.fasttech.com/product/1203500
#5. SKU 1208600 - Driver Pillar w/Emitter Slot for Flashlight DIY
x 4
http://www.fasttech.com/product/1208600
Did you know the only black UF C8 they sell is in a $22 bundle with a 18650 & charger? Weird.
Comfychair, any progress or still waiting for parts. I am looking for a reflector to put on an MTG2 that will throw decently and have some flood. Not the typical flood with some throw as seems par for most MTG2 builds. Does that make sense? At any rate, curious to see your results.
The XR-E reflectors work pretty good, when you take into account how simple the mod is (just enlarge the hole a bit, make a plastic insulator to keep the reflector off the square substrate). But this one gives a nicer beam, not a small hotspot but the spot has a very crisp outer edge and none of the lumpy artifacts in the spot like with nearly every other reflector: http://www.fasttech.com/products/1208505
It's smaller at the front end than a C8 reflector so it needs a fabbed piece (plastic or aluminum) to center the reflector in the bezel. At the bottom, the ring around the base sits on the lip around the brass replacement pills and just by sheer luck gives good focus at that height so no insulator is needed there, if it's centered in the bezel it'll be centered over the LED too.
No reflector in this general overall size is going to do what you could call 'throw', you have to get up over 65-68mm size to do that.
That SST-50 reflector works so well you'd probably come out ahead by starting with the host that it's made for: http://www.cnqualitygoods.com/goods.php?id=1143
2x26650, and can use bigger drivers than the C8.
Thanks, I think… Now I’m trolling the Chinese flashlight sites looking for what kind or host can take a 65 to 68mm reflector. I’ll have to pick up again tomorrow, my eyes are starting to cross.