Have you tried focusing the xp-g2 to improve the throw?
No - I wasn't getting much power from it anyway - didn't think it was worth it. From a close range of 5-6 feet or so, the beam looked well focused, but further out, it developed a significant corona in the pattern, so I think it could have used focusing. Still, it's one of the highest kcd #'s I've measured, only beaten by a couple of Shocker mods, best being the one I built for the BLF competition last year.
I need to spend more time on hot dedoming, and go thru my batch of XP-G2's - I got one performing well at about 5A from gas dedoming.
maybe you had just bad luck with faulty emitters- both the xm-l2 U4 1A and xp-g2. Cant wait to see the next results, I believe this light has more potential than it has already shown.
I totally agree. So, figured I'd try a XPL I have here, bought from FT - a claimed XP-L V6 0D (bought 3). I hot de-domed one, came out clean, bench tested to reach 5A so I'm happy it's got full power.
First tested on one EFEST 26650 cell and got 5.15A tail (@switch), 575 kcd measured at 5m.
Then taking some risk, put in the 4 cells and got a 5.95A tail reading at the switch, and got 635 kcd (taken at 5m), 1594 meters
I'm a lot more impressed now, also knowing most likely if I took the reading at 10+ meters, it could go as high as 10% more, meaning as high as 700 kcd, and this is without an AR lens, and did no tweaking for focus, though it looks very impressive.
This is the highest throw reading I've ever taken on my meter.
Outdoors against the 280 kcd Convoy L2, it's a noticeable bump up.
It is a beast. Waiting for Chris at flashlightlens.com to get back to me. Might just go ahead and order a 88.5 or 94 mm that he stocks - the 94 could be trimmed/sanded down, or the 88.5 would probably fit ok.
At this point, I'd have no problem recommending this light for it's sheer throw potential. There are issues, like the threads which I have some concerns about, but you just have to be careful with changing cells.
Tom do you have a modded Courui? Do you think I’ll be able to see a visible difference between ~400kcd and ~650kcd? Or will the difference really only be found with measuring equipment?
Impressive numbers! Could you try measuring the throw without the lens? To see how much it lowers the output. Such readings would be closer to those with an actual AR lens
400 kcd vs 6xx kcd? Boy, no clue - more light on a target even at 100 yds, so you can do the calculations exactly how much light is thrown at what distance. The range is based on 1/4 lux (moonlight level).
I would need some range to compare and can't do that at my house. I got a modded COURUI but slightly modded, not much for throw. I got a modded K40 though, dedomed, does high 300's I think. Also got a TN31 but it's been down for a while - not sure if it works.
I'm not sure how to do the test without a lens reliably -- have to think bout that - might need some sort of spacer to keep the reflector tight. I usually get 5-6% bump on pure lumens, double that for kcd. The glass lens looks like nothing special.
400 will sorta show that there’s trees across the Mississippi River. 650 will show you what shirt a guy is wearing on the other side of that great River.
This was shot with my TK-61 right after I got it and with my first mod attempt. I couldn’t get it completely done before we went on this trip, so it was only about 430Kcd, or in that neighborhood. The range to the trees across the river is 1158 yds.
While you can sorta make out the trees, at 650Kcd you’d be able to see a man standing there fairly clearly. I don’t have such a shot from a light I later got up to 665Kcd, regretably.
Some pics of the holes drilled/tapped to secure down the LED shelf. I used brass flat head screws, what I had that fits. On that ledge the screw holes are in, I used a light covering of thermal grease in the final assembly.
This is a view of the driver (20mm) I'm planning on using, and where I'd place it. On this area of the board, I could connect up 3-4 batt- pads and wire them to the new driver's top edge, which is nice and wide. I think it's a pretty good setup for the batt- signal. For the LED+, I'd use the existing 20 AWG wire, then wire batt+ separately to the driver to power the MCU - I typically use 26 AWG wire because you don't need anything heavy for that.
Notice above the longer jumper just above the OSHPark board - I added that from the what I did originally. On the left end of that jumper, I scraped off the silk screening to expose the copper trace, so I could solder to it. Figure any improvement over traces has to be a good thing. Was thinking of doing these jumpers on the traces on the opposite side (batt+ side), but I think they would interfere with the cells when tightening the battery tube on.
Ugly, non professional look, yet functional and stable 
(I am using normal one face cladded PCB ground away the copper I don’t need by air tools and soldered whatever necessary to close the circuit. There is a locating Alu-bronze pin to brass tube which is embedded 20mm into the body (with a spring around the tube to hold the pin)
With XHP70 N4 1C on copper MCPCB from KD, powered by 18x 7135 HZ-3902 driver, modified 2s2p 26650, what I get:
4000+ lumens (~ 3800 lumens after 20 seconds), just approx. 15% lower than K60 by comparison.
~160+ kcd (centre point “flower shape” shows similar lux compared to TK61), throw better than K60 even the lens is un coated and chipped off at one edge.
During modification, one of my XHP70 was “dedomed” (fail) by tightening the reflector base onto the LED :_(
The XHP70 base plate surface has to be at least 2mm below the reflector flat base in order to avoid round dark center, as discussed here
However this will reduce the lumens by approx. 15%.
The PCB is held by the 2.4mm Alu-Bronze pin (welding rod) and spring which is wrap around a brass tube embedded into the battery cartridge. The negative short springs are from intl-outdoors.
XHP70 is 2+mm below the reflector surface
Compared to TK61 on the left
Nice work! If you wire bypass those springs you’ll get even more. Stack some chips or go with an FET driver. With the equivalent of 4 XM-L2 dies on board, at only 1.7A available for each one (here we go again, probably figuring this wrong) there is room for more.
My SR-90 is running a High CRI XHP-70 from a Zener modified FET at some 5600 lumens. The normal XHP-70 was doing over 6300 before I pulled it in favor of tint. Sheer power helps to close up the donut hole if you don’t have a reflector like the Lum 5-90, which my Intimidator does.
Edit: Very creative with that pcb manipulation, I’d have never thought of that! Does the large driver board have a Zener mod for the MCU? Is it built in or just modified? Looks like a very viable option. Thanks for sharing… nice fat spot light for search and rescue type work, should have pretty decent runtime with the right cells loaded up. Sweet!
Thanks. Great suggestions. I believe the amp I got is < 6A although is 18x 7135 (=6300 mA) due to high resistance.
Before increasing to higher Amp, the next thing I need to add is a better Heatsink. The brightness decrease rapidly after switching on the power, I believe is due to temperature increment. The original Alu pill is not sinking the heat fast enough.
Makes me wonder if the Illuminations Machines Lum 5-90 would fit in there and maybe give some space to raise the shelf, use copper and replace the shelf completely with a thicker copper version. Might be worth looking into. While those are only about $5 each, they make you buy like 5 at a time. A group buy here would easily manage the purchase requirements.
Also, the Lum 5-90 isn’t as robust as that original reflector, it can be trimmed with scissors pretty easily. 
If he’s getting 6amps at the tail, it would be 3amps to each 3v die. Very rough example: 6amps at 6v = 36watts = 12amps at 3v split between 4 dies = 3amps each.
I thought about this briefly, but the Boss reflector is pretty shallow. I think you would actually have to extend the bezel somehow for it to fit. (which is a bummer)
Sorry for the interjection here folks, gotta wrap my feeble mind around this while the opportunity is present… I know the XHP-70 has 2S2P on the 4 dies, and is 6V in that configuration. So with 6A, each pair is getting 3A at 6V. Since it’s the voltage getting split, the amperage remains the same? Is that it? Like an inverse of doubling cells in series keeps capacity at single cell level and doubles voltage, parallel cells doubles capacity and keeps voltage at single cell, so because the paired 3V emitters are splitting the 6V power supply, the amperge remains the same at 3A, ok, I can see that. Hope I can remember it. (you noticed my statement was flagging my memory, even if I couldn’t remember why, lol)
Ok then, we know the XM-L2 or XP-L die can take 5A+, so there’s headroom either way. Some 4A to be had there, Go for it! hahaha
(yes, I have destroyed plenty of expensive emitters in my time. How about slipping and crashing the bond wires on a bare Luminous SBT-70? I like to remove the window, the AR coating gets in the way, yeah, that was a cursing, cringe producing moment to be sure.)
Yup
Okay, let me make sure I’ve got this straight…
If I buy my wife 2 boxes of chocolates, her smile lasts a limited time but her capacity of enjoyment increases. If I buy her chocolates AND a bouquet of flowers, her capacity of enjoyment remains the same but her smile lasts longer. Right?
Oh, and mentioning her increased capacity shortens my life span, like an abused high discharge cell.
A UCLp lens is officially listed for this light now, here: https://www.flashlightlens.com/index.php?app=ccp0&ns=display&ref=apps_specs 
, and I got the first on the way 
.
Nice work Tom! So do I put the horse… order the lens… before the cart… before the light? I DO have several other sizes I’ve been intending to order….
We need to know where this stands with freeme. I haven't talked/pm'ed to him at all on this. He's got a decent # signed up, not great #'s, but didn't expect that - pretty specialized. CWK looks like he did a nice job for an XHP70, could have been pushed higher though, and I set mine up more for max throwing, but I'm still nowhere near where I want it to be. Both though show the potential.
What CWK did though could also work with a buck driver, driving a XP-G2 at high amps. If a copper heat sink could be machined to fit in place with the aluminum shelf, or replace the shelf, it would be pretty awesome.
What I'm wait'n on is:
- parts to come in to build up a driver
- hot dedome XP-G2 S2 2B's I have and cherry pick the best performer for amps. Clamp meter would come in handy for this.
- 90mm UCLp to arrive, it's shipped