I have not seen much info on this topic, if any at all.
I would like to see discussion of this , and any photos that people have.
I would like to see this progress beyond using eight 18350 batteries.
M6 is the light I am thinking about. Even at low amps, it would be great, with short bursts of WOW, and a 20 second timer. Any ideas ? Thanks.
Here I am under the impression XHPs are for throw and soda/soup can lights for flood.
It sound like a project do just because it can, though 3 XHPs will generate a lot of heat, I mean one would basically swap 3 for 12 emitters.
Probably because SRK’s lack the heat sinking for even 3V LEDs, only a shelf for the mcpcb.
The most memorable is the Supfire M6 “BMF” edition with triple MT-G2’s. The driver design/series conversion was a bit… questionable… though, and almost turned into a bomb. I have some ideas specifically for the M6 tarver, if you’re interested PM me. The idea isn’t ready for full forum consumption yet.
Basically this OL build, minus the single emitter part. In short I think it’s the same reason we don’t see many new mods with SRK lights period, lack of heatsinking like RBD said.
Yeah, that’d be mine: Mod: My SupFire M6 "BMF" edition (new beamshots in OP).. The conversion itself is not questionable, it’s the possibility to still open the light by the old method with cells still in that’s the problem. I’ve got an idea to use the tripod mount for a locking device, but haven’t gotten around to it yet. I just don’t open it that way, or put the light in the hands of someone with their thumb in the middle of their hand 
I made a new version of the driver and stuck it in a triple XHP70 light. I haven’t done anything to lock out the host opening method on that one either though: Mod: BMF SRK v2 Roche Edition (Rebuilt into triple XHP 35 HI)
With enough room I could make a cell contact PCB to allow screwing on and off. I’m trying this on another light. I’ve got the parts and PCBs, I just haven’t taken the time to put it together yet.
So how thick does the shelf need to be for SRK-type lights to handle big power? How much better, in real light output terms, is a 1/8" thick aluminum plate, versus a 1/2" thick copper plate, assuming both are fitted properly to the head (threads fit OK, and the bottom of the plate has good contact with the step below it)? Am I asking leading questions, the answers to which I think will make the 'SRKs can't handle high output' line sound silly?
This post heavily edited.
Certainly some mass is needed, I don’t know exactly how much.
If more mass is needed to hit the “sweet spot’ for mass, you could even use 3 batteries instead of 4 in the M6, and fill the 4th battery slot with a copper heatsink. Then put a thermo-sensor on a battery slot with thermo-step-down. Unless that’s a bad idea, which seems a distinct possibility.
One could also use a battery slot for a tiny fan, if that would help anything.
The heat sinking isn't the ultimate limiter, it's how quickly the heat can be dumped off the outer surface area of the light into the surrounding air (or your hand, or whatever). Adding a big dumb lump of mass just marginally extends the runtime before the heat path is saturated and doesn't change the outer surface area at all. Once the added-mass light and the non-added light are both saturated, they're identical. You don't want to store the heat anywhere inside, you want to dump it. Mass alone does nothing for that.
I think what was being referred to is that lately most SRK’s you can find only have a thin MCPCB floating on a small ledge, no real shelf at all. Not much to mod with unless you have access to raw materials and a lathe or similar.
I did it before I had a lathe. Cut the threads out of the head ID so it's a smooth bore with a step at the bottom, cut a disc of aluminum to size and press it in, ideally, or JB Weld works too. It does need some careful measuring to make sure the front of the reflector lands in the same spot it was before, but it's not rocket surgery.
The srk I’m accumulating components for will have a heatsink made from a 2” x 1” piece of aluminum round bar and additional external cooling fins from a 3” x 1.5” piece of aluminum round bar with threaded aluminum rod securing the added cooling mass and providing a path from the added internal mass to the added external mass. It may end up looking a bit odd but it should significantly improve heat dissipation.
I’ve put 3x XHP-50 in my SRK. it works, but does get hot fast.
If you want any more pictures or have any questions, please ask.
I did that mod months and months ago for manxbuggy1, it’s a beast for sure! (Think I used 50’s…can’t remember. Might have been 70’s for max output.)
Miller, the XHP series are definitely not throwers, by their very nature. They have that “+” junction between the dies which makes a dark spot in the middle where you expect the hot spot to be. To diffuse this, we use orange peel or faceted reflectors, possibly a TIR. Obviously, this also kills throw.
I see people over and over expecting a die with 4 times the surface area to throw like one that’s 4 times smaller instead, somebody is reversing the ideology. XP-E is tiny, has best throw compared to XM-L with it’s large surface. So, while an XP-G2 might throw fairly well, 4 of them side by side in a square will not. Neither will 4 XM-L2 dies in the same arrangement. (think of focusing a pinpoint of light, easy to send it downrange. Now focus light coming from a square the size of a matchbook, see the issue? Yes, I’m exaggerating but it proves the point.)
The XHP-35 helps with the problem by having the 4 dies virtually pressed against each other, no “+” to contend with between the dies. But being a 12V emitter, it brings it’s own problems to the table…. and still has a much larger surface to contend with as compared to the traditional “thrower” emitter.
Thanks comfychair for being back. In your absence I tried to give some opposition to the tons-of-copper guys in favour of a lightweight but effective heatpath to the shell , but I just can not bring the message the way you do
(this is not directed to you Dale, I know that you love the copper for the copper, the more the better, can’t argue with love )
That said, I think the SRK can be driven pretty hard with just moderate modifications. I have an 9x SRK mod in the planning at 2.5A/led, that is 22.5A total (not sure which emitter yet, XP-L Hi is too expensive), and I think I will get away with the stock ledboard with a 1mm copper plate screwed against it (Arctic silver in between) on the underside. I will use the stock driver with the double FET (see my recent 9x LG 385nm SRK mod) and bypassing the current limiting resistor, shortened 18AWG led wires. Battery spring bypass only if I can’t get the desired current.
Dale you left us hanging !! What driver did you use ? What battery setup ? Did you dedome ?? Any photos or build thread ? Thanks !!
That looks great. Please post some photos! What did you do about heat ?
I have been thinking about this for the past few days. 
M6 triple XHP 50 group buy made by Acebeam ???
That’s the riot I was hoping to incite. !!
Well, it’s been a while. I’ll find it, but have to go eat now.
I know I used a 2S2P cell configuration that MRsDNF made for me. It’s an adapter to use the TK75 carrier in the M6, with a new knurled battery tube. Pretty sure the driver is a Zener modified FET of Wights, but I’ll have to find when it was to get specs as I really don’t remember those details. Think it was making 12-14,000 lumens, something like that. I’ll find it and get back…