I posted an update here yesterday and it's now gone, what happened?
Machined the base of the reflector flat (not shown, I also milled out two little pockets for wire clearance):
Switched to different style insulators (http://www.fasttech.com/product/1581402)
Before:
93.5 - stock 'Securitying' SRK clone
117 - stock 6XL2
After:
94 - stock 'Securitying' SRK clone
174 - 6XL2 w/insulator mods
Those numbers are with both lights using Samsung ICR18650-28As charged to 4.20v, on INR 20Rs the Securitying goes from 94 to 120, the 6XL2 from 174 to 215.
I'm getting some really strange numbers here. Testing the driver out of the light, with a single XML2/sinkpad bolted to a big CPU heatsink. 4x ICR18650-28As.
input: 3.83A 3.85V 14.74W
output: 3.95A 3.63V 14.34W
Anybody else find that a little weird?
Shorting the FET gate to BAT+ only gives a minor bump in output, around 150mA. Bypassing D5 & R2 gives the same 150mA bump. So, it looks like it's just a crap FET, chosen to self-limit the current without wasting money on a more complex circuit (jumping LED- to ground it goes way up over 7 amps, so that shows how much it's being limited by the FET).
Standby current is 1.32mA.
I got one in the other day from wallbuys with this same driver. I also jumped the resistors and did a tail cap mod. It bumped it up some but not much.
Any hope for this one at all?
Damn just how many different driver are there for all the SRK out there? probably like 10+ version by now?
kriesler.
It’s like a box of chocolates.
It needs a different FET, that's the only part left that could be limiting it. It's not low because of less-than-100% in the firmware, and there's no other components on there.
The one on the Securitying driver is the best one I have seen - over 8A with a single 20R, too high for me to measure with all 4 cells. K4212: http://www.aliexpress.com/item/Free-shipping-10PCS-2SK4212-K4212-TO-252/1475556941.html
I put one of the security lighting drivers in my SP03 modded up just like yours. Much much nicer. I haven’t tried it with the 20r’s yet almost afraid to. The SP03 comes with a terminator driver stock that is really nice too. I finished up one for another member the other day. Super mod turned out fantastic.
I will probably just end up junking this driver and doing something else with it altogether. I know a good reflector that fits in these for a MT-G2 I’ve been dying to give that a shot. So I might just have to go for it with this one and steal the emitters for another project.
Well I decided I couldn’t stand it the way it was so I swapped the FET out for a DTU nice improvement.
I guess I’ll work some more on it. Probably sinkpads, de-dome get rid of the stupid spacers, heavy gauge wire and some heatsinking and it should be really nice. I’m at just short or 4,000 lumens right now almost twice what it was stock. I won’t even be running it until I do the rest.
wow another SRK clone driver. I have lost count of them all.
Oh, I knew I forgot something - the squeal on low mode comes from the capacitor, C3 (it even makes the godawful noise out of the light and laid out on the bench). Touching the ceramic body with a screwdriver and varying the pressure while it's running makes the noise change.
Please explain the whole process of moding this flashlight. I got the tools to modify my own one but my language skills are lacking a bit. I’d appreciate some photos and a simple description.
Thank you
There is no simple description because it's not a very mod-friendly light. The driver needs major components replaced or a whole new different driver, the reflector needs machine work on the base, and the one-piece LED board is aluminum and not good if you manage to fix the driver and get some serious current flowing.
how many voltage you are loosing in the mosfet? voltage drain-source (vds)
moviles2,
What do you mean with that “repair” spring resistance? I have same kind of driver that you have, and it takes about 7,2A at 4V from power supply. When feeding only leds with power supply, leds will take 3.4V at 7.2A. So that makes (4-3.4)*7.2=4,32W, that is mostly lost to these resistor wich are 0.75W/pc and i have only two in my PCB, am i correct? They heat up so much that you can’t touch those after ~10seconds. Do you have same problem?
What was reason for that you removed coil? And do you also have this thin 24AWG wire to leds? 
The 6x parts in their new home.
Man, this reflector is bad. Has a fairly small center spot (smaller than the 3x versions, which I never would have guessed), but then there's a big dark dead area around it, then a yellow ring, then the outer spill. I've never seen anything like it.