A closer examination earlier revealed that the reflector was not properly seated over the LEDs. I placed layers of kapton tape over the copper stars to ensure that the reflector wonāt short with the lead wires. The result is that my centering rings cannot be fitted properly over the LEDs because the tape was too thick. I removed the excess tape leaving a single layer over the lead wires allowing the centering rings to fit properly and the reflector to be properly seated over the LEDs.
Upon testing its beam, the dark spots were already gone. The misalignment and improper seating was the culprit of my ugly beam earlier.
I also took its lux readings at 6 meters and the average is 6265 lux which is equivalent to 225 KCD. A 17% increase over the improperly seated/aligned reflector and a 69% increase over the stock light. :bigsmile:
Sorry I donāt understand something here, you got 225kcd after dedoming the LEDs, the lux numbers seems a bit low for a dedomed XM-L2 BTU Shockerā¦
Tom E got around 180kcd by just simply swapped the LEDs into XM-L2 on Sinkpad with stock BTU driver. Or is it you did not mount your LEDs on Sinkpad/Noctigon?
Well thatās what I got after swapping my stock XM-L LEDS with dedomed XM-L2 T6 1Bs on ordinary copper MCPCBs. I did not use Noctigon or Sinkpads, just ordinary copper MCPCB. I ordered my XM-L2 T6 1Bs from Simon Mao and my copper MCPCBs from LED-DNA.
The lux readings of my stock Shocker (XM-L) was only 2690 at 6 meters or 133 KCD. It increased to 3870 lux at 6 meters or 192 KCD when I swapped dedomed 3 XM-L2 T6 1Bs on copper MCPCBs in it. It further increased to 4540 lux at 6 meters or 225 KCD after realigning and re-seating the reflector properly over the LEDs.
Yes - there's a couple of major differences there - T6 vs U2, direct thermal path copper boards vs copper boards with dielectirc layers. Other issues may be the way we measure for throw - I always hunt for the highest reading whcih is usually not the dead center. Most do this because that's what the standard says or implies - peak beam intensity.
Actually I followed your tip of looking for the highest lux readings within the hotspot and in my tests so far its usually between the center and the edge, not the center, of the hotspot.
Therefore I can still improve the performance of my BTU without changing drivers by simply installing better XM-L2s and direct thermal copper boards?
Anyway, I am already contented with its performance, for now, because it has surpassed my modified K40 already. The K40 uses the same dedomed XM-L2 T6 1B LED. I ordered a handful of these LEDs from Simon. My priority for now is getting this K40 to perform like (or at least closer to) the ones you & vinh worked on. :bigsmile:
Took the lux readings of my BTU in my office (yes my office) at 11 meters distance (I can only get to 6 meters at home) a while ago and Iām getting 3381 (average of 5 measurements) lux or 409 KCD at 1 meter.
I guess the readings I took at home at 6 meters is not accurate since it only gets me 225 KCD! The BTU modding I did wasnāt bad after all.
Yes I did them all with the patient coaching of the experts here like TomE.
I used XM-L2 T6 1B LEDs from Simon Mao on my BTU Shocker, Sup Beam K40 and Small Sun ZY-T08. I dedomed all LEDs by āmarinatingā them in gasoline. All three flashlights give the same tint which is greenish neutral white.
For the K40, I did a direct-wire like TomE did, i.e. a jumper wire was connected over the sense resistors and all lead wires were replaced with AWG 22 from IOS. Iām getting 3.77 Amps at 11.67 volts at the tailcap but I only get 2.55 Amps at the LED. I think something is wrong with my K40 driver. The mod only gets me to 252 KCD as opposed to 400+ KCD for TomE who did the same mods.
For the BTU Shocker, I reflowed the XM-L2 LEDs on copper MCPCBs (not Noctigon or Sinkpad), made a mirror finish on my pill using 1000 grit sandpaper, and replaced all lead wires with AWG 22. This mod gets me to 409 KCD.
For the T-08, I also did a direct-wire and replaced all wires with AWG 22. I also replaced its lens with AR lens from CNQG which is a millimeter thinner than the stock lens. To cover up for that and since I donāt have a 25 mm copper MCPCB, I used the stock 25 mm aluminum MCPCB but added a 1 mm copper heat sink behind it and a 2mm copper heatsink inside the pill. This mod gets me to 208 KCD. It can still be increased because Iām only getting 2.41 Amps at the tail at 4.16 volts for the direct-wire. Iāve read others using Nanjg drivers and getting currents as high as 4.5 Amps. I used a V10+ 4 Amps driver before and I loved the ramping but I can only go to 2.01 Amps at 4.12 volts at the tail thatās why I switched back to its original driver.
I'm working on 3 right now - with one I'm concentrating on, I'm having focusing issues with the dark areas in the center of the beams - throw # is in the high 300's, not 400's. Need to do more tweaking -- this takes a lot of time. I don't think I'll be doing any more than I already committed to - too much time and effort.
I'm thinking using 20 gauge wires is hurting - should have used 22 or 24 to lower the profile of the wires over the PCMCB's -- the wires is what the reflector sits on when tightened up. I'm gonna try sanding down the back of the reflector and maybe sanding down the 3 plastic LED alignment pieces to maybe cut down on blockage of light beams.
What I did with my lead wires that posed a problem in āseatingā the reflector was remove the thick silicon skin, flatten the wires a bit, then enclose them with kapton tape. I did not wrap the tape around, I just merely folded it over the āflattenedā wire.
hhmm!! Good idea!! Believe it or not, I stopped at Harbor Freight last night on my way home from work and bought this: http://www.harborfreight.com/4-inch-x-36-inch-belt-6-inch-disc-sander-97181.html. Plan on taking down the back of the reflector a little to see if that helps. Also, want to sand down, a little, the plastic LED alignmnet pieces - thinking they partially block some output as well - done it before on other lights and it helped.
But -- gotta look at what you did first. What gauge wire did you use? I used 20 gauge on the long wires to the driver, and 22 gauge for the 2 star to star wires. What I did different this time was angle the wires to overlap the star more because last time, I had a partial ground on an exposed wire to the reflector. So for this time, I got more wire insulation on the top of the star but less risk of grounding -- can't win...
I should have used the 22 gauge for the driver as well - don't think the 20 gauge makes any difference -- should have had detailed notes on all these mods... argh! Also got a Shocker in from JOE that vinh mod'ed - it's got a worse out of focus condition than mine right now so I'll need to re-do that one as well.
Oh --- comparing these side by side, the vinh one is supposedly U2 1C's de-domed and mine is IOS U2 1A's de-domed and what a tint difference!! The 1C's came out pretty dark yellow. Still wonder if they were actually T6 3C's -- so much yellow when de-domed...