Teardown and Mod Thread of Courui XML2 Aka "Big Head 3x18650 Side-Switch Thrower"

Interesting, I don’t have any way of testing that myself so if you do some detailed testing that would be good.

Mine is definitely quite warm compared to all my other cool whites so I’d expect to see a slightly lower overall output compared to the bluer 1As and greenish 1Cs.
Love the tint though and it’s plenty bright for me, 1As for me are only really an option for dedoming.

Ouchy, Tom is talking about the led I used to replace the stock one. The stock led is most likely a T6 and the one in mine looked like a 1B/1C tint. Replacing it with a known u2 emitter on copper is a must if you’re aiming for 7A.

Yes, I got I think like 3 1D's installed now, and definitely a slight rosy tint in the spill, compared to a 1A or 1C, but I do like it - agree with your impressions of the tint. I bought 10 1D's bare at a good price ($4 each) from Hank a while back, and got lots of bare SinkPAD's and Noctigons.

The rattling does not seem to fully stop when the LED shelf is overturned. So what I have done is used around 4 layers of kapton tape on the underside of the reflector. Add to that, the slightly thicker Noctigon plus the wires, it should stop the rattling. I did a test fit, sans the wire, plus half turned the shelf so that it wasn’t fully tightened, and this did result in the head to stop rattling. I am hoping the half turn would be equivalent to the 18G wire I will be using to wire it up.

Focusing the emitter is something I have not been able to do just yet. However, I will be positioning the LED as far into the reflector as much as possible.

Have you seen my build thread on this light? The underside of the shelf was also badly scratched up. About 30 minutes worth of lapping fixed it right up.

Before:

After:

[quote=Rod911]

Cool, yeah those scratches were really deep on mine, in the middle the gouges where about a millimeter deep and I didn’t feel like removing that much material from an already very thin shelf. I guess it all depends on how heavy handed the dremeling is on each individual shelf.

I may still lap it smooth when I get round to upgrading the heatsinking since then it won’t matter that the shelf is a little thinner, probably wouldn’t matter now either but hey… :stuck_out_tongue:

Oh but adding extra layers of kapton tape to the underside of the reflector seems counter productive to me. Since that will hamper how low you can sink the reflector over the emitter for focusing. If you can’t bottom out the shelf even when it’s upside down then I’d say it’s not worth sacrificing your ability to focus the emitter.

The stock centering ring is WAY too tall, so I’d take that down first to the point where when everything is tightened up you have the emitter in perfect focus, then see how much you need to shim the emitter shelf to get some pressure on those threads. Do you have some copper pieces/plate you could use to make shims between the bottom of the emitter shelf and the body?
I coiled some copper wire to act as a spacer but that’s obviously not a good solution, just lets me tighten the shelf threads up.

I just drilled a big hole right through the middle. That took care of the scratches.

If the heat still has to go through the stock threads it really won't matter much what the plate's made of or what's added to it.

Don’t worry. I’ll be posting my rebuilt pill. That little copper nugget is just the tip of the iceberg.

Hmm, I decide to come back on and the first post I read has this ‘Modder’s Dream’ in it… nice. I guess I need to polish off my international credit card :wink:
Anyone measure the throw with a dedomed XML-2 U2 1C in there? That reflector really looks like it should throw, and the beam shots show it as well.

i ordered mine from kaidomain and it’s taking for ever to arrive, its been close to 4 weeks and still waiting

I meanwhile got mine, too, and just did a driver mod like LinusHofmann in #98 (desoldered all components from the board to simply use it as contact board, and get in a NANJG105C 3.0A with custom firmware) and of course used better wires. I'm quite happy with it. My Skilhunt K30GT (firmware modded) blasts it away though :)

Hehe not surprised there! :slight_smile:
Out of interest did you also shorten the centering ring to focus up the emitter better? It’s really far off optimal on these when stock.
I’d be really interested in seeing some beamshot comparison photos between these two lights if you get a chance.

No, I found the beam ok as it was.

Oh that’s interesting maybe the tall centering rings aren’t a problem across the board. If you get the light apart again I’d be interested in a measurement of the emitter centering ring to see if it’s a shorter one. Wouldn’t surprise me to have some variation on these parts.

Was anyone ever able to get a decent increase through resistor modding the stock driver?

I Added an R100 resister and got 4.1A. I could smell some burning at first and saw some smoke curling out the top of the pill. I don’t know if it was just old flux burning off, but I used it for a few days like that with no problems. I intended to use the stock driver as a contact board anyway, so I waited to see what would happen.
Nothing else happened, but the board has since been stripped of components. You could try running it for a while outside the light and see for yourself.

If I bypass all the sense resistors will I get direct drive then?

How do I do a tail-cap reading on this light? I don’t know where to place the leads.

Remove the dinky little wire, place the leads on the solder pads where the wire used to be.