xml2 u2 in ultrafire c8

On the side of the emitter, do you see 2 glob balls of solder? These can keep the centering ring from seating all the way down against the star. Some centering rings are relieved in these areas, as to still seat all the way down, and leave the excess solder balls there. My Noctigon copper star came presoldered with an XM-L2 emitter, and had these excess solder blobs also. This is fine, and is the way the soldering process eliminates excess solder, but unfortunately, the Convoy C8 centering ring is not relieved for these solder blobs, and they needed to be removed in order for my centering ring to sit all the way down.

I used my soldering iron, and a little desoldering wick, to just touch those balls with a hot iron, and a little extra flux on the soldering wick. In a second, they were gone, and I didn’t even need to heat it up enough to dislodge the emitter. Then, my centering ring was able to seat all the way down against the star.

Possibly this is your issue.

Is it possibe to post pictures from an android? All i see is a url option for photos

Sometimes I cut off the dabs of solder that have been squeezed out from the emitter with a knife…carefully. Other times I notch the underside of the centering disc so it will sit down flush over the emitter.

That is correct. You upload your photos to a Server, which provides access to it by means of its “address”, which is called a Uniform Resource Locator, aka “URL”.

The middleware (the “BLF BBS Software”) pulls the picture at that URL and displays it. If you enter a URL which does not reference a picture, the BBS Software ignores it. Please be sure to enter something for the size! “100%” will stretch small photos & shrink large ones to perfectly fit the displays of anyone who views it.

Full details here:
HowTo: Adding pictures to posts
and further reading can be found here:
Search For Post Photo
Thank you for making it happen!

Looks like a very thick led gasket, probably losing quite a bit because of how far down the emitter sits inside of it.

Get rid of that centering disc.

Yeah thats what i need to do but then without it the reflector is still sitting on the wire connections which still raises it just slightly to much and doesnt center. Its as if it ahould be a 20mm star not 16mm

but again it makes absolutely no sense to me cos it worked fine with a xml u2 on a 16mm star :s

Not sure if them pictures worked properly i cant see them my end

How thick is the star the led is on? My Ultrafire c8 pill is just a hair over 2mm deep. I use a 1.2mm star and the isolater disk thing I posted earlier, which is around 1.8mm thick, you can shave it down a bit on the bottom. Anyway I see your star sticking up quite a bit, if you’re using a 2mm star you may want to just apply a very thin thermal adheasive/grease to have under the star. My setup is flush with the pill, and the star under the plastic. Your centering ring is too high, you may need to use a thinner star or grind off some of the reflector and use some isolation tape over your leads.

Yeah it is a 2mm thick star but if it was thinner i still dont see how the reflector can sit flush against it with the solder connections where they are. Is it worth just buying a new pill or just an entire new c8 after all this?

If it was me, I would sand down the bottom of the centering disc you have until it matches the profile of how far the leads stick up, then isolate your leads with some tape. This should allow you to drop 1mm or more down and still keep your centering disc, raise led into reflector and not short your leads.

This just doesn’t make a sense to me, centering ring didn’t just become thicker overnight, it has to be something else…

I think the xml he had on first had a thinner star. He’s got a 2mm star now.

That shouldn’t matter in this case. The emitter would still be the same distance from the reflector because of the insulation gasket/centering ring

Good point.

Edit: unknown was faster 8)
That wouldn’t make a noticeable difference, gap between the top side of the star where emitter is soldered and reflector is unchanged and it is defined by centering ring so the position of reflector in relationship to emitter is unchanged. Only thing that thicker star could do is that bezel would not screw down as much (for added star thickness which would be about 0.4mm).
Something else caught my attention: it is the condition of reflector, my guess would be that
before flashlight failure, reflector was fairly clean as most of them are from factory but in the
“repair” process H1ST failed to pay attention to this important detail and reflector now looks
like this :

so, plenty of fingerprints and scratches, I would comment this as pretty bad condition.
I am not sure if this would make a noticeable difference but it sure sounds as a better theory
than “star thickness”…

Well I read back through most of the thread…

Could you please post a picture of the XML that was in it, the xml2 without the centering ring on it, and the underside of that centering ring?

Trying to rule out anything simple that may have been overlooked.

Edit: I noticed the reflector damage too. I’m not sure how much of a difference it would make, but it definitely looks like it was wiped down a bit. (Reflector coating is extremely sensitive and will scratch if you look at it for too long).