18350?
Did you remove the signal spring? What driver are you using?
Yes, you can see a piece of copper that carries the signal. I guess this is what enables 18350 support.
The picture is a link 
Sorry, didnāt notice if the pic is link.
Thanks CRX & Agro 
There have been a few threads pop up lately regarding collars and RLT. Since Iāve been locked down in the house I thought Iād experiment a little with a UF-1504. So, this whole project probably took no longer than 20 minutes. Sanded both ends of a Maglight AA Mini reflector as it was the smallest reflector I was willing to destroy. Obviously not spherical, but it looked pretty close. I didnāt bother smoothing out the sandmarks as you can see. Put a coat of flat black paint on the outside.
I did no tuning or calibrating or anything like that. Just sanded it and guessed it looked about right. Light has a dedomed XPG. Took readings at 10 meters with an HS1010.
Without collar: 308 kcd
With collar: 384 kcd
I swear this light used to put out about 400 kcd when I built it 5 or so years ago. I probably havenāt touched it in as long. I was thinking of replacing the led sometime in the near future. Anyway, Iād say score with the Maglight Mini reflector. Once you Dremel off the outer edge it fits nicely in the 1504 pill.
Nice. 
Nice mod Willy
any artifact rings around the hot spot?
Nice bump! Maybe elevating it a bit will get better results, but still a cheap bump.
Thanks. Itās not ringy at all after I painted everything black. There is one very faint large outer ring, but Iām not sure it itās possible to eliminate it. I did notice the led seems more defined on a wall shot with the collar. I can even see the outline of the square pad.
I will try moving the collar up a bit and taking more readings. This light is reading very low for some reason. Maybe because it has sat for so long. I think Iāll try sanding the solder blobs on the ends of the springs first.
Cleaning the lens and all electrical contact points could really make a difference. Once you have it all tuned-up Iād love to see you repeat your w w/o collar readings. What cell and driver are you using?
I got a SBT90.2 in a 1504 pill - it does 500+ kcd. Would be interesting to try a DIY collar on it...
Niteye Eye10 Rotary
219b 3000k 9050 D200 (trailhunter LED),
Upgraded mcpcb, reflector and centering ring (moderator007 finds),
Driver has Strobe at double twist,
Sapphire lens (Archibald Tuttle tip)
Remove detente ball and spring, relube with Nyogel 767a high damping grease, and install glow marker (tx pinkpanda) on tail.
Whats not to Love?
Whatās up with this reflector showing 4 bright spots?
It seems that quad effect is related to having the camera closer to the LED than the focal distance of the reflector.
Notice that reflector in the Eye10 is not all lit up, because I am holding my iPhone really close, hoping to show that the LED centering, turned out Really Well!
I checked and the same short focal distance quad effect happens with other lightsā¦ once I pull back to fill the reflector with the light of the LED, the effect disappears
this is a reflector from a Maratac CR123
up close:
farther away:
this is a reflector from a V10a
up close:
pulled back:
Yeah, but I would expect it to show more or less a ring. I guess large die size (and therefore more pronounced squareness) relative to ref size plays a role hereā¦
BLF GT White Flat 1 WHY! PITA 
(Got bored, waiting on parts for a 90.2 build)
2S2P to 4P Carrier modā¦ simplicity at its finestā¦
Mtn. SRK/M6 Linear Driverā¦ 5.2amps Big Springā¦.Simple 3 modeā¦
Hmmm so far so goodā¦ 725lmā¦.680lms until batteries are DEAD!
Let the games BEGIN! 
Nice work KB!
Any throw numbers?
Iām curious to know numbers too. Great mod btw Kawiboy
here is an example of the beam from the stock reflector, that I removed
and an example of the beam from the upgraded reflector, that you noticed has the quad effect
this reflector has a smaller hole at the bottom, both LED are 219b
He just wanna make us beg... K, i'm begging... 