For me i just wrap a folded and very compressed alu foil, and then wrap the drop-in. You will feel quite a bit of resistance when putting the bezel + drop-in in.
Effect is that the aluminum host gets very nearly as hot as the bezel. That means you are doing things right.
Ok, 20 mins run results : All figures are directly comparable because they are ceiling bounce at the exact same spot. Cells voltage are the same, flashlights are fully current regulated.
Temperature : 30.8 deg C, 15 kph wind blowing at the flashlights.
Trustfire TF-3T6 (4.1% drop after 20 mins)
40 seconds - 57.7
2 mins - 56.9
13 mins - 55.5
20 min - 55.4
Uniquefire 3900 : (6.7% drop after 20 mins)
40s - 61.8
2 mins - 60.4
13 min - 58.0
20 min - 57.9
HI 2100
Was that test done with out foil added to the 3900 ?
Benckie, that’s done with foil added, though i just took like 3-4 minutes to fold and stuff it in, so not too good a job there but i guess it works. It’s somewhat tight though so i guess not too bad overall.
It was pretty warm last night (literally no wind!) so heat was like stuck in the room. 15 kph probably is equivalent to maybe 10-15 deg C without wind?
The fry rays are definitely warmer from my memory.
Thanks mate I was just wondering still unsure what 3 x Xm-l to get my old man I'm going to go with the good old faithful TR-3T6 I think
If you want something that still has reports with failures during operation, then go with the TF-3T6.
I use that one for day-to-day ops, coz it is not designated as a shelf queen.
Damn, one day really must find time to solder the 3-mode direct drive DRY driver into the Fry Ray 3800. LOL! It has only 1 mdoe now, ie Direct Drive. Then i really can play around with it and whack the living daylights out of it.....i have too many spare drivers. (I am using the Trustfire 1 x 18650 extension with it so that it does 3x18650)
Well the way I see it is the TR-3T6 is a proven light, the 3900 has a crap design drop in that's srewed into stainless steel that's just dumb, then you have to wrap in in foil to improve heat soak, with out the foil it is easy to see it would drop even more lumen's and quicker, then the proven TR-3T6 and since the dry need,s to be pack in ice (your words) to run for any lengtht of time in turbo mode the TR-3T6 with its buck + boost CC driver is the best choice in my opinion still, I would not even bother with the skyrays so yeah I'll buy my old man a TR-3T6 as my TR-3T6 is still going strong and it is easy to get parts like drivers, battery tubes, switches and bezel's not that I've needed any
Nice looking light! I don't care for the drop-in screwed to the bezel, however. Just personal preference.
Will be interesting to see if it holds-up.
One note about the FryRay 3800; if the tailcap switch is left on, and screwed into the body, intermittent contact while screwing it on will fry the driver pronto, from spikes/transients. Just ask me how I know this!
The resultant ZZZZTTTT!!! Will get your attention, as another forum member reported, as well.
Heat is its killer, as well.
FryRays; just say no...
r1derbike, yeah for any light, i always make it a point not to screw it on while switched on, you'll never know how's the quality of the driver with regards to input power control (esp those accepting multi voltages).
Benckie, the DRY needs to be packed in ice when gunning in the highest mode, in the ambient temperatures that i am experiencing at night over here. I tried it for 10 mins at -20 deg C with no wind, no issue it gets somewhat hot though. But for non-flashaholics technically without "self-control", that's a bad idea for the light as well as batteries. Just a simple matter of drive levels, ie turn it down man there is a level on the DRY that has equivalent output level as the UF 3900/3T6.
Not sure how the Uniquefire 3900 does without foil though....but seriously I don't think any P60 guys run their Solarforces and XM-L drop-ins w/o foil.... It's still better than an absolutely free floating drop-in.
I'll probably do a 15 mins 0kph wind @ 30 deg C acid test some time soon....to satisfy everybody. 
Even the massive TK70 got pretty warm at 10 mins, but the drive level is quite a bit higher of course.
Will try to get some sandpaper to expose the aluminum on the anodised threads, that'll help too. Fun hobby eh...
The TK70 would be the go, but for my old man the TR-3T6 would be the safe bet. Soon here we will the in the 40 + degrees C (105 F) days and warm/hot nights and if he takes it to work in the mill's at work at the power station it will be bloody hot. I tested the TR-3T6 for 60 mins on High in a stinking hot shed with a small desk fan goingswitch out no foil or thermal paste so it should handle it.
Wow...if it's in a warmer than usual kind of usage environment, then better don't even stress the TF-3T6 and run it on medium, which is about 700 lumens OTF.
To get 700L OTF with a regular single XM-L emitter flashlight like X9 or STL-V2, you will easily burn it up past 30 minutes in that kind of environment without airflow past the light.
Benckie, i think i found something that we did not consider before. Seems like the when both flashlight hosts are heat saturated (hosts are hot and not much cooling by wind), the difference is very little. This will happen, because both light's surface areas are the same. It is only when you can wick the heat from the Trustfire 3T6's host that the heat from the drop-in would be able to be wicked out. Else there is little difference.
30 deg C, 0 kph
Uniquefire 3900 (8.7% drop)
40s - 61.8
13 mins - 56.4 (previously 58.0 with wind)
Trustfire TF-3T6 (7.8% drop)
40s - 57.7
13 mins - 53.2 (previously 55.5 with wind)
The temperature of both hosts are about the same, 45-47 deg C..
they both did well i thought the 3900 would drop around the 15-20% mark easy but i quess the foil is helping and do its job
Still, couldn't decide. I'd buy a Sky Ray L1 for $95 but as far as they appeared to be Fry Ray's I guess I'll step back to x3 lights.
FandyFire's are said to be tweakened to lower currents in the late batches so I guess it won't feed me much. Everybody rates TF 3T6 high but it looks like a common design and the body isn't appealing after my two TR1200 bodies. And this UniqueFire is although nice, seems to work only with 2x18650 batteries.
Let's say, I have about $100. Which multiple T6 light would you suggest?
Anyway, I read the whole thread again and thought again if I’d use 3t6 with 3 cells. The answer is mostly no. I share Mr.Admin’s feelings about the TR host and I understand UniqueFIRE has better estetics and build quality. So, everybody still recommends lightmalls? I may order one tonight.
You can get the TR-3T6 in 2 x 18650 form only it's cheaper, it is a very common host some say it's dull but the way I look at it, is this it is very easy to find replacement parts cause its common, you can buy just about any TR host and the battery tube's, bezel, glass lens, tail cap and switch will fit it, the drivers are easy to find and you don't have to spend $55 buck on it and add foil.
I know what you mean. I also have built two TR lights myself. I just ordered UF 3900. I mean just a second ago and than I saw your post. I hope I did the right thing, because as you also have stated, 3T6 is about $7-8 cheaper on lightmalls.com
Still, I needed to have something with different looks, or I can't realize that I bought something new :)
I hear ya
I really like my UF 3900 from Manafont. I think it's a nice choice.
You said you needed a multi xm-l light that looks diffrent to the usual dull multi cell lights like the Tr-1200 and TR-3T6.
Well here it is, i just brought one.
As soon as it get,s here ill do a review and some long run time test, range test, current draw and i might even have to pull out the new lux meter.