Luminus SFT40 test

:blush:

Does Anybody know what is going on with the availability of this led? it seems to be rather disappearing then getting common.
Can it be such a huge demand on the market so everybody has sold out?

It was there, now it's gone. Dunno why but seen this before with new LED's. First batch goes quick, no 2nd batch for a while.

I only knew of one place to buy them - Convoy. Don't think KD got them at all, and Cutter doesn't carry the Luminus line of LED's, and Hank just doesn't list many LED's he will sell to us.

This is the most interesting emitter lately so I don’t doubt that Hank or Simon will stock it soon.

I seen from the thread that plenty of guys have those Black Dots Of Death or BDOD… That will led to emitter destruction, and not to mention you can’t sell that kind of flashlight to anyone(if you are seller).

So what happens here? Hot flux particles mixed with some solder particles explode into silicone protective layer of led emitter(situation when you flux contact pads, and then you do final touch up with rosin core flux solder wire). Certain flux(fluid, pen, paste) “explode” more or less and permanently bonds with silicone and even worse if it penetrates enough into phosphor… GAME OVER.

I got one flux pen from premium brand and that is the worse one I have. It literary explodes each time i touch it with solder wire. I guess this happens when incompatible flux like rosin core flux in solder wire and lets say generic liquid flux meet each other on solder tab. So proper flux combination needs to be used or to not use flux at all(i always prefer flux).

The key is in protecting emitter from hot FLUX splash. I use some kind of small lens over emitter for that purpose but you can be creative and think your own way of protecting emitter. Some kind of protective barrier. While isopropyl alcohol can help if it did not penetrated deep enough it is better to not let anything happen to emitter.

When you do whole process by yourself (reflowing and soldering) you have full control, all the time in a world and you can only blame yourself for fail. When factory makes light which workers are timed to make certain minimum order quantity per working day you can really expect problems.

Woow, thanks for explanation. Anyway I want them :innocent:

Badly :smiling_imp:

I’d recommend using the 5050 9mm gasket with tape covering the center while soldering and repeatedly cleaning with cotton swab and ipa before first turn on

Hhmm. Did a 3X21A triple SFT-40 mod, cranked up amps I suppose with FET+1 driver, 16 AWG LED wires. Smoked one LED badly (BSOD) and a 2nd one mildly. Mistake I made was trying 30T's, took under 5 seconds, saw the output drop and quickly shut it down - was too late.

Swapped my "good" 3 SFT-40 MCPCB into the bad one, now using P42A's and 50G's -- all good. User will be using 50E's so even weaker, so should be fine.

Maybe those did have contaminants on them.

I gave one emitter 9,5A’s from LD-4A and it developed black dots. It worked fine with 8A. Dot’s came off with electronic cleaner that shouldn’t hurt plastics, but beam turned purple. I mean really purple. I had black dots in my vision after beaming white wall for a minute. :smiley:

I guess that I was lucky with the test-led of the OP, going to 20A and back without black dots appearing?

Hmmm…. We have many BSOD reports since opening of this thread. I don’t remember we ever had so many reports in one thread before :question:

The silicone layer over the phosphor is relatively thin (like compared to the XPL HI), so maybe that makes it more sensitive to flux splatter or debris?

It is good practice to wipe the LED with isopropyl after any nearby soldering. That splatter gets everywhere.

Yea, but I did a few mods with these and the modded lights never had a problem: TK-35, BOSS1, FF SP03 triple, BLF GT.

Think you guys are right about something getting on the surface of them. They are actually difficult to get things off of - the dye surface is in a depression, the edges are higher.

I actually don’t think there is any silicone layer on the phosphor at all. Its very soft and porous, especially compared to osrams, which almost look like they have a ceramic or sintered phosphor layer.

I can come back and report that my quad SFT40 light is still doing well. I cleaned it up with a Qtip and alcohol. The black spots became lighter in color but I wasn’t able to completely clean them off.

Since that time, I’ve ran the light a lot at even higher currents using 3*Samsung 30Qs instead of the 3*Tesla 18650s that I used before. There is no noticeable depreciation.

As stated above, I’m also inclined to believe the surface of the SFT40 is especially sticky for debris or flux splatter.

No BSODs on my only SFT40. Only to add to the statistics. Hope they’ll be back in more CCTs.

IIRC Osrams actually do have sintered phosphors (which gives them better thermal conductivity).

Just for the record, I’ve tested 2 SFT-40 as for now. Both had one dark dot. In one i have scraped off the dot creating a little crater on the surface. There’s a more violet area in the beam but visible only when zoomed out max.
The other one still has a dot, but so far works fine.
Both were purchased at KD.

Actually, there is some damage to my emitter which had the darkest black spot. I switched my light to another mode group today to get moonlight and found that the right-most emitter has some blue leaking from the right side (see pics). The blue is also noticeable in the beam if you look close enough. I’m a bit disappointed since I don’t think any emitter has had more than 7A, though it’s one of my only lights which I can’t test the current on. It’s not a huge deal but it will hold me off from buying another SFT40 light. I’m probably going to wait on ordering a Jin Heng JKK90 until the SFT70 comes out.

Its any news about this LED? I still waiting for my order. I must receive LEDs in few days. Maybe I will use 7pcs of this LED in my best headlamp. It will be crazy. :smiley: But maybe not better as OSRAM CxLPM1.TG.

Ohh Kayy… So you’re meaning to put some 200+ watts onto your head? Drawing some 40+ amps?

Maybe you meant car headlight:

I don’t believe there’s any provision to beef that up to a couple of hundred watts. Sorry I couldn’t find a 7 LED array.

As for throw, no beam shots or tests as yet been posted. I’m assuming you are referring to the CSLPMs or CULPMs.