BLF style 18650 1s thrower( poor mans Olight M2X)

Unfortunately, the orders take at least 2 months here, will have to wait quite …….

Has somebody measured the (inside) diameter of the reflector openings?

With those I could calculate some throw figures.

Ok, I now know the the diameter of the large opening, 52mm. The unused portion at the bottom seems to be around 15mm.
So the size of the reflector is 1948mm^2 as seen from the hotspot.

Under perfect conditions with good Osram Black Flat at 4.5A (250cd/mm^2) and a UCLp lens when turning the light on 425kcd should be possible (5-10% less after heating up). Of course this requires a linear oder Buck Driver (2S) and a lot of time and money.

With de-domed XP-G2 S4 2B (old, good one) at 4-5A (around 180cd/mm^2), FET-driver, normal glass lens and heated up maybe around 276kcd.

Interesting…
I never liked to many calculations and frankly speaking I really hate math. But I also know that plenty of engineers and scientist are on this forum so I really feel like a redneck among this guys :slight_smile:

But it would be interesting to know such calculations. BTW you talk about de domed xpg2s42b, and I am not sure that any of us have proper equipment for measuring cd/mm 2 so I just wondering how reliable that measured 180cd/mm 2 is?

Anyway I am still waiting 26mm mcpcb and I will report about old XP-G2 S4 2B performance although I did tested them and it seems that 4.4A(or lower) is max with curent batch of 9 pcs I have and with fet driver.

I expect at least 280-300. But as I said I will report when my pcb’s and new lux meter arrives.

Djozz tests are always Holy Bible to me. But I guess in his test of mentioned emitter he probably did not got the best one. So I am very intrigued now. Cause this is obviously new thrower king… Tiny (dd XP-E2 size) but obviously working.

So another question is what kind of current draw we can expect if we use a FET driver with it? Djozz did direct drive mode but what is the difference if I use artic alumina as insulator and fet driver?
I really don’t understand… That why I will ask you guys :slight_smile:

180 is based on a reliable, measured value at 3A (145-151cd/mm^2). So I adjusted it for a higher current (same as with lumens, see djozz tests). But of course, it is not perfectly precise because with FET drivers the current changes all the time. So here it is just a ballpark figure.

The 250cd/mm^2 of the Osram is also a reliable measurement, it might actually be a little higher bcause not alle the optical losses of the test setp where accounted for. So this value just shows what is definitely possible. Not all Black Flats will be this good. Some might be worse, some might be better.

The_Driver, has the luminance of the dedomed XPG3 been measured?

Yes, here. sma measured an XP-G3 S5 @5.05A with and without dome (he shaved the LED with a shaving blade and some silicon lubricant).
With dome: 88cd/mm^2
shaved: 186cd/mm^2
So it’s actually much better than people think. Especially if one takes into account that it can be driven at much higher currents.

I did a similar measurement of the bare die and got similar results. The problem is when the dedomed XPG3 is actually put in a flashlight (reflector or aspheric) the resulting lux is much lower than the dedomed XPG2. See some measurements on this thread: Cree XP-G3, testing a S5 3A emitter - #71 by FmC

I still don’t understand the discrepancy between the different measurements (in and out of a flashlight). See here for some discussion: Dedomed LED Tints Compared: XP-G3, XP-G2, XP-L - #84 by EasyB

But the fact is that no one has modded a light with the dedomed XPG3 that throws nearly as well as the dedomed XPG2, even with the increased current (lower Vf) of the XPG3.

The problem here is that we don’t know how those people built their lights (maybe the focus was off?). We don’t know how they de-domed their LEDs (maybe they didn’t remove enough silicone or maybe they damaged the phosphor). We also don’t know how consistent the luminance is after de-doming (probably not a problem though).
Maybe sma made a mistake in his measurement.

So in the end we don’t really have enough real evidence either way. I can say that sma has a lot of experience with luminance measurements and that in the past his measured values pretty much always correlated with measured throw of different lights.

I think the problem is that a few people tried this LED and then wrote negative things and everyone else gave up.

Also a lot of people have started building unregulated lights with FET drivers. This poses the risk of damaging an LED when turning on a light because the startup current can be extremely high when using these new low-Vf emitters.

Controlled tests must in my eyes be done with constant current.

Interesting points. :+1:

Would be nice if a “how to” topic was here about ‘shaving’ modern LEDs.

The_Driver, those are plausible explanations. I would love for the XPG3 to meet or beat the XPG2, but I’m doubtful. There are several examples of experienced modders getting similar underwhelming performance results with the XPG3.

I did extensive testing on the XP-G3 when it first came out, with MEM assisting. I found it to not meet the capabilities of the XP-G2 in a reflectored light although MEM found promise with aspheric builds.

I do not like the beam profile from the G3, domed or sliced or de-domed, so I don’t use it.

Very interesting. MEM really believed that XP-G3 will kick ass but than he disappeared.

This is his de domed emitter(yes he even managed to perfectly dedome G3) tint comparison test in reflector light Dedomed LED Tints Compared: XP-G3, XP-G2, XP-L

Or to make it short I will put interesting pics from his thread:

XP-G2 dedeomed

XP-G3 dedomed

See what I mean though? The blueish purple aura and odd spill color? I don’t like that, so I don’t use it. Not fond of the XHP-50.2 either, for similar reasons. Will eventually pull the three from my scratch built light and go with something else.

Back about 3 years ago, when the HD2010 was giving me these problems, I did this to solve clearance issues. Made it easy to dial up the focus without worrying about touching electrical contacts…

I was looking at this pic some days ago…

I really want to try this , but seems tricky of course :wink:

Yes, I agree with that.
Above I was just talking about center beam lux/candela, not all the other problems.

There might be a solution for this though. Somebody here on BLF did it with an XP-L2. After de-doming it he cut away all the excess phosphor. This way he got rid of the yellow-green corona.

The blue spot can probably be fixed by starting with a lower color temperature LED before de-doming.

It’s not so bad, the first “trick” is to get the rectangular shape of the thermal pad cut into a copper box, then match it width and height with some sheet for the electrical contacts. I cut slightly shorter strips from a coke can as aluminum doesn’t solder. Placed like 3 strips between the sheet and pillar, held them with a small clamping tweezer (might have been a hemostat) and placed the assembly on the Noctigon with solder paste present, solder paste on top of the copper as well. Then I put the emitter on top, re-flowed all of it simultaneously.

I did it to the XP-G3 in a Courui D01 when they first came out, it helped, but it did not improve throw not one bit. This had .005’ silicone left over from shaving. I made up ground washers with different thickness’s .005’’ increments, to shave as close as I could.

This is what happened when I went to the next .005” smaller washer! :smiley: There was still a bit of soft mushy phosphorus left, kind of thin though! :person_facepalming:

So close and yet so far! What was amazing back then, when they first came out, was these G3’s were pulling 8+ amps, it got very exciting, but yet I was only able to achieve 270-280kcd IIRC in the Courui.