First Post / First Build

Flashlight Modding and DIY Parts
1

Howdy Folks!

I've been poking around BLF for a while now, getting ideas on which parts will work for my needs, and finally ordered from Mountain Electronics (haven't arrived yet, so obviously I'm itchin' to get started ).

Here's what's coming:

Host: UF-1405 Zoomie (2*26650)

Driver: Qlite 6V + Zener mod, with 8*7135 added

Emitter: XHP70 N4 3B (6V) (Rated 4,022 lm @ 32W)

I studied Cree's data and test results from pommie, and came up with the following:

-The driver supplies 3.04A, plus the 7135's (at ~0.35A each), so 5.84A total,

-According to the graph linked below (posted by pommie), at 5.84A I should be at roughly 6.67V across the LED leads (my best estimate),

[quote=pommie]
!https://farm8.staticflickr.com/7567/16071892179_7d89411e10_o.jpg!

-5.84A * 6.67V = 38.95W

-At 5.84A, pommie's graph shows ~4.200 lumens. (Since I'm almost 7W over the LED's rating, that sounds reasonable I think).

-Cree states the min. luminous flux @85 deg. C = 1,701 lm (I'm interpreting this as similar to OTF lumens).

So, if 32W works out to ~1,710 flux, proportionally at my expected 38.95W I should be at about 2,081 flux. Since the lumens per Amp trend downward as amps increase, I rounded down to 2,000 luminous flux.

Now, I know this is certainly approximate, but I'm wondering if I'm pointing in the right direction with my logic. Any input is appreciated. Thanks for reading!

-Ayloxs

(I'll work on photos after everyting arrives )

2

Welcome to BLF!

I’m not the best to critique your proposed build but it seems good to me. The 1405 is a very popular host.

Phil

3

Welcome to BLF Ayloxs! I’m not sure about your calculations. Sorry. But, it sounds like you’re gonna have an awesome build there.

4

Thanks for the replies. This was just curiosity, since I don't have the means to measure beam brightness. If I ever find someone who can, I'll resurrect this thread

5

Welcome to BLF!
You seem to have thought your build through carefully!

6

The first thing I saw is that you’re assuming 350ma 7135’s were being added, while I always thought Mtn used 380ma chips. If I’m right, that would be 6.08A total.

But I checked and the sales page definitely says 0.35a per chip

7

I think last time I looked, he offered a choice to upgrade to 380mA chips for a small price increase.

8

Min luminous flux isn’t the same as otf which includes losses from reflector, lens, etc. from djozz’ tests the Mt-g2 should give you around 3k otf lumens at between 5.5-6A.

9

Yeah, I also noticed that most on Mtn are 380mA, and since the ones I'm getting said 350mA I re-checked my numbers in case it's a typo. 6.08 is still acceptable to me...although either way I have a feeling she's going to heat up fast at 100%. Thanks for the fact-check!

10

I suppose that really was the question - whether luminous flux and OTF are similar - so that helps. Now, regarding the test from djozz, the MT-G2 is rated 1,987.5 lm @ 3a (6V). If it'll give ~3,000 lm OTF at ~6A, then I'm REALLY excited to see what I've built

11

Curious about the choice to put an XHP70 in a zoomie…

12

Is there much choice if you want as many lumens as possible from a single emitter with two 26650’s, there is the MT-G2 which shouldn’t get quite as hot?

13

Well, if the cross ever bothers him, he can just slide the zoom back a little to obfuscate it.

14

Find a way to shim it so the zoom stops just short of complete focus… :sunglasses:

15

Yeah, that too! :wink:

16

While indeed I'm expecting to zoom back a bit to omit the cross, and I do like the shimming idea, I'm amused at the prospect of being able to project an 'X' onto clouds. This will be mostly used for flood, but sometimes the tight beam is nice. Besides, I've always wanted a light saber...

17

Hi and welcome Ayloxs. Post back how your build goes when your finished.

18

Sorry, according to another djozz test(for which we are ever grateful) the N2 XHP 70 does 4K lumens at 6A. Probably not otf and you’ll want a reflector that blends the separate die images in the spot like the ledil Iris but it should be bright even with the N4.

19

Certainly will!

20

Are you saying I can use the Ledil Iris in addition to my lens, or do you mean switchiing to a non-zoom host?

Also the "even with the N4" confused me - it seems like the brightest bin available for this LED. Maybe I'm not understanding.

Edit: I was wrong, P2 is brightest, N4 is 2nd. Again, unless I'm not looking at this the right way.

But this (chart at top of pg. 15):

http://www.cree.com/~/media/Files/Cree/LED-Components-and-Modules/XLamp/Data-and-Binning/ds-XHP70.pdf