BLF GT (preliminary) modding thread

Yes, I am hoping they do as well, if these numbers hold up I am guessing they will, even I am shocked at these numbers if they are real.

I would not believe them if I had not seen them myself and I still doubt.

I am interested on the MCPCB with 70.2

I am interested in modding my GT with a 70.2. I will purchase the parts if they are made available…

Guys, how hard is to replace bottom part of GT, where battery tube goes in?
Mine is broken, Lumintop offered that they can repair that or I can do it by myself.
Mike

Well, it is very simple, you just unscrew the head and then screw it back on the new light engine.

The hard part is getting the head off. You will need a strap wrench almost assuredly. I was able to get one apart without a lot of hassle by loosening the bezel first and then the head. I carefully clamped the light engine in a vice to do this.

some are much harder to open though.

I would try opening it first and see what happens.

I noticed on CPF that Vinh is in the process of modding a BLF GT.

His modded one will use XHP 35 HI emitters arranged in 18 quads … 72 emitters total! :+1:

Vinh’s 72x XHP35 HI BLF GT

I guess he is bored with CFT90 mod now.

He’s said before he cares more about lumens than throw.

My prediction is that is going to cost around $20 per emitter… :open_mouth:

He says reflectors waste too much light outside hotspot, so he likes tir. That could be why he choose not wasting lumens over throw, but i think he likes throw, so he must build massive world record flashlight output of lumens in order for tir to throw as much as it can.

I don’t think it will be lower than $30 per led. His goal for Sirius is 80000lumens and 600kcd.

These pictures may help.

Post 61 had some more pictures.

Well, My dr meter showed up today and I was able to get some readings of the XHP70.2 GT’s along with some crude beamshots. I will post the results tomorrow but I will just say I am not disappointed in the slightest.

Do you have a stock gt to compare pictures with? Can’t wait. Real lookin forward to hearing and seeing the results.

Good, good! Looking forward to the beamshots and measured throw data.
I’m quite happy with my GT but to be honest - a light this big could have some somer POWERRRRR………………. 8) 8) :sunglasses:

I thought about giving it more throw (for instance a black flat) but the tiny beam of few lumens out of a light this big, I don’t know :question:

Cheers
Nico

Ok, here are the results of my testing with the Dr Meter LX1330B lux meter and the XHP70.2 GT.

These readings are at 10m, outside.

First the stock GT for a reference point.

- 1.1 Mcd for a total of 2100m of throw

Next up is the XHP70.2 80cri GT with dome on

- 560 Kcd for a total of 1500m of throw with over 9,000 lumens!

Lastly the XHP70.2 80cri GT with sliced dome

- 750 Kcd for a total of 1725m of throw with over 9,000 lumens!

So needless to say I am pretty happy with the results. A P2 bin XHP70.2 could most likely get a bit more then this but I didn’t have any on hand when I put these together.

Here are some very crude beam shots that kind of show the difference.

Dome on > Dome sliced > Stock GT

Stock GT:

XHP70.2 sliced Dome GT

XHP70.2 dome on GT

I am officially listing both of these lights for sale and I can swap the LED to something else if someone wanted.

I will post a thread for them later when I have some time.

wow, thats it here since 4-27 on this mod ?

I would of expected more response as well but the beamshots are really not that good so I can’t blame people.

I have not looked into this thread much, but today I have time to work on my GT.

Those are very nice results for the sliced XHP70.2, TA! Those beams and numbers show that the maximal driven XHP70.2 makes for an extremely valid mod.

Today I’m going to try to improve my GT. It under-performs by quite a margin, a few weeks ago I checked my GT together with Nicolaas’ GT and while we measured 1.16 Mcd for his GT, mine did under 0.9 Mcd. It did not seem to do with the reflector or focus, the hotspots of both GT looked good and very similar (but his tint was considerably warmer btw )

As a baseline before opening the GT up, I measured the throw again in shorty setup with 4 charged 30Q’s at 30 seconds and 12.41 meter (the longest distance I can measure indoors), and got 875 kcd.

For the general good I checked my Tasi meter and LX1330B meter as well for the GT hotspot, and thanks to the neutral tint they read quite close to the MobiLux, for the GT hotspot the Tasi reads 2.9% high and the LX1330B reads 2.4% high. That is pretty usable.

To be able to check the led current I pulled out the minus-wire but also had to add 25mm of 18AWG wire for the clamp meter to fit. The ledwire itself is long and 20AWG and at 2-2.5 A the added piece of wire should not have measurable influence (and the current should be regulated anyway).

I checked with both single tube (4 batteries) and double tube (8 batteries) and the current was the same: 1.98A at start, 1.96 at 30 seconds, slowly droppung, at 3 minutes (double tube) it was 1.88A. You’d think that the batteries provide enough juice to keep the current level at 2A for more than a minute?

But what seems wrong to me is that a double-click does not give 2.5A, my GT sticked to 1.96A however I tried the double-click: a brief ‘off’ and then back to 1.96A. A factory reset does not solve it.

But that is not the only reason for my low performance: the XHP35 Hi (Koef3’s test) has a 1.11% output gain from 2A to 2.5A, so if ‘turbo’ worked in my GT, the throw should go up to 875x1.11=971kcd, if measured like others do with the LX1330B that would read 995kcd, still on the very very low side of what the GT should be capable of.

So with the hotspot looking good and correct size (no focus error), there are at least two things under par with my GT: turbo seems not to work, and either the reflector is really poor (looks worse than Nicolaas’ reflector but not terrible) or the led underperforms (too hot reflow perhaps?). I can not solve a reflector problem and I can not solve software/electronics issues, and ordering a new led takes a few weeks, so I’m afraid that I’m done for today :frowning: