BLF GT (preliminary) modding thread

I received my GT a few weeks ago. I love the light, especially the 4000k tint. My LED was slightly off center due to some very minor slop in the centering apparatus. I wanted a way to get consistent centering of the LED. To address this, I spent some time filing down a centering ring to fill the void. It did not come out perfect, but I am satisfied with the result I got, especially considering that I only used hand tools.

The head was VERY tightly screwed on. Removing the head was the most challenging part of this project. I had to make a crude strap wrench and clamping fixture to loosen it. I have not removed the bezel yet and am not sure if I will attempt to.The reflector is a tad bit dusty, but it does not really concern me. I lubed the heck out of the head before putting it back on (visible in photos).

Here are some size reference photos next to my ‘other’ superthrower. The GT is absolutely massive. The lux meter goes back and forth between the 2, so I estimate they are about the same in terms of throw. The chrome light is a Fivemega Elephant original with 3 series 18650 carrier, DX 78mm aspheric, wavien collar, modified h22a heatsink, xp-g2 s4 2b (old style), driven by TaskLED h6cc at 5 amps. Plans are to install an Osram Synios fairly soon. The GT will most likely remain stock other than the centering ring enhancement.

That elefant deserves its own thread :wink:

I like both! :+1:

Did you mod the Elephant yourself?

Where did you get the wavien collar from?

I did build the Elephant in 2014, back when wavien collars were available for purchase. I’ll post a thread when I upgrade it. Thanks!

This evening, I swapped the stock 4000k XHP35 HI with a 5700k XHP35 HI D4 bin.

This is the same LED being offered by MTN for transplant, for people who don’t like the stock LED.

Using 8*30q’s fully charged, I calculated the following readings (to 0.25lux), using a CT-1330B light meter.

Taken @ 10 meters – 1833 meters throw.

Taken @ 15 meters – 1849 meters throw.

Taken @ 20 meters – 1841 meters throw.

Compared to the stock readings;

Taken @ 10 meters – 1760 meters throw.

Taken @ 15 meters – 1764 meters throw.

Taken @ 20 meters – 1743 meters throw.

While the GT is a great thrower, & will wow most people, unfortunately it falls short of the “>1 Mcd (ANSI throw >2000 m)”, as promised in the original specs, which is a little disappointing.

Of course, I’m just using a cheap, un-calibrated meter, so there’s bound to be a little give or take in the numbers.

I’m looking forward to see what it can do with an XP-G2 :slight_smile:

EDIT – see post #68 – possible faulty meter.

Have you ever measured other lights with the same meter? Were the readings also low? I find them very hard to believe.

Yep, I have a large spreadsheet of measurements from other lights, taken with the same meter.

I’ll dig out a few other lights to re-measure, in case there has been a change in the meter, but in the past it has been in the ballpark for other known lights.

I don’t see anyone else posting throw numbers for their production GT’s, though. It would be good to see a comparison.

CFT-90 is more efficient than the old SST-90
50% more current

Kawiboy confirms that Lumintop SD75 board with XHP70 footprint fits and will be available for modders soon

I made drivers modded for more current and even the stock driver needs only a few parts added or changed to fuel an XHP70 with 70-100W

Yeah, I also want them to make an MCPCB.

For the driver, you could use an existing TA driver to get max power right now and I am thinking about making a new driver for this use case as well.

I have the parts here to try the 3V mod. The stock driver will actually drive a 3V LED at the stock 2.5A current, it just can’t handle much more then that as the stock diode will quickly overheat.

Keep in mind that the meters we use favor CW emitters to NW. I generally see about a ~10-15% difference in readings from equal bin emitters of different tints.

So that would actually put both emitters at about the same throw level with that factored in.

Although the total readings you are getting are a bit lower then most, not sure why. High humidity, smog and other factors play into things and since your 20m readings are lower then your 15m readings this leads me to think this is the case for you. Most see the highest readings at 20m.

For example VOB got his 1.29mcs reading at 20m with lower readings are closer distances.

All that said, I can’t say for sure one way or the other. Just theory’s.

Not a mod to the light, but wanted to share my method of sling attachment. I used:
Black split rings
Adhesive lined heat shrink tubing (3 to 1 shrinkage)
Kevlar trip line (80lb. test with good abrasion resistance)

Heat shrinking the split ring prevents scratching and noise when contacting the light. The Kevlar line has been good for other uses, so I am hoping it will stand up to the wear caused by the edges of the attachment points to the light. I made the loops long enough to double up when attached creating mass and reducing slippage and movement. Used simple cows hitched to connect to the light and to the rings.

Works well so far.

Thanks for following this up.

Can you give some more specifics on the 3V mod parts? I’d like to set it at ~5A for XP-G2. I have plenty of resistors & other components kicking around, but possibly not the correct diode by the sound of it.

I’ve just dug out a couple of lights that I had throw #’s written down for;

A K40t that read about 8KCd less (312/320) than last tested, & a modded XHP35 HI light that read about ~20KCd lower (~490/510) than last tested.
So by the looks of things, the meter could be reading progressively lower, the higher it scales. (yes, I’ve already replaced the battery :slight_smile: ).

The meter is a few years old now, & has had plenty of use, so I might order a new one.

Afiak, the linked sst90 die is the same as the cft90. Only the package is different.

I will post the complete parts list once I test it. We picked out a few different components to try so there is some testing involved. Just have not figured out a 3V LED I want to use so bench testing will be what has to happen I suppose.

It should be able to just handle 5A @ 3V though with the upgrades.

I also noticed that my meter started reading a bit lower on lights I had measured previously a few months ago. Maybe that is why they provide caps for the sensor because they wear out?

Another factor is that since your numbers were dropping by 20m, it is very possible that the atmosphere around you is in part to blame. If there is a higher particulate in the air it will reduce the readings, particularly at longer ranges.

What may I ask is that other super thrower ?

The other light I was referring to is this one.

Not commercially available…. :smiley:

Nice, but I was curious about that silver one…

Nope, the SST-90, SBT-90 and CBT-90 are the same technology. They are from 2009.
The CFT-90 is new and much more efficient at the same current (around 60% at 9A). In addition to this it’s rated for a 50% higher maximum current (27A vs 18A).

Where did those guys who ordered massive aspheric lenses from optiform go!? :smiley: