TN42lx and GTlx with CFT-90, first tests and assembly

Flashlight Modding and DIY Parts Featured Mods
1

I started this idea a while back pretty much same as Skylumen

I put it not on high priority and a lot of time passed without any progress

I have now tested the first driver thats function works as expected, still its a prototype which has a too high standby drain,
I need to get someone implement a Enable output in NarsilM to be on while MCU is awake and off when in sleep
as it is now the buck chip and temperature sensor reference voltage east a few mA which is not acceptable for me

So lets look at the driver design for the prototypes
GigaThrower

TN42

LED mounting the GT is easier than in the Tn42 as I can open the head close to the LED

first get those connectors off them, not easy as the LED- is as well the copper core
So I decided to destroy the plastic part and use a 30000°C gas burner to get it desoldered which worked

Unsoldered

Integrating in the GT

marks for drilling holes and make M2.5 threads

M2.5 screws fit nice, my M3 are too high
Also drilled two 6mm holes for wires

The centering bar in palce it was sanded about 0.7mm to get the LED in the focal plane
I need to glue later the scres from it as they are not fixed

soldered two times 2x1.5mm² silicone wire, squeezed it flat and insulated with kapton tape, even if it is not as high as the centering bar
The centering bar needed to be trimmed a bit

head parts screwed to one piece

I put the LED on a 5A bench PSU for a quick beam shot, the focal point might not be ideal
This is the 6500K variant vs 4000K GT XHP35

Now to the TN42

Putting the centering piece on the LED

now marked its outer diameter on the LED board with a knive

Sanded the piece like the GT centering bar, and cut out the LED and temperature sensor

having a quick look on the reflector I am not sure if the gap to the LED wires will be enough not to make a short

Also the head needs electrical insulated from the carriers ground
So I made the holes bigger and will use Kapton tape around the screws and a plasic washer to insulate them

centering piece glued to the LED

Soldered 2.25mm² wires to the MCPCB and mounted it in the head
I made a Mistake and drilled 2.5 instead 2.1mm for M2.5, so I had to use nuts, but it works

I used my Dremel to got some material on the reflector removed, where the LED wires are and insulated it,
but it seems the reflector can rotate in the head not touching the LED wires, so for safety I will make this all around the reflector base

first test with my prototype driver

2

Nice job Lexel :+1:

3

Very interesting. Do you have any lumen and throw numbers?

4

Great job, looks like a pain in the butt to mod a flashlight with this led :open_mouth:

5

Nice job lexel… do you see any ring on the blf gt with cft90 ?

6

Skylumen got 5000 lumen and 1Mcd on the thrunite tn42 cft90 led…

7

I highly doubt that 1Mcd and 5k lumens is possible without cheating the lux measurement on a focal point with his 20A driver
700k is a more realistic number

after I have seen a video of him talking only bullshit I have no trust in his numbers at all anymore

8

The 5k lumens sounds like BS, it’s probably closer to 4-4.5k that actually leaves the flashlight.
The lux sounds right though, assuming he is stating the performance when it is first turned on.

After 30s the output will definitely have dropped.

700k is lower than what a stock TN42 gets with an XHP35 HI.

9

Great job lexel!! What did you do with the component that you de soldered from the mcpb? Do you add them to the driver? I saw that you also left one next to the led is their a reason for this? I would love to do this mod but it definitely takes skill and knowledge.

10

What an awesome build, Lexel. Really want to do this with my GT :money_mouth_face:

11

Lexel, can you explain simply why the CFT-90 needs a new driver design if it is a 3v led? Can’t a cheap, regular driver power this led?

12

Vinh tests his candela numbers at 10m iirc, so his throw numbers are usually a bit low. From what I remember he initially measured the GT at only 1.09m cd as opposed to 1.2-1.3m.

As far as turn on performance vs 30 second performance, I’m less sure on that one. I have seen him differentiate the two some times on his measurements for certain lights though.

13

DD is not really an option for an 115€ LED

14

What do you mean?

15

Can you measure the lumens once you get the TA lumen tube? That should put this to rest. I’m also very curious because the TN42vn90 is so attractive.

16

Nice work Lexel .

People asking about fet drivers : Yes , you can drive cft-90 up to 18-20 amps with a fet driver , for max potential you use a buck driver like these Lexel designed .

17

Sure I will. My lumen tube should be here next Tuesday. I hope it’s sonner.

18

Any updates (measurements) on these awesome CFT90 mods?

19

Lexel, did you also experience the bright ring of the CFT-90 in the BLF GT like V54? Or did you manage to get around it?
http://www.candlepowerforums.com/vb/showthread.php?446244-2018-Mega-Beam-Shots&p=5203080&viewfull=1#post5203080

Do you perhaps have long range beamshots between a BLF GT CFT-90 and other variations of the BLF GT?