Fenix TK61 teardown and mod thread

Finished up my first mod on my tk-61 did a gasoline de-dome and resistor mod. Everything went great super bright and an amazing throw. Never would have known about modding this light if it wasnt for blf. Just want to say thanks to everybody wo shared information with me.

Hi guys, some tips how to center the emitter/reflector on the TK61? i heard its very hard, and if the led is not perfectly centered you could lose like 15% of the CD, is this true? Sad

It’s a wonderful feeling when you amaze someone like this. Showing someone who’s used to Energizer lights which have one LED and a little aspheric lens a light pushing 1km in throw always blows people’s minds.

It makes my hair tingle with joy whenever I read this. (Okay, I’m weird.) XD

Did you end up leaving the dome on? Any idea of kcd and lumens with dome?

At 5.75A with dome ON it gets 330-350kcd at around 1900 lumens.

So how does 350cd translate into meters?

My guess is 25% bump from stock? or around ~ 1050 meters?

Just note that it’s 350,000 cd, not 350cd

to 0.25lux it’s square root of 350k*4
= 1183 meters.

Realistically you won’t see things at 0.25lux though… More likely 1 lux which is half the distance.

Thank you. Useful light would be around 1/2 of that i guess? so 600 meters should be a good distance?

Yeah around 600 meters. Below 1 lux with the naked eye it’d be almost impossible to see that far out. Also a thing to remember is 4x the candela = 2x the throw due to the inverse square law. Eg. a 100kcd light will only throw twice as far as a 25kcd light.

Yes i read on CPF that you need 4x cd, to get 2x the throw, thanks!

If this question is still open:

Do you have a specific reason for trying the 70N02? A quick look at the datasheet reveals that it is not designed for low logic levels on the gate (I don’t know what the logic level on the TK61 is). It will not be the optimal choise if the logic level is under 5 V, as it will not open fully. Also, wiring out transistors like that from a DC/DC converter may result in some crazy EMC/functional issues… :slight_smile:

EDIT:

For a good N-MOSFET, you could try this one. It seems to have a very good price/performance ratio, and it will fit into the PCBs standard footprint (sot-23).
http://www.mouser.com/ds/2/115/ds31946-65244.pdf

I had it available in front of me and was curious. Wanted to help RMM to push the stock driver. Unless the stock driver could do extreme amps I was moving on. And it seems it could not nearly as many amps as I had plans for.

Ive finally got my HX-1175B drivers yesterday (only 64 days after I first ordered them), so Ill put one of those in my TK61 like I had planned ages ago. Seems like others have already beaten me too it.

Currently got some other projects that's been moved higher on my to do list. I think you guys might like one of them, ill share if if successful. But this time I want to finish my own project before sharing details.

Ill update this thread later on with how I did my TK61. Might compare with Supbeam K50 too.

Thanks for the tip Samppa. Welcome to the forum btw! :) Always nice to have people with some electronics knowledge helping with mods!

Gotta tell. Just got in from playing with the TK61 and my latest psycho bright light. (Similar size as TK61). Awesome stuff! Regular car headlights look like old incandesent Maglies in comparison. :D

Thanks! Your super flooder with 12 emitters looks amazing! :slight_smile:

I’m always interested in extreme mods, both flood and throw. I have the TK61vn which is supposed to throw around 600kcd, but I’m already got used to it… Need something even stronger soon!

FINALLY, after 4 + months waiting, and pain, my TK61 is dedomed properly! and compared to the first mod, when the light was loosing from TK61 stock, (dunno what went wrong) this time, the light has exactly 2x cd!!!!!!!!! so happy now! we measure double the cd 5 times in a row, 10, 15, 20, 25, 30m!

Next 3A> 5.75A, stock paste > Artic Cooling MX4, copper heatsink added 2.5mm, led perfectly centered and so on :slight_smile:

After a long wait :slight_smile: As achievement give 5.75A to the led?

I didn’t tested, will replace the parts in few days, but i got the exact same parts as Vinhn, so it would be around 5.7 or 5.8A.

On a sidenote. Have you measured 4,7A to each emitter in your TK75??

No, but again using the exactly same parts as other user who reported 4.7A, so i guess its 4.6/4.7A?

I will measure both of them in few days, and report back.

Looking forward to hear the results.