Fenix TK61 teardown and mod thread

This driver seems to make big jumps with small changes. The bump up from 4.83A is what killed it. I had one running at 7.13A that seemed reliable, but I wasn’t able to get the throw on it that I thought it should be making, so I changed the emitter and poofed a few more.

Man, that's alot of xml2's to lose. I lost a bunch to a FT "3T6" driver once. It really hurts.

I know we are talking about it in the other thread, but whiles I'm thinking about it. Have you tied a different HX-1175 in any of these attempts?

I got 2 of these drivers. I’ve built 4 different control boards, was having all kinds of issues. Primarily at first it simply wouldn’t work at all. Then I discovered that the wires from the 2 e-switches break the standards. One switch has 2 red wires, the other has 2 black wires. I had it wired wrong. Then I started blowing emitters. Tried changing current and all that but of course I bought it BECAUSE it could run higher currents.

This isn’t the first time I’ve had something working and went for that little bit more… should have left it alone while in the 500’s in Kcd.

The problem lies in the top end output, as the other modes work fine and there’s simply not an issue until Turbo is clicked. Then it’s either making way too much power or it’s spiking and popping the emitter instantly. I don’t see fried bond wires like a massive overload, so it’s got to be a spike or surge. (Doesn’t have to be of course but that’s the way it seems)

I got some new sense resistors in the mail today so I redid the TK61 yet again. I cut a 40mm disc .9mm thick to go under a 20mm Noctigon with a de-domed XM-L2 U2 1D. Removing the stack of resistors I had on the driver, I put 2 of the new R070 that are even larger than the ones originally on the board (it came with 2 R068)

After firing up in Turbo at 6.98, it climbed to 7.13 and seemed to stabilize. I backed it down then came back at it and it hit 7.2A. With the light assembled, this makes 565Kcd and 1611 lumens at start with the light hot. Having the base of the reflector cut out to be able to fit over the 20mm Noctigon is nice, I simply dial the head up or down to find focus. Works really well! :slight_smile:

And here’s the inevitable “but”…I see a tiny black spot on the phosphor, so it’s gonna die. :frowning:

Here's a mouseover of the TK61 with XP-G2 de-domed at 5.5A (557Kcd) vs. XM-L2 de-domed at 7.2A (565Kcd).

Same camera setting, same spot...97 yds to red oil drum. Canon G1X at 28mm, ISO 1600 f/5.6 at 1/2 sec exposure.

(Edited XP-G2 numbers, I had 525 down when it made 557)

That is a great comparison Dale! Thanks for sharing..

Nice mouse over, what were the original tints you were using? Did you use the gasoline method for the dedome? Love how the tints came out in the pic.

Edit, I see you used 1D tint

7.2A and only 565KCD?

My TK 61 with only dedome is doing ~ 300kcd - 3A. Should i get to at least 500kcd - 5.7/5.8A?

The XP-G2 is an S2 2B, gas de-domed. The XM-L2 is a U2 1D heat de-domed. In each case the tint stayed quite nice.

dazed1, I'm a bit perplexed as well. I'm using the HX1175b1 driver to get that 7.2A (well, both numbers but with different resistors) I have a 40mm disc of copper .9mm thick under the 20mm Noctigon. Heat dispersal is near immediate into the head, you feel it and know it's working properly.

I do believe my reflector is off somehow. It seemed warped or something and would not center which is what led me to cut the entire bottom out of it to fit over a 20mm Noctigon. Check out this pic, the base of the reflector is clear...not touching anything at all. The reflector is held into the head by the lens and bezel and is snug. So why the obvious distortion to the left?

Hi

Its reflector seems out of focus in height…

How can you possibly tell the height positioning looking at a picture taken straight down on the emitter?

The focus is perfect at that height. 557.5Kcd with this XP-G2 you see.

It was adjusted actively, tuning in each direction past this point then back to what works best for this light. Meaning, while it was on, shining at a target 35 yards away, the height was adjusted to optimize the hot spot. And right where you see it is what works best. The chrome looking surface of the flat at the bottom of the reflector is approx 1mm above the star. The donut hole in the beam merges at about 1M when shining it at a wall.

I think, because he cannot see the yellow phosphor in the reflected image… bit it is just a guess on what he is looking at.

So I said “seems” :wink: If you corrected the focus is ok…just wanted to collaborate.

I thought it should look like that :

If I’d pulled the camera back to about 3’, or the focus point, it would look similar to that.

That picture was taken to show the reflector cut out to accept the 20mm star. And of course, is actually the Fenix TK61 that this thread is about. :wink:

Taken from almost 7’ above the light…

Take a picture at that distance, and it looks very similar to your photo sorry! :frowning:

Of course, is thread of Fenix TK61 :~

See how that warp in the outer edge of the lens remains consistent? I believe this is what is keeping this light from being far up into the 600Kcd territory.

Also notice how the reflector has an appearance like it’s Orange Peel? This is a smooth reflector. These are reasons why I dislike plastic reflectors.

I also think that it should be within that territory…. I think the poor finish of this reflector is the cause, you did something? try to clean it? does not look like std TK61 reflectors

No, I didn’t do anything to it, other than cut the bottom out.

Ordinarily if an aluminum reflector has ripples or lines in it I’ll hand polish it out. I’ve had great success with this. Again though, can’t do that with a plastic reflector. Beats me. I’m planning to search for a good reflector that will fit in here and see if I can get a better result.

Anybody know where a TK61 reflector can be found? Or one from another light that will fit this one?

Hi guys, did anyone measure,

Stock TK61, dedome only, current bump + dedome, how much cd does it increase with current, is it linear or at least close to it? based on this, it should be 1700 lumens or lets say 1650, does this means around 60% throw increase? thanks.