Group Buy for the GearBest Ultrafire F13 - Closed?

Thanks. I’ll give that a try when I have a chance. I had good results on a different light (this one: https://www.fasttech.com/products/1700404) with a similar mod, so it should be a good one.

This F13 is turning out to be a heck of a deal, huh, thanks to O-L and gearbest!

Yes, you can’t see the traces, but that long row of resistors, it is between the output pin of the 8 pin FET and the 26650 pad, current limiting resistors, the pad on the other side completely bypasses the resistor bank you get the FULL output that the FET can produce. If you really want better power to the emitter, then get thicker gauge wire as well.

APM9435 datasheet
[PDF](javascript:openreq(‘ANPEC Electronics Corporation 126018, 1 datasheet pdf’))

Pins 5,6,7,8 are all the drain (tied together)

P.S. When you move that wire put some heat sink compound under your star…mine came with none, it WILL get hot when you move that wire…count on it :slight_smile:

WarHawk-AVG,

Ahh. So by moving the + lead to the other pad, and bypassing that bank of resistors, it’s basically really direct-driver + the Rds for the FET, on high mode?

And yes, I was thinking that I’d go to heavier leads while I was at it, and thanks for the reminder re. adding some thermal compound under the star.

EDIT: BTW, I don’t know if it’s just with the light I have, but I’ve noticed that there’s a bit of a doughnut hole in the center of the beam when it’s up close.

Looking at the reflector and centering ring, it seems like the centering ring might be a bit too thick, so the top edge of the centering ring is almost at the same height as the top of the XM-L dome. Has anyone tried tweaking the center ring piece, or maybe tried one of the butterfly-type insulators instead, or maybe even just some kapton tape instead of the centering ring?

Some have replaced that thick centering ring with a thinner centering ring/insulating gasket

It’s DD either way. Nothing but the overall resistance of the light (including the driver) limits the current. Those resistors are there to reduce current, I simply wanted to point out that it’s DD with or without them. They don’t actually regulate the current, just reduce it.

desides that solution,i am talking if you want even more ,if there is a way to do it with those resistors.

Has anyone else notice the beam is a little weird.

The hot spot is a perfect circle, odd for a LED with a square die. And the hot spot is larger than other XM-L lights I have (both bigger and smaller SMO reflectors).

Anyhow I removed the reflector and the white centring ring. The reflector then drops a lot further over the LED. But sadly this doesn’t improve the focusing, it makes for a very defused hot spot. You actually need to elevate the reflector a bit to get the best focus, but without the white centring ring the focus is still poor, not all that tight and ringy. Makes me wonder if this lens isn’t really optimised for an XM-L size emitter and output angle.

With the white ring back in place it returns to what on a white wall looks like a good hot spot, very round, very well defined and very large. But it must be an effect of the white plastic ring causing this. Shine another XM-L light next to it and you’ll see a slightly less round smaller hot spot but much more intense (even one pulling less amps).

This translates outside, the throw on my F13 is quite poor. My Convoy M1 OP reflector easily out throws it by quite a margin.

Not sure if any of this makes any sense of not. Probably easier to see in person than words.

No, you are making sense. I did much the same experiment last night, by removing the centering ring and putting tape on the end of the reflector instead to insulate it. Just as a test, because without the centering ring, it was hard to get the reflector to center (it moved when screwing in the head). That got rid of the doughnut at close range, but the beam had lots of rings.

I noticed that the reflector has a kind of large flat area around where the emitter is, compared to other XM-L lights, which looks a little strange?

Of course, 3.7Volts anyway, with which these ‘drivers’ can’t do anything useful.
You will smoke it…

I moved the + lead to the other pad on the driver, and tailcap increased:

Battery 1: 1.26 amps => 1.7 amps

Battery 2: 1.69 amps => 2.1 amps

That was just with moving the lead. I didn’t change to different wires, because I wanted to be able to see the effect of just the one change.

FYI, the insulation on the factory wires doesn’t seem very heat resistant, so be care when soldering them.

wow, that is quite the change. I wonder how much a difference it would be if you add 18g wiring.

I tried without the centering last night, too. I was surprised how much the reflector could drop and disappointed with the beam, but then I thought it might be very helpful with a de-domed emitter. Everyone complains about not being able to get the reflector low enough after de-doming, maybe this will turn out to be a plus.

I don’t know yet, as I haven’t tried that. A bit of a time soldering still (eye surgery a couple of months ago), so I’m trying to take things easy, but I did just do the solder wick on the tailcap, and after that:

Battery 1: 1.26 amps => 1.7 amps => 2.1 amps

Battery 2: 1.69 amps => 2.1 amps => 2.6 amps

FYI, Battery 1 is an old laptop pull (dark blue wrap) and Battery 2 is a “20R” battery.

Also, I’m just using the normal meter leads, so the tailcap current is probably higher, right?

I know you all normally recommend doing the solder wick on the springs, but this is the 1st time I did it, and I’m kind of amazed at the difference it made :)!

What did you do to insulate the reflector (prevent it from shorting)? Did you put tape on the end?

I keep thinking that an MT-G2 would fit nicely in that reflector opening, but don’t have an extra one at hand…

It was just a quick look to see what difference removing the centering ring would do so I didn't insulate it. Not a problem with the small reflector and 20mm star. The opening is only 7mm, an MT-G2 needs 9mm just for the dome.

I was thinking that the F13 reflector has that rather large flat area around the emitter area, and that the opening could be opened up a few mm to fit an MT-G2…

Not too difficult to get 9mm for the dome, might be tricky if you want to set down over the entire square package.

I have another (different) light that i put an MT-G2 into, where the reflector opening just barely fit the dome (the entire dome, but not the die), and that has a very nice beam… no rings, etc., so I think that the opening wouldn’t have to be large enough for the die, just the dome. Unfortunately, as I said, I don’t have a spare MT-G2 at this time to try it though…

Let’s keep our terms straight. You two are referring to the ‘package’. The ‘die’ is something else.

Sorry, you’re right :)…