Review: YEZL T9 "Flood to Throw" Zooming XML Light

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Fritz t. Cat
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An other reason to change the lens is that the one that came in it is spherical or nearly so. The outside is more focusing than the center. This results in a larger spot outside the main one at full throw, which is not bad. It probably works better than a perfect aspheric at full flood. But partially zoomed it makes the outer part of the spot brighter than the center, which is bad.
The one I got from AliExpress is less focusing at the edge, which is likely a reasonable engineering compromise. It makes a larger spot or halo around the main spot but the main spot is uniform. The main spot led image is about the same size as that of the UF-T20, so the center has the same focal length, even though it has no flange so that the active part is wider.
Added: I put the $27 AliExpress lens on it with old fashioned Duco Cement. Seems to work great. Not an ideal sharp focus aspheric, but it works well. The whole 38 mm. width transmits light, and, depending on the zoom, most of it contributes to the spot. There is a brighter edge on the spot at some zooms.
This is my best light now.

Flashlight designers should look at lighthouses and pottery.
这些谁设计的手电筒应该看灯塔,以及在陶器。

Fritz t. Cat
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yavi wrote:

cd520 wrote:

The switch in mine began to fail and I pretty much destroyed the tailcap getting the switch out. It was some really crappy designed pressed/locked in switch. It was the first light I ever had with this type of switch.

To dissasemble it, the best way is making two small holes on the plastic ring that retains the switch, and then unscrewing it.


The switches of the new ones appear to be held in by aluminum disks that form the negative contact, but I will try drilling holes and unscrewing.
I drilled two holes and applied quite a bit of torque with needle nose pliers and no movement. It now appears that the whole tail cap is a solid piece of aluminum with only the switch boot and a small hole in the center that the spring comes out of, and the anodizing cut away where it contacts the end of the battery tube.
Maybe there is something better than pink duct tape to put on the threads to make it lock out to be a twisty. The intermittent switch with the Q-light driver only serves to change modes.

Flashlight designers should look at lighthouses and pottery.
这些谁设计的手电筒应该看灯塔,以及在陶器。

Fritz t. Cat
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My second Yezl’s driver went out when I put the cell in backward. Apparently no reverse voltage protection. I replaced it with a Q-Light set for the moonlight group. I de-domed the led while it was apart. I kept the original led, rather than trying my first de-dome on a fancy new one. It draws 2 A with a good 3.8 V cell and out throws the other one.

The $27 lens came out easily after leaving a little acetone around the lens to soften the Duco Cement while it tail stood for an hour.

Flashlight designers should look at lighthouses and pottery.
这些谁设计的手电筒应该看灯塔,以及在陶器。

Fritz t. Cat
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27$ lens and de-domed original XM-L on left, UniqueFire lens and warm XM-L2 on right.
1.6 A on the de-domed XM-L and 1.2 A on the warm XM-L2.

The former draws 3.05 A on the cell charged to 4.2 V.

Flashlight designers should look at lighthouses and pottery.
这些谁设计的手电筒应该看灯塔,以及在陶器。

Fritz t. Cat
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I got the switch out of one of them.

It is 9.4 mm. in diameter and is forced in place from the outside. A plastic ring is forced in also from the outside to retain the boot.
So I need a 9.4 mm. diameter switch that turns off, not just momentarily interrupts. Or a tail cap with an on/off switch.

Flashlight designers should look at lighthouses and pottery.
这些谁设计的手电筒应该看灯塔,以及在陶器。

Fritz t. Cat
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I found that the switch from a Black Cat fits and works. I have not been able to buy switches separately that fit, so I ordered two more Black Cats, one from Fasttech for $8.50 https://www.fasttech.com/p/1387212, and one from KaiD for $8.00 http://www.kaidomain.com/Product/Details.S008793. The FT one is to replace the one I just cannibalized. Not all the Black Cats from KD work out of the box, but they are 50 cents cheaper and the switch should work in the other Yezl. $8 doesn’t seem out of line to replace the switch in a light that I consider to be a bargain at $17.10 and that has a $27 lens on it, plus an XM-L2 and a Qlite. Nut Lights and Warsun X65s out throw them for way less cost, but they are almost as ugly as Unique Fire T20s.
I don’t mind twisties, but the day glow imitation duct tape gets loose after a while.

Flashlight designers should look at lighthouses and pottery.
这些谁设计的手电筒应该看灯塔,以及在陶器。

Fritz t. Cat
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In one, I have a Black Cat switch, an XM-L2, a Qlite driver and a lens from a UniqueFire UF-T20.
In the other one, I have the $27 lens that is so big it has to be glued in. I now put an XP-L High Intensity LED (“Cree XP-L HI U6-5A 380LM 4000-4500K LED Emitter”) and a BLF A6 driver from Banggood in it. http://www.banggood.com/BLF-A6-A17DD-L-FET1-2_8-4_35v-74-Modes-Flashligh.... It is almost, but not quite, as bright now as my CNQ with a Nichia 219C. It out-throws it though. Fasttech is out of Black Cats, and the KD one has not come yet, but, with the 3 ma. moonlight mode of the BLF A6, I can use it with just the intermittent off of the original switch, as long as I don’t store it for weeks with the battery in it. Or the battery test / beacon mode has even less battery drain.

Left to right: Yezl with UF-T20 lens, Yezl with big lens, CNQ with Ahorton lens

Added: The Black Cat came. I had to glue the switch in, as it is too small for a press fit. I destroyed the rubber boot when taking the plastic ring that holds it out, because I didn’t know that the ring is screwed in, not force fitted. This time the ring is in tact, but I can’t find a boot that fits.

Flashlight designers should look at lighthouses and pottery.
这些谁设计的手电筒应该看灯塔,以及在陶器。

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