My Ut01 is scheduled to arrive this Monday or Tuesday. Wonder what my fate holds in store for me concerning the flashlight. Work or no work is the question. My Lumintop Edc05 seems to be lost in transport. No update info since December 25, 2017.
I have the same problem as Rock with the one I received recently.
I have 4x UT01 now. Two work perfectly. Two have the common issue with requiring a power-cycling after being turned on once with unprotected 14500.
I’ve observed that battery length and perhaps clearance in the head seems to be an important contributor. My hypothesis is that the spatial tolerances in the head are such that with too much pressure components pressing against things they shouldn’t. This leads to cracks in solder, which leads to a open or higher resistance in some key circuit. The excess pressure probably comes from trying a long cell, like a protected 14500.
Swapping in a shorter cell, relieves the strain and allows the cracked joint to make contact again. Putting in a longer cell, like an un-protected 14500 opens up the gap again.
The glue holding the driver board breaking loose could also trigger the problem because it allows the driver assembly to be pressed further/harder into the head.
Replacing the switch itself may not actually be what solves the problem. Rather, the process of replacing the switch may close the cracked joint again. If the replacement switch is slightly smaller, that may also help by reducing the pressure that causes the break in the first place, and opens it under too much pressure.
Rotating the driver board slightly to center the switch may move the switch out of the way of something in the head cavity it interacts with and/or it may give the driver assembly slightly more room because of lack of uniformity in the depth of the adhesive between the top of the driver and the ledge in the head cavity it presses against.
My earlier observations that battery voltage seemed to be a contributing factor may actually be explained by the fact that my NiMH cells are slightly shorter than the alkaline I tried, which are slightly shorter than the flat-top LiIon 14550 I tried.
When I get a chance, I’m going to see if putting something between driver and the ledge of the head cavity helps.
Just received my Ut01. Seemed to be DOA. No matter what I did it would not work. Used freshly charged Eneloops. Suddenly started working with only high,low. Then fizzed out. Realized head was a bit loose. Tightened both flashlight head and tail cap. No works just fine. Has all modes working.
Looks like I got lucky. Mine arrived yesterday and works flawlessly. Using Efest 700 (red) batts.
My EDC05 arrived today. Well built and very nice warm tint. It is a good 4mm longer than the Utorch ut01. Protected 14500's fit with lots of extra room. No longer exact copy of the Utorch. Solder joints much better also than the Utorch.
I have the same problem with my UT01
I’ve tried it with regular short alkalines, with Eneloops, and with unprotected 14500. All lead to the same result - you have to cut power to the driver via loosening the tailcap before it will power again. I also took a quick look at the little spike jobbies sticking out from the driver, and they aren’t long enough to contact anything on my cells. The driver seems flawed. As an aside, this driver also will not go into program mode, so maybe they were forced to remove the program mode and broke some other aspect along the way (?). Keep me posted, guys, if you unravel the mystery any further. Thanks.
Welp.
Update: Now it will only turn on if I'm using regular alkaline AAs. The length of those seems to be identical to the Efest 700mah (red) 14500 I was using before. What gives? It's not the Efest batts as I tried three of them fully charged and none would get the UT01 to turn on.
So strange.
I agree completely with eas. I ended up using a circle of thin silver solder in the tail caps to give a bit more length.
I suspect that many of these issues start from the tubes being too short, and the initial battery install causing permanent crush-force damage to the driver.
Every one of my four had the anodized edge of the tail cap making contact, or almost making contact, with the anodized lip on the tube when I received them. Only a hard tightening would result in contact of the conducting surfaces. I added length and the problems disappeared.
Have any photos of how you did it? Where in the tailcaps?
When i tried a protected 14500 in the Utorch Ut01 it was dead. Nothing. I traded the body and tail cap of my new Lumintop EDC05 and the Ut01 worked fine. Has to be an issue of length. The body of the UT01 is just to short to work correctly.
(Reply to Mtonne here, but my post ended up in the wrong place)
I don’t know how to post pics here, but it goes right up inside against the inner circumference of the cap and up against the outside edge of the switch plate. I used 1.6 mm rosin core solder (.062”) and its just right. Not too stiff and not too soft. Adds just enough length. Wrap a piece around an AA cell, and you’ll be pretty close in size.
Trim to length with your nail clippers.
It should end up the same size as the shiny end of the tube, so it squeezes between the end of the tube and the switch plate - hence increasing the inner length of the tube by 1.6 mm. Wiggle it in there with tweezers.
Other materials will no doubt work as well, but I find the piece of solder is just the right softness to form easily into a circle and sort of squeeze into place and stay there. (Just don’t use acid core solder, that’ll mess things up for sure).
Thanks so much for the explanation. Makes way more sense now. I've got rosin core solder so I'm going to try it out now.
I too believe this may be causing some of the issues. My UT01 would not work with any of the alkaline batteries I had on hand, the battery tube is too short and the spring bottoms out before the tail cap makes contact with the end of the tube.
The unprotected Sanyo 14500 worded well. Tried the alkaline’s and just jumped from the rear of the battery to the end of the tube and they all worked.
As others have mentioned, a small diameter wire formed into a circle that fits around the outside edge of the spring and the tail cap will fix the problem, for my light anyway.
Worked like a charm. 60 seconds of work. You, sir, are a gentleman and a scholar.
Received mine recently (3D) finally had a few minutes to play with it. Installed a regular Alkaline primary cell and it worked great, real nice tint, switch works fine and all modes are working, I switched many times through all 4 levels and back to off, plus 2 clicks for hidden strobes with no problems.
The memory mode (long press from off) only memorizes L-M-H modes, it does not memorize Moonlight, I guess you wouldn’t need that because a single click always enters moonlight anyway.
I haven’t tried a protected 14500 because I didn’t want to crush the driver, don’t have any shorter unprotected right now. I also have some NIMH I will check their length and try later. My 14500 protected 750mAh AW is only slight longer than the Alkaline, will try that one later after I do a paper clip mod in the tailcap.
I also didn’t try programming the levels yet.
The last good AA/14500 light I bought was an Olight S15, but it was only available in CW and its greenish blue tint is pretty ugly. This UT01 NW tint is far better for my liking. The Olight has a much larger reflector and a tighter hot spot, the UT01 in comparison is thinner, shorter and more compact. I’m really liking this light so far!
OK I tried the programming, there’s nothing in the user manual about programmable output levels but I got the instructions from the review thread: Review : Utorch UT01 Flashlight (XP-L V6 / AA & 14500 / e-switch)
The reprogramming function appears to be working but it’s kind of confusing, it went through the sequences as described in the review but there were only 3 programmable modes instead of 4, apparently High is not programmable?
It says in the review “Light has programmable output levels for every mode” but after I set levels for 3 lower modes it just goes to high and is no longer auto-ramping, then I have to single click to get to strobe (to turn off in strobe as described in the review instructions). I have to spend some more time with the programming.
In programming there are 3 levels to chose from, anyone know what the factory default levels were?
Maybe they don’t want people messing with that since nothing in the manual about it?
Mine was able to program all 4
How recently did you order yours? (I ordered mine on Dec. 19th)