Utorch UT01 Mod BLF A6 Driver With NarsilMQ8 1500 lumen's

I didn’t really like the UI of the UT01 but it was ok. I had already modded a Klarus Mi7 using practically the same setup. So I imagined this light would benefit from the same mod.
I took the bezel off and removed the reflector and lens.

It also had this little plastic protector on top of the led.

I unsoldered the led wires and took the MCPCB out.

I wanted a better MCPCB in there to run the fet driver so I started with a 16mm Noctigon.

The Noctigon was to thick and the diameter in the UT01 head was smaller than 16mm. Took the belt sander to it to lessen the diameter and the Noctigon board was way thicker, so I sanded on the bottom of MCPCB until it was about the same thickness as the original board.

Then I reflowed a XP-L V6 3D on the Noctigon. I didn’t much like the tint of the NW that was in there, to yellow for my liking.
I pushed the driver out the bottom from the led wire holes from the top end.

It came out pretty easy just taking my time and not rushing it with to much force.

Then I set in making a new driver with the BLF A6 A17DD-L FET+1 from BG. This is the X6 driver but they are the same except the X6 has the attiny 25 and a bleed resistor running from ground to the led red output wire.

Then I hot aired the attiny13a off the board and bent the legs in on a attiny85. And reflowed that where the attiny13a use to set. Loaded up NarsilMQ8 to the attiny85.
I had a hard time figuring out how I was going to mount the switch at just the right height to contact the switch. I measured the original placement and measured down in the head. What I found was that the original switch didn’t set as far back in the head as it probably should have to make good positive contact with the rubber plunger. So I had some old driver boards laying around, started measuring them and two pieces of a thick board I had would be just about the perfect height for the switch. I cut two pieces off with my proxxon rotary tool. Cleaned them up from all the solder and filed them a little to true them up. Epoxied the first board down right on top of the FET as this was about the only place I could find that everything was in the clear. Epoxied the second board to the first, turned the board so that the copper trace was on top so I could solder the switch ground legs to it. Soldered the switch on in about the same placement as the original from the outside ring. I then soldered a thick copper wire to the 3 ground legs of the FET and bent the other end to touch the top board and one switch leg. This gave the top board copper trace ground witch gave the bottom legs of the switch ground when I soldered the switch to the copper trace. It also helps support the switch and boards more than just epoxy.

Then I soldered on a wire from the top switch leg to pin#2 of the attiny85.

All wired up and ready to go, well almost. When I had modified my DQG tiny 4th with a triple xpl running the same board, I had a problem with the BLF A6 board trying to move around inside the head when you screwed the tube on. The switch would move because it’s connected to the board and it would quite working. I came up with a solution because I knew this UT01 would have the same problem unless I glued the driver in. But I didn’t want to do that because it’s a pain to get back out if there’s ever a problem.
I took a piece of regular old house wiring, I believe it was 14/2. Cut a very small piece off and cleaned it up a laid the flux to it. It had to be placed on the board at a 90 degree angle to the switch. In the head where the driver sets there are two channels that are cut right below the led wire holes at 90 degrees to the rubber plunger.

This was the perfect place to make a lock so the driver could not spin once installed. I soldered the wire right to the amc7135 ground leg flush with the outside rim of the board. Cleaned up any stray solder for a smooth install.

The fitment was right on put everything back in it’s place and solder up the led. Put the plastic protector back on and lens and bezel. Inserted a Efest 14500 700mah and Bam! 2 Flashes and NarsilM is up and running. Draws 4 amps measured at the tail. Maybe around 1500 lumens out the front of a Utorch UT01. :smiley: :smiley: :smiley:
Moonlight level #1


Nice project. You used the original UT01 switch, right? Before doing this mod, did your UT01 have the switch problem when using a 14500 where it won’t turn back on after shutting it off without breaking the circuit by unscrewing the tailcap or head? If it did have this problem, and you’re using the original switch, did the switch problem go away after doing the mod?

Very nice mod and good to see it working. I failed miserably trying to get the Attiny 85 with Narsil running on the A6 driver.

I used this switch from digikey. https://www.digikey.com/product-detail/en/e-switch/TL3365AF180QG/EG5384CT-ND/5964420
My original driver is still fully intact.
I had no issue with the original driver.
I did notice however that cleaning both ends of the tube and giving it a good spin when ready to use gave no problems. If you slowly, lightly turn the tube or tail cap until it stops, it seems that sometimes that doesn’t give a good contact. The light might flicker, or doesn’t want to turn on unless bumped or tightened again. I try to give it a quick spin until it stops now, or a little more torque. Even after the mod, if I don’t give it a firm spin to lock it will have the same problems as original. There maybe some other problem with some of these lights besides this, but that’s all I observed with my 2.

What problem were you having, maybe I can help. Did you use NarsilMQ8?
The driver is very nice for the price but once you add the attiny85 and NarsilM its super nice for single cell lights.

this is just crazy! I am so envious of you guys that can do this kind of stuff! So, I am supposed to go back and use my simple UT01 knowing that you have this custom job that puts out all those lumens and has an incredible UI??? Is that the same UI that is on the Q8?

If you told me you had $100 into it I wouldn’t feel so badly!

I’ve been searching for something like this for months. Thanks so much for posting this!

Dude, this is simply great!! I am one of those that wish to have skills and tools and knowledge to do something alike!
Great work, really!!! :THUMBS-UP:
Wish I could make this to my Manker E11! It would turn my favourite light ever!!!

I have a Klarus Mi7 ti that has the same A6 NarsilM attiny85 heart transplant. I prefer the UT01. I just like the looks and feel of it better, a great UI and generous output that handles the heat better than the Titanium Mi7. Its my favorite small light at the moment. Really like the loosen tail to lock out and NarsilM also has a lock out, I don’t want a accidental turn on in my pocket. Its a nice host but Narsil in such a small EDC light puts it over the top for me.
Thanks for your comments.

It is the same UI as the Q8 two channel, NarsilMQ8.hex
I got about a 150.00 in the light. :frowning:
Just kidding, Didn’t want to make you feel bad.
Light and all with new led around $27 and several hours of tedious work.
Thanks for your comments.

I love my UT01 and since it failed recently I am thinking in doing this mod to return it back to the rotation. I think I understand the hole process but I am new to flashlight modding and I have some silly questions. I am a bit worried about the switch fixture, specifically the heat the FET will produce and the epoxy. Is this something to worry about? How hot could the FET go at max output levels? Did you use any thermal paste?

Great post! Thank you very much for sharing this mod!

This is a great mod!

Where can I get one ?

Only thermal paste used was under he MCPCB. This mod only draws a little over 4 amps from the battery. The light does get hot (wouldn’t fry a egg) but not nearly as hot as the D4 or my DGQ 4th running a triple that draws 14 amps from a Samsung 30Q. The UT01 copes with the heat pretty well for a small light. 4 amps out of this FET driver is nothing compared to 14 with the DGQ using the same driver setup. What limits the current in this light is the smaller battery (more voltage sag) and the smaller wires and the higher vf of the xp-l. With a xp-l2 it probably will draw quite a bit more current.
The Efest 650mah (purple) is one of the better batteries you can use to keep voltage sag to a minimum in a 14500 size. Even though this is a the top of the chart for a 14500 it doesn’t hold a candle to what a good 18650 will do. You can compare battery sag for different current loads here on this very informative site. https://lygte-info.dk/review/batteries2012/CommonSmallcomparator.php
As for the switch, its soldered to the top added board and to the A6 board FET ground to the ground switch leg to give it some more rigidness. Each side of the switch has to isolated from each other, the other side of the switch leg goes to pin2 of the attiny85. This can be done on the board underneath the switch. This piece of driver board I used is the outside rim where the ground contact would be. So it has a copper layer under the outside ring, you can see the black center section behind the switch and the gold section under the front of the switch in the pic above. Just cut the copper layer in half with a knife or dremel tool and mount the switch between the cut, now you have two sides to solder to and there isolated from each other. The epoxy maybe the week link but the switch has one leg solder directly to the FET ground and my experiences with epoxy has been when you use it between to flat surfaces and applying pressure keeping the epoxy to a minimum thickness it creates a suction that’s pretty hard to break usually. I don’t know how much heat the FET is making but I wouldn’t think its a lot with 4 amps. :smiley:
I have found better and cheaper $) switches to use that are made of tin on the outside case that make solder directly to the board a breeze, no need to cut the copper layer.
These are my favorites and these work well too.
To make a driver swap easier in the UT01, I would just use a mtn electronics 17mm FET+7135 driver loaded with a electronic switch firmware (the D4 V2 ramping being similar to NarsilM). or you could use a regulated board at 3 amps.
Then you would just need to mount the switch and solder the switch legs to the appropriate locations and your done.
Happy modding :beer:

Good thing nowadays we have the GT Micro driver to fit in the Utorch UT01 / Manker E11 / Lumintop EDC05 :P (physically identical in size and shape to the original/s in these lights)

Did my EDC05 with the GT Micro driver few days ago and it was a much less painful process than all the work that has been put in here (probably less satisfactory as well, but.. )

It was still painful to press fit the bezel and the switch without the necessary tools, but few little scuffs here'n there later, it all came into place :)

Very happy with my unbranded EDC05 running Narsil (although I should've enlarged the switch hole as it is with the Micro, so the indicator LED would actually be visible, as it's located underside the switch's PCB.. )

Got the driver configured with the indicator LED Off for now and not sure if I won't leave it at that since a 14500 cell only holds so much juice inside it anyways..

Still waiting for Gearbest to deliver my UT01 (because it has a screw in bezel, thus it'll result in a much cleaner job) for almost a month now and the order barely got shipped on yesterday.. :/

I guess I'll buy another GT Micro driver meanwhile. I'm happy with the EDC05 still, but i really can't stand the press fit bezel and the scuffs that had to result from me pressing it in..

I also haven't had any kind of grinder to get the copper MCPCB slimmer for this host (in fact this would apply to all of these 3 hosts equally true) thus the bezel still got ~.2mm a bit over being flush with the head.

Even though I've used a slimmer o-ring for the glass lens, the reflector and the body had slight grooves for it, thus slim to no difference had resulted from it (at least the pressure on the bezel was bit lower though)

With the Utorch UT01 / Manker E11 hosts this would still be mitigated to a degree because of the screw in bezels - just screw the bezel ~1 turn less, but it's still going to be fit and not going anywhere.

Hold up. I can buy a GT Micro driver and drop it into my UT01? Details on the installation and how to buy this driver please…

But who sells the driver ?

Yes, the GT Micro driver it's pretty much a drop in 99%compatible (I shave 1% off because of the indicator LED not ideally positioned - or at least not without enlarging the switch hole on the EDC05 that is.. Maybe it's not the case for the other two hosts)

Myself, I've bought the EDC05 "host" (as in I requested specifically to be not assembled but in all pieces) and the GT Micro driver from the AliExpress official Lumintop store. I've just had a chat with the seller that I've broke my few hours old EDC05 light trying to mod it and I'd like to buy one with the bezel off and maybe even the switch booth as well. Turns out the seller just took a EDC05 from the assembly line and sent it in pieces, packed in nice bags, even the emitter cut off from the reel and not soldered on the original aluminum MCPCB and the glass in the protection electrostatic foil. As a nice touch and addition, the seller also included the GT Micro (I assume) copper MCPCB that I've overlooked to ask for (because of the higher power output of the GT Micro's driver.

I'll edit in a link later on.


The link seller sent me with the amount of payment for the items that I've requested: https://www.aliexpress.com/item/32793243604.html?spm=a2g0s.9042311.0.0.73434c4d6fFbV3

That is after I've had a chat with the seller about what I want in detail. I can also see that my feedback has got approved - thus you can see the pics of what has been bought / sent / received :)



Basically, what has been sent:


Demo.. (mind the professionalism behind the video making tho.. )

Does that gt micro mcpcb fit the ut01 too, can’t remember what’s in it now