MascaratumB’s entry – Old Lumens Contest 2022 – Modified Light Category – “The Bistrix Mule” (started and finished :p)

So, this is my “flash” entry in the BLF OL Contest of 2022!

I‘ve thought about entering for a while, but I had no project in mind, until recently. So, I made up my mind and decided I would enter in the “Modified Light” category! I hope the judges accept my entry in this category :wink:

First of all, a word to all the contestants, wishing good work, good luck and the appreciation for what they are doing! A word of appreciation to the organizer(s), sponsors and judges that make this contest possible, honouring Justin’s memory once again! :blush:

For me, it is nice to enter once again, this year in a much simpler way! :THUMBS-UP:

So, to let you know what I’ve done, below I will detail:

- The modification done

- The materials used

  • The tools used

Despite this is a “flash” entry, started and finished once again in the same day, please ask your questions if you want to and I will try to reply in the best possible way :))


The Modification & The Materials

You probably know the Fenix E12 V2.0 flashlight, right? I believe some of you were more familiar with the old version of this flashlight, but I never had one, so I used the most recent version.

This flashlight was sent to me for review (upcoming on BLF, but with video published on YT here: Review - Fenix E12 V2.0 - YouTube ), and I always wanted one to try to mod it.

The Fenix E12 V2.0 is one of the smallest AA flashlights in the market, it is perfect to gift one to someone not used to flashlights, but…I needed something more. :sunglasses:
Originally it has a Cool White emitter (MATCH CA18), a driver that only takes AA batteries (1.2V or 1.5V), no memory, and puts out 160 lumens. Some of the things I liked, but I felt that this little host could handle some more :smiling_imp:

When I started thinking about the mod there was a major issue I had: the driver. The Fenix E12 V2.0 takes 15mm driver, so using a 17mm driver (that would give me with much more UI options) was a no go. As currently there are no producers of 15mm drivers with UIs I like, I had to pick one from another flashlight I modded 2 years ago.

So I picked a 15mm driver with Bistro HD OTSM, made by Lexel, that I was using in the Lumintop Tool AA V2.0. It was already “shaved” on the sides to fit the Tool AA pill, but it could be used in the Fenix E12.

And given that I will use Bistro , and given that I always give names to my OL Contest projects, this one will be called The Bistrix Mule, a mix of Bistro and Fenix :smiley: :partying_face: You’ll see the “mule” part right away :wink:

By now you already know the driver I used, but you don’t know the LEDs. When I bought my Wurkkos TS10, I ordered some triple MCPCBs with CSP 4000K LEDs (Lumileds Chip Scale Package LatticePower CSP2323). And it was one of those MCPCBs that I used for this mod. Without the Aux leds, of course :stuck_out_tongue:

Well, but there are always issues when we want to use fancy things in simple lights, right? That’s the case here… To use those MCPCBs, we need special triple TIR optics, that I don’t have! Also, these MCPCBs are larger than the original of the Fenix (16,66mm vs 15,81mm) and cannot be trimmed down adequately to fit the head.

So…I needed to figure out another option. And that option would be to make a “mule” flashlight.
How? By elevating the MCPCB to near the lens and not using TIR, or reflector.

And this is how it was done!


- first of all, I dismantled the light:

  • by using a lighter, a leather belt and some pressure pliers I forced the rotation of the tailcap
  • by using a work knife, I managed to get the bezel out (press-fit)
  • by using the soldering iron, I unsoldered the MCPCB from the driver’s wires
  • by using a toothpick I press the driver (glued) out of the head

[all these processes were previous to the modding process, and were done some weeks ago!!!]

These are the original parts of the flashlight and some of its internals. In the final mod I didn’t use some of them: the thin transparent ring, the black o-ring, the MCPCB & LED, the driver, the optic!



- secondly, I studied what I could use to make my “The Bistrix Mule” project become reality, and for that I picked:

  • the 15mm driver w/ Bistro HD OTSM w/ 20AWG wires
  • the triple MCPCB w/ 4000K 90 CRI CSP LEDs
  • a sanded/filed copper DTP MCPCB
  • a copper spacer I ordered kiriba-ru some time ago for another project

Also, for the final version, I kept the some of the original pieces:
glass lens
tailcap w/ reverse clicky switch

Both the thin copper DTP MCPCB and the copper spacer were already filed before but I needed to file then down a bit more. Also I needed to drill a hole in both of them. For that I used my Parkside rotary tool with different drills, and also some files to enlarge the holes and to flatten these two pieces.

I also needed to drill a hole in the centre of the shelf of the Fenix head , so that the wires could pass through the middle (since the MCPCB has a hole in the middle as well). Same process, same tools as above.



  • third, with the holes drilled, it was time to start “mounting the cake”! Or the mule, in this case :stuck_out_tongue:

1) check if the driver fits and works! YES, all good! :+1:

2) screws get back into the head, start making the ”copper sandwish” and put it on the shelf! YES, all good! :+1:
I needed to be sure that the copper pieces were as flat as possible so that:
a) they could sit together between them (and the shelf)
b) they could make the proper space to – as I said above – “elevate” the MCPCB enough so that it could fit in the upper space of the head, where it had a larger sitting diameter

3) it is time to sit the MCPCB over the copper sandwish and check it everything is OK, if the driver wires pass well through the holes, if the spaces are OK to fit the bezel and lens, and it there is no oscilation! YES, all good! :+1:

4) time to solder the wires to reach the final stages of the modification, and try to lit it up! WELL, almost all good… :neutral_face: :cry:

This was the step when I started having some trouble. Using the 20AWG wires has a problem in this case, because they are thick and the silicone was protruding, which would cause me some issues fitting the bezel, lens and o-rings.

With the nail clippers, I trimmed a little bit the silicone to make it as flat as possible, but always being careful to avoid removing parts that could cause a short circuit. It worked well.

Still, it was still too tall to allow everything to fit well. This is when I needed to choose not to use the transparent o-ring between the lens and the bezel, nor the black o-ring that I would use as a spacer between the MPCPC and the lens.

I ended up using only the bezel and the lens which sits right on the wires, making it press fit (which is a liability in case the light falls, as it won’t have a cushion :zipper_mouth_face: )



  • fourth, with all the things in place, I put a battery and it was time to let it shine :smiley:

I didn’t mess with the driver configuration, so it is configured in the group 12:

I also think that this is what you can expect from a mule flashlight, a wide beam, without artifacts (well, maybe on the edges, eventually :p) :blush:

A small comparison with the Wurkkos TS10 (right):

And a line-up comparison with other AA/14500 Flashlights
Lumintop FW1AA > Lumintop FWAA > The Bistrix Mule > Wurkkos TS10 > DQG Slim Ti AA



  • fifth, I would like to make some reflection about this process:

1) it was not a complicated mod, nor a complicated build for this OL Contest, but I guess it keeps the modding spirit alive :wink:

2) It took me almost 3h30 making it since I needed to charge the rotary tool between drills since the batteries are not as good as they used to be :person_facepalming:

3) the most challenging part for me was to find the adequate spacers for the head, since I didn’t have any piece of copper, aluminium or brass that would fit the head exactly as I wanted or as it was needed, to keep the MCPCB in place. This was the part that put me to some major struggle but it ended up working well :wink:

4) I forgot to use thermal paste between the copper spacers and below the MCPCB :person_facepalming:

5) although the initial settings and specs of the Fenix were not the worst for an AA flashlight, I believe that it was improved, specially due to the possibility to configure the User Interface, and also because the tint and CRI improved :wink:

6) I wish I had a spare TIR optic for the triple CSP MCPCB because it would have been even funnier, although it would be also more complicated to fit it into the head.

7) from a modding and usability perspective, I know I could try to mod the tailswitch and make it a forward clicky switch, but I actually like the reverse option in this light (also, it keeps it smaller than lights with FC Switch)

8) the lens sitting over the wires is a liability in case the flashlight falls, as it won’t have a cushion and may break very easily :zipper_mouth_face:

9) I wish the H17F driver was made in 15mm single sided shape, since it would be perfect for this flashlight :heart_eyes:

10) although I could only make a single led flashlight, using the stock textured optic, it was more challenging to make this project :wink:

11) I like the imperfect final result of “The Bistrix Mule” :laughing:

:smiley: :student: :beer: 8):slight_smile: :innocent:

The Tools

Below are the tools and materials I used in the different stages of this mod!

The wood kitchen board, used when I was making the drills in the copper spacers :stuck_out_tongue:


Steel wool
Soldering wire
Soldering paste
Helping hands
Plastic Vice
Cutting pliers
Metal tweezers
Nail clippers

Metal tray
Soldering iron
Work knife
Latex gloves
Parkside “dremmel”/rotary tool

Thanks for reading :wink:

Great work mate, good to see i am not the only person still doing mods :smiley:

I used the same tools as you except i forgot my set mini files at home, they would have come in handy.

Looks good MascaratumB! I like how you resolved the issue with the 20 AWG wires. :+1:

Very clean work. Looks like a really nice light!

Ahah, thanks for looking EDSG :wink: I still love to do mods but my time and inspiration has been short, lately :weary: Still, I guess I wanted and needed to do this one to cheer me up and I like how it went :laughing:

I will take a look at the other threads, and will also check yours, to catch up with what you’ve been doing :wink:

Oh, the mini files are an essential when using these copper spacers, to open up some holes. I feel I need some new ones as these are starting break or to loose their grooves (they’re cheap ones :smiley: )

Thanks NeutralFan :wink:
Well, I am not completely happy with it, I should have use thinner wires to use some kind of o-ring to make a cushion there.
However, they ended up working well and the glass lens is held in place, pressed, due to the wires! I just hope it doesn’t fall and break :smiley:

Thanks :+1:

Thanks The Whispering Gallery :wink:
Well, I guess I was lucky this time normally my soldering works get messy as hell! Fortunately I managed to make them cleaner now :wink:

I would like to add some more photos, showing how the flashlight behaves outdoor :wink:

And some fancy photos, of course!

I would also like to add that I like the 4000K tint very much in this flashlight :wink:
I am sure I would also be pleased with th 5800K, like I am in the TS10, but “The Bistrix Mule” with the 4000K is really great :wink:

The Bistrix Mule (left) vs Wurkkos TS10 (right)

And some fancyness :stuck_out_tongue:

Thanks for reading :+1: :beer:

Very nice. I like mules and I like 4000 K. :+1:

Thanks MtnDon :wink:
4000K (ex: Luxeon V or Luxeon V2) is probably one of my most K in flashlights, and these CSP leds are great in that temperature! Specially being a mule flashlight, that has no shifts or artifacts :wink:

And I also like mules in 4000K :wink: :sunglasses:

>>>>>>>>>>>>>6500K >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> 5000K >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>4000K :smiley:

Great big belly chuckles! That was the laugh I’ve been looking for all day! :slight_smile:

Nice job on the project…always enjoy your photo essays and beam shots, great work.

Ahahah, c’mon, it’s me, I would do something like this just for the sake of wording confusion :wink:
Glad it gave you the chuckle :wink:

And thanks for your words concerning the mod/photos, Correllux :wink:

:+1: :beer:

I made a mistake on the name of the LEDs. Just noticed they are LatticePower CSP2323 LEDs, as seen in review of the Wurkkos TS10 . Initially I said they were Lumileds Lumileds Chip Scale Package.

Corretion done and apology for the mistake :+1:

Nice little flashlight with a funny name, MascaratumB. Great that you found the time to join the contest. :sunglasses:

The more you mod flashlights the faster and more skillful you get. If you build a flashlight in a short time maybe it is simple or it just seems simple to you because you are an expert.

Working with small flashlights is sometimes more tricky than with big flashlights.

Thanks for your words Skylight :wink:
Well, that expertise and experience surely comes with the time, but sometimes it is like starting from scratch when the project is different. This was the case :stuck_out_tongue:
Still, it was manageable and I am glad I could present it on the OL Contest!

But, it is surelly less demading than your builds, that are “go big or go home” as I mentioned in your thread :person_with_crown:

Thanks again and well done for you as well :sunglasses: