Finally I beat Fenix FD40

clemence · 2019-09-01T20:07:45.000Z

Received the flashlight from Pavlo about a year ago. The plan was to replace the stock low CRI XPL-HI with any high CRI LED. But Fenix is well known to love blue and red thread locker. Even the blue thread locker they use which designated to be removable is almost unmovable in many cases. This is my longest fight, because we really want to put as little damage as possible for this is a very fine light. Flat regulation, sensible output, unique efficient zoomable TIR optic, great built, completely waterproof zoomie, ultra reliable, and…expensive.
I decided to try to open it only whenever I have free time to avoid frustration and too keep up my “will power”. So far, this is the HARDEST light to open for me! With no spare optic available easily, no destructive prying is possible. And I’m glad I didn’t do any brute force on it.

Original FD40 image taken from Fenix website. I forgot to shoot it.

Making hard wood clamps:

First try, broke the weak aluminum C-clamp.

Second try, stronger steel vise. Heated it carefully to no more than 120°C to preserve the PMMA optic. I glued a thermocouple to a location near the joint I worked in.

First encounter with the thread locker!! Fenix was very generous about it. Not a drop or two, they bathed the thread with it

This is “just” a blue grade thread locker. Just imagine what if Fenix used RED grade…. :confounded:

Now Only the head assembly left to open. Took me several months to figure things out. Heat it to 120°C, soaked the whole head in a warm kerosene batch for days, ultrasonic it, X-ray it, bang it, twist it, freeze - thaw it, asked nicely, etc….to NO avail

And last month I decided to try my last fight. The plan was to make a special wrench OR destroy the TIR optic to see what needs to be done (I was afraid it uses counter clock wise threading). I decided to make the wrench from aluminum scraps. This is the most expensive removal tool I’ve ever make to open a flashlight.

Part of the head removed effortlessly at ~240°C. Being aluminum I had to work very fast, it cools down rapidly. My hands got burned in the process too. Went all out. put the whole head on my hot plate and heated it to 240°C. I can always custom order the TIR optic. It’s been messing around for months and now it’s time to melt it!! :smiling_imp: To my surprise, the PMMA optic survived! The only visible damage is the frosted part is now slightly clearer, Everything else looks the same and still collimate the beam as it used to be.

Look at that, there are still some more parts to be removed :weary: . And these last parts were the hardest to clamp with no positive grip (hence the special wrench was needed) and silky smooth anodized surface.

Making the wrench

Perfect fit, with just enough clearance

VICTORY!

UPDATE 190903: More detailed high resolution images uploaded. Click to enLARGE

Very complicated and not many flashlight made from this many body components (except the electronics) like this one. Closer look at most of Fenix lights, although the model are mostly looks “boring”, Fenix sets a very high standard for all their lights. Flawless finish, top notch quality control, everything are well though and not just an afterthought add on features. Perfect knurling for $100ish price point. I’ve seen a light more than ten times the price with defective knurling. Even the well hidden glued internals are perfectly machined. Next time I get a Fenix, I will not complain about the price. Solder joints are all very well made. This is the only made in China flashlight with true Pb Free execution (read: PITA to desolder)

Zooming mechanism. The inner part is fixed to the body, only the outside parts are movable (threaded to the head assembly)

The MCPCB sits on the pedestal and the wires made from very thin copper sandwiched in polymide socks. The flat wire connected to the second FR4 board.

Then a plastic cover hide everything to prevent any artifacts or shadowing. This plastic cover also secure and presses down the MCPCB to the pedestal (Sandwiching the base FR4 PCB to the base using 2x M2,5 screws).

Defrosted TIR lens (the inner side center was frosted) due to heat used in removal process

Plunger style high quality stainless steel switch (secured with circlip)

I giggled in awe when I saw this precision made 18650 BATTERY SPACER. Other brands use cheap plastic tubing, but Fenix made it from silky smooth perfectly round anodized aluminum! The spacer secured by a ledge at the base. Why not just plastic? IMO, this is a luxury impractical stuff.

To those interested in FD40 driver. I did y best to capture all the part numbers on the components:

If you guys need more detailed information, just let me know. I haven’t found any tear down pictures of this rare FD40 anywhere.

[Clemence]

Terry_Oregon · 2019-09-01T20:26:52.000Z

This is my favorite 26650 light. Won't be taking it apart though. Interesting to see what's inside it.

djozz · 2019-09-01T20:29:44.000Z

SKV89 · 2019-09-01T20:32:01.000Z

Wow. I tried everything I could to open up the Rofis MR30 and MR50 with all kinds of tools and the body is all scratched up now but still won’t give. I really hate it when manufacturers use glue.

goshdogit · 2019-09-01T20:41:05.000Z

Well done! Congratulations and thanks for sharing your process!

Looking forward to an update.

Will you be using red threadlocker to give yourself a challenge for the next mod?

Yokiamy · 2019-09-01T20:55:10.000Z

SKV89:

Wow. I tried everything I could to open up the Rofis MR30 and MR50 with all kinds of tools and the body is all scratched up now but still won’t give. I really hate it when manufacturers use glue.

Use some rubber to protect the light while trying to open it. Since i live in NL, well known for bicycles, we use old inner bike tyres for many purposes

clemence · 2019-09-01T22:39:47.000Z

goshdogit:

Well done! Congratulations and thanks for sharing your process!

Looking forward to an update.

Will you be using red threadlocker to give yourself a challenge for the next mod? :partying_face:

I removed some lights with red threadlocker before. The toughness truly depends on the thread designs. Square glued threads are harder to open. Triangular threads have sharper peaks which helps to “cut” through the cured glue. FYI, Armytek almost always use red threadlocker. I will post the update after I cleaned all parts.

Yokiamy:

SKV89:

Wow. I tried everything I could to open up the Rofis MR30 and MR50 with all kinds of tools and the body is all scratched up now but still won’t give. I really hate it when manufacturers use glue.

Use some rubber to protect the light while trying to open it. Since i live in NL, well known for bicycles, we use old inner bike tyres for many purposes

When you work with heat the inner tube or whatever rubbery material used will soften and actually reduce the grip. I use either wood or soft aluminum for removal clamps. But in this case I need the heat insulating property of wood to keep the stuff hot during the process.

Note: for tough to open threads, you need more clamping force. To put more pressure without deforming the stuff, you need relatively rigid clamp with full circling enclosure with just enough clearance to slid the clamped stuff in. Picture how a motorbike front shock absorber clamped to the hub.

[Clemence]

Pavlo · 2019-09-01T23:28:16.000Z

Now that is what I call dedication to open a light without destroying it, well done Clemence.

Enderman · 2019-09-02T00:29:04.000Z

Pretty sure they don’t use threadlock, it’s straight up glue.

yasenf · 2019-09-02T04:02:51.000Z

I also love both my FD40 and FD41 and always wanted to change the tint to 5D, but after seeing this thread, I will not even try I admire your persistence and dedication.

CRX · 2019-09-02T04:35:30.000Z

Perseverance from the clemence

Phlogiston · 2019-09-02T05:58:57.000Z

djozz:

That makes two of us. I am extremely impressed.

SKV89 · 2019-09-02T06:35:14.000Z

Very curious what emitter you plan to put in there? That mcpcb looks too small to fit a quad E21A

clemence · 2019-09-02T22:59:00.000Z

UPDATE 190903: More detailed high resolution images uploaded.

[Clemence]

xenotar80 · 2019-09-02T23:15:03.000Z

Phlogiston:

djozz:

That makes two of us. I am extremely impressed.

same here. this is next level.

breaking open and modding the wizard pro is nothing compared to this hahaha… literally nothing.

clemence · 2019-09-02T23:27:59.000Z

But for someone who NEVER use a soldering iron and mod any light before, you SUCCESSFULLY modified a Wizard Pro from scratch! People still talk about it Bryan.

[Clemence]

xenotar80 · 2019-09-03T00:53:03.000Z

clemence:

:laughing: :partying_face:
But for someone who NEVER use a soldering iron and mod any light before, you SUCCESSFULLY modified a Wizard Pro from scratch! People still talk about it Bryan.

[Clemence]

haha with great instructions and coaches

prototype3a · 2021-05-26T00:49:57.000Z

WOW.

I too love my FD40 but like you, I wish it had a high-cri LED.

If Fenix made them again with better LEDs, I’d buy one instantly.

prototype3a · 2024-08-28T19:00:15.920Z

Bump. LOL