FW3A Useful Information.....

This thread was created to fulfill one of the simple “hopes” of ToyKeeper in THIS post.

It will contain very simple, but useful; information to acquaint you with your new FW3A.
Not everyone will need this information, but for those that do; here it is…… posted below in order of relevance for the most part.


1. Install a CHARGED battery from the head (front), positive to driver


  • You want to remove clip
  • You just want to… :wink:

3. Keep it tight

  • Driver retaining ring
  • Tighten tailcap first
  • Tighten head second

The FW3A uses the Andúril‎ firmware by ToyKeeper. Your FW3A comes with a detailed User Manual that explains this UI (User Interface) in great detail. Read it, read it again, read it until you understand it. That understanding will enable you to access & use the neat features available with the FW3A.

Please also read & understand page #11 of your FW3A User Manual. It concerns the Thermal Configuration of your FW3A.
This step of Indoor Temperature Calibration need only be done one time.
The light will operate without doing this step, but if you want the thermal sensor to be accurate…. do it.
For more instruction see post #3 & video in post #5)

IMPORTANT… Please read

The statement below was taken from The FW3A OP. read it & pay attention:

  • The FW3A has smooth thermal regulation to avoid overheating. However, turbo is a burst mode only, and the user should use it only for short periods instead of relying on thermal regulation to prevent heat damage. Full turbo is powerful enough to start fires in just a few seconds, especially when aimed at dark-colored materials.

If you want a bit of extra info about the FW3A also read THIS

Now… without further distraction, let’s begin with post #2.

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Getting aquainted with your FW3A

You have just received your FW3A(s), here are a few basic & simple things to do and check.

1. Open the box, it should contain:

  • 1 x FW3A flashlight
  • 1 x instruction manual
  • 1 x small bag of spare O-rings
  • 1 x instruction card telling & showing you to load battery from the head end

2. Remove everything from box & visually inspect your light for any external damage

3. Unscrew the head from your FW3A, check driver retaining ring for tightness, visually verify driver is properly seated, & then set head aside

  • If driver retaining ring is loose, tighten it.
  • If driver is not seated properly, fix it.

4. Check the tailcap for tightness & tighten if necessary. DO NOT REMOVE TAILCAP

5. When you are satisfied tailcap is tight insert a charged battery with the positive (+) terminal facing out, toward the driver.

6. After making sure of proper charged battery installation replace the head & tighten

7. Your light should now be operational

Please note:
If you ordered a battery with your light there may well be a clear almost invisible sticker covering the negative pole of the battery.
This must be removed to charge the battery & operate your light.

After removing the “sticker” check the battery voltage.
It should be around 3.4 V…

Charge the battery.
When charged, insert the battery in your light as described above.

Your light should now be operational

+If your light is not operational after taking these steps, please see Post #5 below.+

Care of your FW3A

Besides cleaning it if it gets dirty there is not much to do except, as with any light; clean & lube the threads and O-rings from time to time.

Wipe the threads clean with a rag and then lightly lube the threads and O-rings.

I use & recommend Super Lube Synthetic Grease for this because it is compatiable with any formulation O-ring.

If you use something else no problem.

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So you want to remove the clip from your FW3A

Ok, you now have your FW3A & you want to remove your clip. To do this you must remove the tailcap. Do it this way & you should experience a harmonious outcome…

1. Remove the head

2. Remove the battery

3. Point the head end of the battery tube at the ceiling

4. Unscrew the tailcap & set it down flat so it stays together

5. Remove the clip

6. Point the head end of the battery tube at the ceiling again

7. Reinstall the tailcap & tighten

8. Reinsert battery in proper orientation, positive (+) toward driver

9. Install head & tighten

10. You should now have an operational clipless FW3A

Thermal Configuration & Protection

Thermal configuration

Look at a thermometer to check the current room temperature. Let us assume it says 21 Celsius Turn the light off and wait for its temperature to settle to room temperature.

Go to TempCheck
When you are in TempCheck, then click 4 times to enter thermal config mode, and calibrate the sensor.

Thermal config mode has two settings:

1. Current temperature Calibration.

  • Click once per degree C to calibrate the sensor. For our example, the ambient temperature is 21 C = click 21 times.

2. Temperature limit.

  • This sets the maximum temperature the light can reach before it will start doing thermal regulation to keep itself from overheating. Click once per degree C above 30. For example, to set the limit to 50 C, click 20 times.

The default is 45 C (15 clicks).

Hint: If you don’t click, the lamp will leave the value unchanged.
The lowest value the user can set is 31 C, by clicking once.

°C…… °F
100… 212… Boiling Water
_60… 140
_55… 131
_50… 122… Touch limit
_45… 111… [Default]
_40… 104
_37,4. 99… Body temp.
_25…. 77
_20…. 68
__0…. 32… Frozen Water

MaxTemp. – 30°C = Clicks

+How to Calibrate the Temperature & Limit on Your FW3A flashlight with the Anduril firmware. / M4D M4X


Protection Features

Some features which aren’t visible on the diagram:
Andúril includes low voltage protection (LVP) and thermal regulation.

  • LVP makes the light step down to a lower level when the battery is low, and if the light is already at the lowest level, it shuts itself off.
    This activates at 2.8V. LVP adjustments happen suddenly, in large steps.
  • Thermal regulation attempts to keeps the light from overheating and otherwise adjusts output to stay as close as possible to the user-configured temperature limit.
    Thermal adjustments happen gradually, in steps so small they are difficult for humans to perceive.
    It ramps smoothly across 512 internal steps (from 1x7135 to full power) to adjust output while it searches for the highest level it can maintain without overheating.


Momentary Mode

To do this, set the light to your desired output, then turn it off. Click five times to enter ‘momentary’ mode.
NOTE: You’ll need to disconnect power briefly to exit ‘momentary’ mode. Any button presses will just make the light flash. You can’t ramp or enter any other modes while in ‘momentary.’ (by goshdogit)

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Tailcap assembly

Ok, for whatever reason your tailcap is in pieces & you need to reassemble it. No problem, don’t panic… it is not rocket science.

The main thing is… don’t loose your ‘nubbin’.

To reassemble tailcap:

1. Place tailcap body, threads up; on a stable flat surface

2. Install metal switch button, flat side down; in tailcap body

3. Install rubber washer, flat side down; in tailcap body

4. Make sure ‘nubbin’ is in flat washer & pointed up toward the sky

  • See picture of rubber washer & ‘nubbin’ below

5. Install switch with spring pointed up toward the sky

6. Point battery tube head end at ceiling

7. Install tailcap on battery tube & tighten

Nubbin & flat rubber washer/switch cover


Nubbin in proper position


More Switch Component Pictures


But…. I lost my ’nubbin’!!

No big deal… stuff happens. :wink:

You will however have to improvise & fabricate yourself a ‘nubbin’. The FW3A will not work without a ’nubbin’.
See the FW3A Troubleshooting Thread to find a solution to a “lost nubbin”.
Pro Tip:
If you lose your ‘nubbin’ or just want to secure your factory ‘nubbin’ better just reglue it.
There are many varying opinions as to which glue is best… in reality it makes little difference as long as it holds. I personally am gonna use a tiny dab of 3M 5200 on mine because I want them to be there forever & I also happen to have some 5200 on hand.
BUT AGAIN…… what I am doing to mine is not necessary. :wink:

If you do glue or reglue… do make sure the parts to be glued are completely clean.

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My FW3A won’t work or was working but quit.

If your FW3A quit working or does not work, check these two things first.

1. Is the battery sufficiently charged

  • If not, charge it

2. Is everything tight

  • Driver retaining ring - check for tightness & tighten if necessary (see details below)
  • Loosen the head
  • Tighten the tailcap very tight
  • Then tighten the head very tight

If this fails to make your FW3A operational go HERE

Driver Retaining Ring

A loose driver retaining ring can cause an issue. That issue is described below along with the simple solution.

Firelight2 wrote:
Discovered an issue today:

Several times now after inserting the battery at the head and then screwing closed the light I’ve noted that the head sometimes stops screwing down a couple mm before it should. This appears to be caused by the inner switch contact tube being slightly off-center and hitting the edges of the narrow driver retaining ring. When this happens the inner tube does not make contact with the driver and the light does not work.

If this occurs, the light can still be screwed down by unscrewing and then rescrewing the head in several times until things line up right. But that doesn’t solve the problem and is frustrating to do. This issue occurred with both my FW3As.

Analysis and Solution:

The problem appears to be caused by the driver retaining ring not being screwed tight to the driver at the factory. If you encounter this issue, use tweezers to turn the driver retaining ring so that it is flush against the driver. Once the retaining ring is snug, this problem goes away completely.

Driver Retaining Ring: Loose / Installed


steel_1024 wrote:
In addition to tightening the retaining ring.
Also align the 2 notches shown in the figure below.

NOTE: This driver retaining ring is very thin, but it is there. If you do not have the proper tweezers, a nail, toothpick, pointed fingernail file, etc. may be used to tighten a loose retaining ring.

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Threads, Posts, & Videos of Interest

Threads & Posts:

Mod Threads:


Neal - FW3A Assembly


M4D M4X - FW3A Switch Assembly


M4D M4X - FW3A Video Review


Anduril Configuration starting with Thermal Configuration / by ZozzV6

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Miscellaneous Information

1. Batteries

  • The FW3A takes 1 x 18650 Li Ion Battery. Flat top batteries will fit as will most button top batteries. Your particular button top could be an exception.
  • Protected batteries will not fit
  • Either High Drain or High Capacity battery may be used. Performance will be about the same. Run time will be extended with High Capacity.
  • Sanyo/Panasonic GA - LG MJ1 - Samsung 35E - Samsung 30Q, to name a few

2. Optics

FW3A Optics

  • Glass AR coated lens 23.0 mm x 1.5 mm
  • The optic is a Carclo 10511, which is a lightly frosted optic with a relatively narrow spot. It gets almost as much throw as the 10507 optic, but with greatly reduced tint shift and artifacts.
    The 105xx Series Carclo Optic may be easily replaced or interchanged in the FW3A if needed or desired.

Beam angle comparisons between four Carclo optics:

Frosted Carclo Optics

  • The 10511 is called a narrow spot. 22°
  • The 10508 is called a medium spot. 27°
  • The 10509 is called a wide spot. 40°

Clear Non-Frosted Carclo Optic

  • The 10507 is called a narrow spot. 18°

Buy Carclo Optics:


  • The FW3A uses a standard 20mm Triple MCPCB compatible with the Carclo 20mm triple-TIR optics.
    Noctigon & similar 20mm Triple MCPCB’s should fit in the FW3A just about perfectly should you wish to modify your FW3A.

These can be purchased from many places easily. GOOGLE is your friend.

4. Accessories

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Part time job as a scalper i see :stuck_out_tongue:

Wow....lots of reservations here. :-P

Can't wait to see what this will be about.

Some ideas - probably you’ll be doing these anyway but just thought I’d pop them in! :+1:
Optics, I believe there were 4 (item numbers 10507, 10508, 10509 & 10511 I think and what they do to throw etc) and where to buy them - I did see it in the main thread but like all the info it’s lost forever in a million posts.
Holsters that fit
Modding bits, glow tapes/ disks, trits etc. Someone even did drilled optics, but they were a little expensive for me sadly (a lot of work is involved in making them though)
Diffusers for the ‘play’ modes lightening , candle etc - the rubber cone/dome things
Batteries - their pros and cons with this particular light

I guess more ideas will follow from others when they get their lights and start playing :partying_face:

Thanks for the ideas Goose. Ideas welcome… :wink:

Yeah I’m working on it & should have it up later today after I get finished with a doctors appointment.

Last night TK asked a volunteer to do this… I could not refuse the ‘Light Goddess’ and the rest will be history. :smiley:

@ Lux-Perpetua…. Yeah… I went “reservation” crazy. :smiley: I figured better to many than not enough. I’ll just delete the unneeded ones later. :+1:

I'd have to say, I have some... reservations about this thread...


:smiley: …. You won’t be dissappointed. :wink:

Would it be more useful to put the issues and fixes into a spreadsheet rather than another BLF thread?

Just thinking out-loud….and thanks for taking this one :+1:

Soon… ALL of BLF will be FW3A :smiley:

CRX, i’m waiting for you to add your custom switch with trit installed to this thread. Then, I can PM you and you can take my money.

Maybe some smaller trits in a triangle around the tiny plastic switch nub?

My light is on it’s way, traveling by Yodel, which is always fun :laughing:

From the pictures I have seen, for a single central vial install it looks like the centre nub in the steel cover can be ground down/ slotted, a hole or slot into that with a 6mm x 1.5mm trit & UV glue and then some playing around with the nub on the rubber switch boot. Maybe also use a thinner vial there.
Or as you say three trits in a triangle shape etc would look really nice too.

This is not going to be about mods or anything… it is just going to be a listing of simple things that TK can put a link to in the FW3A Thread OP… according to her…. IIUC.

I know …. Yodel! same here!
I’m kinda surprised someone on here doesn’t sort of mass produce some trit switches for this, once programmed the time and cost would be minimal - next to no materials either and the milling would take a matter of minutes. I could make some on the lathe, but no milling option sadly.

Thanks you for creating this thread, teacher.

I'm sure it will help a lot of BLF members.