FW3A mod thread. Post yours!

Glad that worked out well for you

Ti bezel and 18350 body would certainly jazz up my Cu units, I’m in!

So, I have some plans I want to try - I finally got myself to order a programming device. Background is, that I want to use the light mostly in momentary mode on turbo but be able to use regular modes if I need them.

  • Does anyone know if there is an unused input pin on the chip for a second switch?
  • Are there schematics online somewhere?
  • Are there just the PCBs available to buy for cheap maybe (cheap as in I don’t have to buy a whole FW3A if I fry a board)?

Anyway, here we go:

Plan A:

  • Alter firmware to make flashlight always be in momentary turbo mode, defining a sequence to leave it and go either into a slimmed down Anduril or some own modes. Turning the light off will make it be in momentary mode again.
  • This should be doable without any hardware modifications except desoldering and resoldering to get to the microcontroller - I think I can do that if I invest enough time to alter the firmware

Plan B1:

  • Alter hardware to add a secondary switch on the side. This secondary switch will be connected to the the pin the tail switch is now connected to, Tail switch will just go to turbo, bypassing the microcontroller
  • I don’t know yet if it’s possible to simply bypass the microcontroller for turbo
  • If it’s possible, the light won’t have any LVP in momentary mode anymore.
  • There is only momentary the tailswitch can do, nothing else and there is no easy way to change this.

Plan B2:

  • Alter hardware AND firmware to add a secondary switch on the side. This secondary switch will be connected either to a free pin of the controller or maybe via voltage divider trickery to the same pin as the tail switch
  • All functions should be doable via firmware
  • LVP should stay intact
  • This will require a load of work

I think I have the skills to rewrite code to make it work, but I lack mechanical abilities/tools/knowledge to fit a side switch into this thing. I could design and 3D print an outside part in ABS that can fit a switch and drill a hole for the cables (and order a metal 3D print if that works and i’m happy with it). I thought about replacing the whole middle part with the shelf with a metal 3D printed part but I don’t think this will work out because of the threads - metal 3D printing is not that exact.

But again, only if I find enough time and motivation to do so.

Was it hard to do the swap? I imagine it’s just desoldering the 4 wires, remove the top and bottom boards, and just reflow?
Just wondering if there are any hidden surprises or tips I should know before I do it. Thinking about putting some 219b sw35 in mine.

No need to remove the driver if that’s what you mean by bottom board.

If you have the later batch of FW3A they come with a small screw in the shelf and a divot on the underside of the MCPCB to keep it from spinning when you screw the bezel on. I would re-use this one if you are able for that reason. If you don’t want to re-use it you need to remove that screw so it sits flush.

If you have the very first batch of FW3A you can re-use the MCPCB or use an aftermarket one. After you have everything soldered back in place you might want to spin the MCPCB a quarter turn counter clockwise so when it spins while cranking the bezel it wont pull on the wires.

On mine they only used wires exactly as long as they needed to so if you use an aftermarket PCB where the wires are further out it may not reach without replacing them. YMMV.

So there aren’t 2 boards where the MCPCB is? One for the main emitters and one board for the secondary LEDs? I wasn’t referring to the driver. I have the first batch of FW3A I think.

There would be.

Except that the FW3A does not have any secondary LEDs.

If you want secondary LEDs in your FW3A you have to buy a custom secondary LED board from Lexel. That custom board sits on the star just like the aux LED board on a D4v2 or E07.

Did you buy a modded one with secondary LEDs or are you mistaken?

If the secondary LEDs are those “dragon” type they will be on the same board as the main LEDs so you would want to re-use that board and leave them on during re flow. I guess this is why you said 4 wires.

I’m so stupid… I was totally thinking about my D4v2… wanted to swap the emitters on that one.

Ignore my previous messages… haha.

I’m interesting in how you fare doing the D4v2. It does have an aux board but it seems like to me the most tricky thing would be fitting those 4-5 wires (edit: 6!) back through the MCPCB hole after they have soaked up some solder making the wires stiff. Seems like there’s barely enough room as is.

D4v2

No problem. I was kinda thinking that was the case actually.

My D4v2 hasn’t arrived yet, but my understanding is it uses an Aux LED board that sits on top of the main board.

  • There are 4 thin wires connected to the aux LED board. All 4 must be desoldered.
  • Then lift off the aux LED board to get access to the star, which has the normal 2 wires.
  • Use a fine-tip soldering iron for the aux LED connections and a heavier tip for desoldering the star.
  • Before desoldering, take pictures so you know the proper pads to resolder each of those 4 wires.

If you’re having trouble threading all 6 wires through the hole in the star, do the following:

  • Solder a long narrow gauge guide wire onto the end of each of the original wires. A couple inches should be enough for each guide wire.
  • Thread the guidewires through the hole in the star.
  • Slide the star down along the guidewires until in position on the shelf. Use the guidewires to pull the original wires through the hole.
  • Desolder the guidewires.

Swapping emitters is quite doable on lights with aux LED boards, but it is a much more complex operation than doing so on a light without the aux LED board. Leave lots of time for the project and take a slow and methodical approach.

Thanks for the tip. I’ll post pics if I decide to do this. Will probably swap the emitters on my FW3A as well so I wouldn’t be hijacking this thread… lol

Hi, who is selling the glow rings?

I think you can get them from Neal (Here), CRX (Here), or anywhere else that sells glow gaskets for 20mm Carlco triples.

Alternatively you could make one yourself using these instructions: DIY Glow Gaskets for Triples and Other Glow Stuff

Beautifully crafted response :slight_smile: thx

You are welcome!

I tried a UCL 22.61mm x 1.90mm lens on my FW3A, and was disappointed to find that it created a slight gap between the bezel and the rest of the head. With the original lens, the fit is so good that the head appears as one piece.

Maybe I’ll try the sapphire lens that Neal sells or TK’s method of polishing the coating off of the original.

To expand on this idea, for anyone that wants a magnetic tail cap, I am considering using one of these to do the same. They are basically neodymium washers. My only apprehension is the 2mm thickness, but I don’t think it will be that bad.

EDIT: Also I found a pull force calculator for ring magnets and these should hold about 4 pounds which should be sufficient for the FW3A.

Neodymium magnets are brittle, so they may not last a lifetime when mounted so exposed.

I had considered that. I was hopeful since they are at the lower end of the scale for neodymium magnets for magnetism that they would be strong enough.