FW4a Replacement switch

Flashlight Modding and DIY Parts
1

Hey all, I’ve seen peoples posts of adding O-Rings to their FW series lights in order to give the switch more actuation force. What I was wondering was wether anyone knew of a place I could purchase a replacement switch with higher actuation force ‘from the factory’ rather than adding an o-ring.

Any help appreciated.

2

I also need a replacement switch for my FW3A. I messed up the tail switch when I changed the tube from 18650 to 18350. Now the flashlight is NOT working.

I have asked Neals Gadgets, where I bought the flashlight during the Father’s Day Sale in June, and Lumintop China; but no information.

Lumintop China advised me to “reassemble” the tail switch. But I cannot.

Lesson learned: Don’t open the tail switch of the FW3A.

3

The switch inside the FW3A is extremely simple. It consists of a plastic switch board, a metal switch actuator made of a single piece ofstamped spring steel and a piece of Kapton tape holding the actuator onto the board. I believe the switch PCB and the spring steel actuator are custom-made for the FW3A.

The designer likely chose to go with this setup rather than using an off-the-shelf switch in order to save space. The FW3A’s switch is incredibly flat. It’s barely taller than the thickness of the switch PCB. This saves room inside the light allowing the entire light to be shorter.

The switch pcb is custom to the light, but the stamped metal dome switch on top appears to be an off-the-shelf part. It can be replaced if you find a different one and use some fresh tape to hold it in place.

To increase tension without replacing the switch, you might try:

  • Remove the actuator from the Kapton tape and try bending the 3 legs down. If you don’t break them maybe it will require more pressure to activate; or
  • Get a piece of sheet spring steel and try making a new stiffer switch actuator (by cutting it into shape with scissors and bending with pliers; or
  • Do the o-ring mod… it’s fast, easy and completely reversible.

What did you mess up when you took apart the FW3A’s switch? It’s so simple there’s virtually nothing inside it to break. Did you lose the nubbin that sits inside the divot in the switch boot?

4

Regarding the o ring mod, the issue I have is that my light has a retaining ring and I can’t undo it?

Any help there.

5

Try inserting tweezers into the slots on the retaining ring and turning. Or needle-nose pliers if you need more force.

6

I’ve already tried that to no avail.

7

There are other tools that can be inserted that allow more force. But I’ve never needed to use them on any FW series light. The tailcap retaining rings might be tight, but they aren’t glued.

Removing the tailcap retaining ring is just a matter of leverage, the right tool, and musclepower. And making sure you unscrew it the correct direction.

If everything you try doesn’t work, your options are limited. If you do not remove the tailcap retaining ring you won’t be able to perform any internal mods on the switch. Some options:

  • Check the forums for tips on removing retaining rings. Others will the name of better tools for it. I don’t recommend snap-ring pliers though. I have some, but needle-nose pliers just work better; or
  • You can destroy the tailcap retaining ring. Insert something thin, such as a small screwdriver under the retaining ring and then use it as a lever to deform the retaining ring inwards. Once it is deformed, you can snip it with some wire cutters and then yank the remains out with pliers. FW series lights don’t actually need the tailcap retaining ring. The first versions didn’t even come with it. It’s just there to prevent the switch guts from falling out if someone accidentally unscrews the tail. If you destroy the tailcap retaining ring, you will then be able to access the switch guts for the o-ring mod. or
  • You can glue a washer to the back of the tailcap. That’s another mod some have tried. A washer glued to the back turns the flush switch into a recessed switch, making accidental activation less likely.
  • You could try sending the tailcap to a modder to remove it; or
  • You could just use the light as-is.
8

There are literally thousands of click dome designs on the market. Every manufacturer has a huge selection of various forms, actuation force or distance.

9

Where do you find parts like that? I saw someone on Reddit so an incredible mod recently and they had dovens of switches they bought to try out. Just wondered where people find such things. I would love to change some other lights switches.

10

You’re right!

A quick Google search for “10mm Dome switch actuator” reveals dozens of links to shops selling them in different sizes and with 3 or 4 legs. Turns out the actuator IS a standard off-the-shelf part.

Note that my Google search was just a quick off-the-cuff thing. I didn’t actually measure the dome switch in the FW3A so it might not be 10mm. Measure before ordering.

But given this, it should be possible to replace the dome with a stiffer one. All you need is to buy an appropriately sized replacement dome and some Kapton tape.

HOWEVER:

  • A quick check on Digikey showed their 10mm dome switches go up to about 14 oz of activation pressure. This reminded me that TK mentioned the original batch of FW3As required 14 oz to activate, but later Lumintop switched to 7 oz.
  • I have both versions and personally found that even 14 oz activated much too easily in the pocket. I do not know if they are available with activation pressures heavier than 14 oz elsewhere.
  • 14 oz activation pressure also means the pressure needed to activate is still less than the 7 oz plus o-ring mod.
  • What worked best is a 14 oz dome switch combined with o-ring mod. In one of my FW3As with the original switch, the result was an activation pressure of over 5 lbs! Stiff enough that you could balance a BLF GT on top with batteries inside and not trip the switch. Definitely stiff enough for pocket carry with no lockout and confidence it won’t turn-on in the pocket.
11

Have you tried Lumintop Online?

12

If you look at CRX’s post, LINK, you see that it’s a triangle metal dome switch with no legs, though the holes are there for one with legs, but a circle with dimples should work too.

With a little searching around I came across these, LINK. The 9mm triangle with no legs (part # M9T-1800-D) should work because of the large exposed contact trace that can be seen in CRX’s post, this would give 1800g of force needed to activate. You might be able to place the 11.5mm with no legs (part # M11.5T-2000-D) 2000g activation switch over the 9mm 1800g activation switch to increase the total force needed to activate, but again we’re back at a two item solution to the problem.

The overall problem looks to be the ability to purchase these items. Best technology is the only place that I could find with a high activation force, most others maxed out at 400g, and the only ones I saw on Ali were 350g.

13

Thanks for this tip, Speed2z28. I will order one tail-switch from this platform this morning.

When I said I “messed” up the tail-switch, I meant: I forced open it to change the tube from 18650 to 18350. Somehow, parts in the tail-switch broke loose. And I cannot switch on when changing it into 18350 tube and battery. When I reverted back to 18650 tube and battery, the tail-switch also wouldn’t work. It doesn’t stay in one operating unit like before. :rage: :person_facepalming:

14

Probably you’ve lost the little plastic nub. You will need it for every tactile switch. A new dome won’t help. Try to find a plastic rod with the correct diameter (2 mm?) and cut it to the right length.