FW3A e-switch sensitivity workaround/mod: 3D Print a Magnetic Tailcap that prevents accidental activations

Hey all, got my first fw3a a few days ago and it kept turning on while attempting to edc it.

Lockout is too cumbersome so I 3D modeled a cap to protect the switch. It also houses a 20mm OD tail magnet from banggood.

I put the stl here so anyone can download/print/remix it. scale to 102%

I also put it on my site if you don’t have a 3d printer and want one.

Lmk if you have any ideas for different/better designs.

Nice, I may have to try this! Thanks for posting.

Nice mod :+1:

Cool :+1:

I’ve found that a fixed surround with a flush 8mm button is also good to prevent unwanted activation.
It can’t be pressed from the side etc and a much smaller button area to press.

I made a carbon fibre piece with embedded neo magnets fixed in the tailcap with centre button.

For those with printers I thought that you could print out something similar, a switch housing unit with centre button that fits into the tailcap, possibly even making it so the switch is slightly recessed.
Just another idea.

Very sweet work my friend. I think you and I have approached this from opposite ends of the spectrum - I went for speed and MVP. Total time spent including design work & waiting for 3d printer: about 30-45mins. I’m guessing you gave yours a bit more TLC?

I looked at your linked thread but didn’t see a lot in the way of a how-to / guide, in particular, would you mind sharing with us your parts list with Urls? I realize you’re in (Scotland?) another country but just seeing the exact item names will help me source similar components for future flashlight/small device mods/upgrades like the one you suggest.

Thanks & cheers!

PS, do you sell replacement tails like yours? If not, could you estimate parts & labor cost? I’m curious from an intellectual standpoint. And if the price was right I’d buy one maybe on a future light.

Thanks, yeah I was suggesting to print a similar design as it would be much easier to make and fit for people who can’t mod.

I won’t link all the items but I’ll tell you what I used.
My methods are all about finding stuff and making it fit together using simple hand tools, use any technique that works, mostly… :slight_smile:
My FW3A tailcap mod makes use of 14mm x 12mm 3k carbon fibre tube, 15mm x 14mm brass tube, 2mm x 3mm N52 neodymium round magnets, 8mm x 2mm steel bike chain spacer, 6mm x 1.5mm green tritium vial, UV setting glue, JB Kwik weld, 0.5mm silicone sheet plus the E-switch mod.
Kapton tape, cottonbuds, silicone grease, wooden toothpicks, paper towels, JB weld, scalpel blades etc are also consumables I use a lot of.

Maybe two to three hours work.
Difficult to explain the method and I’m not very good at explaining :smiley:

So basically you would shape the CF tube to the correct size to fit into the tailcap hole, protruding through maybe 0.5mm on the inside and flush with the tail, press into place with something flat, check sizing etc.
I used a very thin piece of brass tube on the inside too for extra support but it’s probably not needed.
Once happy with the formed CF piece JB weld it in place with the tail cap facing down placed on a flat hard surface making sure it stays level with the end of the tailcap. Careful not to epoxy the whole thing to the flat surface.
Tidy up the JB weld before it fully sets, acetone on a cottonbud works for this.

Once set arrange the magnets on a lightly greased flat steel surface, apply JB weld and place the tailcap with the CF insert into place around them maintaining correct positions in a circle as best you can and tidy up/ press the epoxy with dampened cottonbuds, excess can be removed later.
The magnets stuck to the steel keep them level so you just need to keep the tailcap flat and magnets in place around the inside edge of the CF tube.
If you could find a suitably sized ring magnet this would be a lot easier.

I used thin flat silicone sheet in place of the original rubber boot, cut to fit, siliconed in place with a silicone o-ring in the original boot groove.

The button, made from an 8mm steel bike chain spacer I think, is dremmeled out on the underside to fit the tritium vial and UV glued in place, again using the flat surface method but using clear tape to make it smooth on the outside face.
The magnets will actually keep this in place but a little silicone on the underside to the silicone sheet can be applied too.

As you can tell, this is something that can’t really be made to send out which is why I thought a similar printed version might be an idea.

Can you print these in colors close to the original light color (purple or blue/grey)?

Awesome info thanks for the write up! Wow you sound like me (hopefully) in 10 years. I thought you had dedicated equipment for your mods, not random bike chain etc. Totally awesome. Will have to reread everything when on desktop.

Yes in theory but I live in a mobile tinyhouse (skoolie) and I already have about 10 more extra spools stored than I have space for… If enough people wanted a certain color, sure. There are some online services (like shape ways.com) where you can order a 3d model printed in a material of your choosing. If you look into it pls report back your findings (if they have the color, cost etc). I’d be curious

It would be nice if Lumintop just inset the switch a little more instead of making a billion FW variants.

I just glued on a ring magnet.

i edc my lights and have never gotten glue to hold for more than about 2 weeks.

i usually use gorilla glue gel extra strength super glue, set, then reinforce with UV epoxy. what glue did you use and how many drops/magnetic mounts has it survived so far?

Gorilla glue gel.

Cleaned a roughened both surfaces, so far all good.

The six hour setting JB weld would be better for attaching magnets.
File off the nickel coating, clean with blutak to remove the bits then solvent clean.
Also might help to file down the ano if you dare and leave a rough clean metal suface.

You need only scuff and rough the nickel when using JB weld. It holds better to the nickel than the bare Neodymium surfaces.

I just ordered two. I'll post up when I use them :D.

Sweet. Did I make it clear that it doesn’t come with the magnet? On my reddit post I mentioned I don’t have enough to include them just want to make sure you saw the banggood link…

But does the JB weld hold better to the nickel than the nickel holds on to the magnet? :smiley:
The reason I suggested removing the magnet coating is because I’ve had it come clean off a few times, stuck to the weld, seemed to be a weak point. YMMV of course.

I see your side also. The nickel can shear/break off the neodymium.

How’s this?

I like the color of that filament :D