Quickie #5: Inside of the Fenix LD12 tail switch

The Fenix LD12 is quite powerful (125Lm) and small size (powered a single AA cell); the flashlight is quite tough with it aluminum body but it has two weaknesses : the rubber capped buttons.
Although i found a way to protect the side switch, i still didn't found any good way to protect the tail one.

But... Before trying to protect it, what's inside?

Let's open it

From Left to right :

• A Circlip, that holds firmly the switch into place AND make contact to close the circuit between the switch and the flashlight body.
• The switch (with click and momentary ON features.
• A washer that press on the rubber cap to keep everything sealed and waterproof
• The rubber cap
• The tail body
• The whole Tail switch

The switch
A closer look

Here we have a simple two sided and circular PCB, with a mechanical switch on one side, and a spring on the other one.
To pass through the PCB, a simple tin droplet in a hole makes contact between both sides :

The spring is held by three tin droplets that pass trough the PCB to connect the switch races.
The switch features both ON/OFF by full click and momentary ON by pressing gently on it.

Fenix went far in making the rubber cap: they even added their brand logo:

Note that this rubber cap is dead already:
I would have liked a lot if Fenix had supplied spare rubber caps with the flashlight...

What's next?
Planning to make a remote switch

As i have two tail bodies, (and everything twice, only the rubber cap has no working twin here), i am planning to make a remote pressure switch based on what Fenix made for their bigger products :

Quickie #2: protecting Fenix LD12 side switch

The Fenix LD12 is quite powerful (125Lm) and small size (powered a single AA cell); the flashlight is quite tough with it aluminum body but it has two weaknesses : the rubber capped buttons.

To keep the flashlight waterproof, these rubber capped buttons needs not to be altered. I already needed to change the back On/Off button due to untimely leak but its construction doesn't allow to protect it; though we can protect the side button (replaced by a steel capped button on cutting edge Fenix flashlights!)

Which material could be used for that purpose?

A few possibilities were allowed to protect the side buttons. We needed the material to respect some characteristics :

• Being firmly wrapped around the LD12 body
• Strong enough not to get worn to quickly
• Springy enough to allow the button under it to be pressed

What about using heat shrink tubing usually aimed toward electrical isolation?
When heated these tubes shrinks and wrap firmly around the underneath material (whatever it is...).

It is available in a large range of diameters : at home it had it in 1,3, 4.5 and 6mm... but it exist in 12.5, 25 and even 35 or 75mm...

Once shrunk, it resists quite well to tearing, scratching and break through (i used a dentist toothpick):

It looks like the perfect candidate for the job!

Let's wrap!

1. Cut the tube at the right length, with heat it will shrink (in diameter) but length won't be altered
2. hold the tube carefully: mainly if it was stored flattened.
3. heat gently a little area with a soldering iron until you get one shrunk ring (3-6mm wide), starting from the collar
   
   (NB: try to heat homogeneously or you'll get thicker areas where the tube gets heated too long)
4. repeat, moving little by little until all the tube has shrunk firmly around the body and press with your fingers after each step -before it cools down-(take care not to overheat the side button!! if your fingers are burnt while pressing... it was too hot!)
5. finish with the Flashlight head
   
6. re-heat area that aren't shrunk enough
7. Press button area after heating a second time to get the button layout appearing (heating too much will make the tube thicker and you won't see the layout after pressing)
   

The Flashlight is now more wear/break-through/scratch proof (the side button at least). The result is far from perfect, but that was a first try!