Help me unscrew this tailcap ring and find cheap replacement parts

Flashlight Modding and DIY Parts
1

This is a tailcap from Xiaozhi (bought at FancyFlashlights), the switch PCB board is not centered and it’s upper left corner is UP by the height of the brass ring.

The brass ring is stuck in there due to the amount of friction and just won’t unscrew :frowning:

The rubber boot was teared a bit and is stuck just on that side where the board is lifted. I teared the rubber boot off since I want to replace it with lower one.

I’ve desoldered the spring for easier access and overview.

The aluminum ring on the boot side can be moved around with a screw driver, it’s not easy but possible and doesn’t help a bit.

Options I see:

  • destroy the PCB with a drill bit and hopefully save the ring and switch
  • destroy PCB and a switch
  • drill bigger holes in the brass ring and try to unscrew it somehow without destroying anything
  • heat the whole thing up and hope for the best that it will unscrew (should make less friction with the tailcap aluminum body)
  • hammer the PCB down below the ring on that one side somehow, but I don’t think that is potentially helpful

Tools I have a drill and a small drill for precision work, can drill small holes 1mm / 1/25th inch minimum.

It’s not a problem to hold the tailcap or to keep the tool in the holes, the problem is that every tool I use to unscrew it bends.

And yes I’m unscrewing it counterclockwise and the thread is counterclockwise to unscrew.

Now, where can I get this switch? Or just a nice gold plated pcb for a switch?
Or the 20mm brass ring?

How is the switch attached to the PCB? Anybody has a close up picture? Can I even get the PCB out, drill it, dremel it away?

Any tool I could use to unscrew it? Hopefully with two very strong tips.

Questions about XIAOZHI CREE XM-L T6
2

Small needle nose pliars.

3

Heat the tail cap with a torch. Do not heat too long. Just get it hot to where you can't touch it. Heat all the way around and then use needle nosed pliers or snap ring pliers to turn the ring out. Also you can use some WD-40 on the threads, but the thing is probably glued in, so heat should do it.

As far as the rest, the switch is soldered to the PCB. When you take it out, you can replace the rubber cap and put it together and try to center it a little better. Once you have it apart, you will see it better.

4

Sorry I can’t help myself, it’s Chinese new year, shove a firecracker or two in there and light it up. It’ll breakup the glue.

5

What? They glue in the tailcap brass ring?

The head wasn’t glued in. Is that a common practice?

Ok I’ll have to search more tools, since needle nose pliers are too big, I doubt we have smaller ones. Maybe somewhere hidden might be the snap ring pliers but I haven’t seen them for years.

What could I use to heat it up and not destroy the plastic switch? No torch around.

6

Yes, sometimes rings are glued in..

A soldering iron could work to heat the ring or maybe freezing it.

If all goes wrong, it shouldnt be too hard to find a replacement switch. Those are nothing special.

7

Based on alu and brass expansion, heating could help.

8

Alright, just unscrewed it, put it on a baking paper on a pan before cooking XD
Tried to unscrew it and it went very easily after it heated up.

Dunno if there was any glue I can’t see or smell anything.

The switch board is bent, probably they have screwed it too much in, there is some brass dust/bits in the thread too…

So horay, unscrewed without any damage.

9

yoho and a bottle of rum!