After playing around with my new Trustfire X9 I once again have stumbled onto a problem that seams to occur time and time again with my lights. The connection in the tail-cap keeps breaking. Under further investigation it turns out the retaining ring holding the switch board in is coming lose. This keeps happening to my Wf-504B as well as a similar problem popping up with my new WF-501B. While the WF-501B could be fixed with a dab of solder... the other two can not.
This leads me to once again to hounding the very knowledgeable people who make up this forum. The question I ask is thus: is there an easy way / fix to insure that the connection between tail-cap circuit board and circuit board retaining ring remain constant without the retaining ring unscrewing? I am not sure why this problem keeps occurring but my theory is that because I am left handed something about the way I push my torches buttons () causes their internals to unwind.
I ran into the same issue after removing the lanyard holder from my TrustFire X9. The retaining ring screws into the tailcap a bit loosely and, missing the lanyard holder, the tailcap screws to the battery tube far enough for the tube end to reach and press against the ring. Upon unscrewing the tailcap, the tube end holds onto the ring, loosening it.
I resolved the issue by installing an o-ring in place of the lanyard holder. That stops the tailcap from going on too far. I thought about slightly deforming one or two of the bottom windings inside the tailcap to get more friction, but haven't done that yet, as I may need to take the tailcap apart when I replace the driver.
Given the tool-gripping arrangement for unscrewing the retainer ring (two shallow holes in soft aluminium), I'd stay away from the red (strong/permanent) thread lockers.
Tailcap switches need replacing, sometimes.
Moreover, in an X9, the conductive path between retainer ring and tailcap body should be mantained.
Thanks for the suggestions guys. The Loctite Thread-lock stuff sounds perfect, I will see if I can find it here in NZ otherwise I will hunt down some nail-polish. Cheers
EDIT: Ended up adding a dab of solder to outside ring of the switchboard (opposite side of switch) so that the solder contacts the bare aluminum of the torch tail cap. Seams to be contacting well, and due to the placement of the solder even if the retaining ring unscrews contact should be kept. Also added a blob to the underside of the driver board so it can use flattop cells. This prevents me from using overly long cells but is only temporary anyway as I will replace the driver with a KD 8 AMC7135 one some day soon. Then I will have a proper look about finding more space in the tail cap and coming up with something a little more elegant.
) causes their internals to unwind. 