In article ,
clifto wrote:

Smitty Two wrote:
clifto wrote:
That said, the contact between the end cap and body is still the worst
connection on the whole flashlight.

Not to be too pedantic, here, but could you elaborate? What's so bad
about it? The only thing I can think of is maybe some looseness in the
thread, but given the total thread area and the trivial current carrying
requirements, it seems fine. I've never had any trouble with any size of
maglite.

With my two, and colleagues' dozen or so, I've had to constantly clean and
lubricate the screw threads on both the end cap and body. Second worst
contact is between the press-in spring and the end cap, and that one
needs constant attention as well. It's not looseness. I haven't figured
out exactly what the problem is; I only know that cleaning and lubing
the end cap works.

With yours turned on, try unscrewing the end cap a full turn. Observe
that there should be an awful lot of actual contact area between the
few complete turns of spiral screw thread on the end cap and the same
on the body. There should be at least 1/2 a square millimeter touching
at some point along all that. Yet, as you'll probably see, the light
goes on and off as you turn. If something weren't wrong there, I would
believe it would be really difficult to be able to break contact between
the battery negative end and the body of the light; it should be difficult.
The only units I've ever seen that would remain lit were brand new.
Even when my latest was one week old, the light would go on and off
when I loosened the end cap.

OK, finally got back to this. I have four AA mini-mags and one AAA
mini-mag. None of them exhibit this symptom. They all stay lit
consistently until the very last thread disengages. I rely on these
flashlights frequently and have never, ever, had any kind of reliability
issue, and have never had to do any maintenance to them.

I also checked my two 3-cell D-cell mags. They have anodized threads and
a non-anodized contact circle between the end cap and the body, so they
*do* need to be snug to work.

Apparently you and your colleagues are working in some sort of corrosive
environment, or perhaps the lube you're using is corrosive to aluminum?