On Thu, 15 Apr 2021 07:36:54 +0100, alan_m
wrote:

On 14/04/2021 21:11, T i m wrote:
On Wed, 14 Apr 2021 19:31:40 +0100, Mark Carver
wrote:

snip

In 37 years working in the industry, I've only ever known a couple to
fail in service. And probably less than 20 or so to be a 'duffer' when made.

I've sent plenty fail in use or when made but that could be down to
the wrong technique, poor tools or cheap components (or a mix of
each).


40+ years ago the main problem where I worked was the different centre
pin diameter for 50 and 75 BNCs and both types were used in the same
workshop/lab. Sockets could become unreliable when previously used with
the "wrong" BNC mating half.

Stretching the 'split' socket I'm guessing?

Sods law said all the fly lead cables were
black and for some people any cable would do!

Quite, even when they were too short and caused network instabilities
(as I saw in person on a mates Co network).

The only time I managed to pull a solder / bolt up BNC connector off a
(RG58) cable was when trying to extract a cable from behind a very
heavy equipment cabinet and I had to pull *very* hard. Even after
that, I was able to recover the pin and the connector and re-unite
them on a new cable. ;-)

Maybe it's because I'm reasonably adept at soldering and mechanics
that with my extra glasses on and sufficient practice (knowing the
lengths of the different sections) I can make a 100% reliable /
predictable BNC connection where even if it seems to go perfectly, I
don't really trust crimps?

After 5+ years of fairly regular use and millions of movements, one of
the wires broke off the connector on the extruder stepper motor on my
3D printer the other day.

The extruder goes left and right ~200 mm (and up/down 150mm but
slower) and this cable came directly off the fine JST plug, over the
top frame of the printer and down to the controller and was completely
unsupported, meaning all the load generated by this constant left /
right movement was managed by the wire in the connector.

When replacing it, I noticed it was something I must have soldered up
*temporarily* and it had fractured on the wire just after the joint
(as you would expect). I have taped the replacement cable down to the
motor so there is no longer any strain on the joint itself. ;-)

Cheers, T i m