18 Aug
2006
18 Aug
'06
11:53 a.m.
Billy Pettit wrote:
Don <THX1138 at dakotacom.net> wrote:
Yup. I have a nice assortment of similar telco tools (including
armature adusters, etc.). Unfortunately, MaBell used heavy
gauge wire on most of those things --whereas most of the
wirewrapped devices I have worked with used 30AWG kynar
or teflon wire.
I also have a really neat pair of needle nose that have the
jaws machined to act like no-niks. You learn early on that
these are *only* to be used for stripping wire or holding wire
and NEVER to carry any "load"! :-/
(I wish I could find a commercial source for these)
TIP: An embroidery hook works wonders for
fishing wirewrap wires
out of a nest without too much damage! ;-) (but you have to
find the right size hook to ensure a "good grab" on the wire)
For those of us who go back to the dawn, there was the spring hook, a
beautifully functional tool used on the relay machines. They worked great
on the thick wire mats. I still have all of mine and even today find the
spring hook to be one of the most useful tools around the shop. Another tool I found useful was a jewelers device to
hold rings for
soldering. It looks like a pair of tweezers with the ends bent out so they
can't touch. You squeeze it, stick it in the wire mat, and release. The
tension holds the wires apart. We made a bunch of copies using piano wire
and put shrink tubing over the ends.
You can use the pliers that are used for *outer* clip rings
to do this -- with a rubber band around the handles. (i.e. the jaws
OPEN as the handles are drawn together).
If you get a chance, look at the 6600 or 7600 in the
Museum. Seymour loved
those dense wire mats - he used wire lengths to tune his systems. If you
worked on one of his machines, you spent a significant part of your working
hours buried in wire up to your forearms.
The same was true in the "tester" -- you had to resolve time to
1ns resolution so lots of wirelength issues, loading devices
to get the right transition times, etc.
For a one-of-a-kind machine (I think we *might* have built
two!), it wasn't too bad. But, I would dread having to do this
in a production environment!
The worst was the Cyber 170 machines. They were
twisted pair 30 gauge wire
mats. If you weren't careful, the pins bent and touched. And there was
what we called "tingles". The broken piece off the end of a wire would
disappear into the wire mat and eventually short two pins out. Even more
fun, if you were tuning clocks, the power was on, so you could watch the
path of the tingle by the little sparks. Always happened on a Friday night,
of course.
If you only *partially* unwrap the wire (i.e. take the "tension"
out of the coil) and then deliberately *break* the wire where
it connects to the insulated portion (this is where the wire
typically *wants* to break) you can fish out the insulated
tail and then carefully lift the expanded wire coil off of the
WW pin (using the fancy needlenose pliers mentioned above).
OTOH, if you *pulled* on the insulated portion before breaking
the wire *or* tried to pull the "coil" (tingle?) off, you were
almost guarantees to end up with tiny bits of bare wire
suspended in the ratsnest! :(
One of the worst nightmares I worked on was a machine
that the engineers
working on, had set their coffee cups on top of the cabinet and forgot about
them. This was before the styrofoam cups, just waxed paper. It soaked
through and dumped the coffee down into the wire mat. We tried for a few
days to fix it but finally had to scrap the entire chassis. Per the Peter
Principle, the chief suspect was later promoted to be my manager.
Ha! And later ran the company, no doubt! :-(