Back in the 70s when I started getting interested in electronics, tons of magazines catered to the hobbyist market. Popular Electronics was my favorite, and I think I remember the advertisements more than anything, probably because they outnumbered articles by a large margin. Looking back, it seemed like a lot of ad space was sold to companies hawking the tools and materials needed for wire wrapping, which was very popular for prototyping in the days before solderless breadboards were readily available. I remember beauty shots of neat rows of small, gold posts, with stripped wires wrapped evenly around them.

To the budding hobbyist, wire wrapping looked like the skill to have. With a huge selection of posts, terminals, and sockets for ICs and discrete components, as well as a wide range of manual and powered wrapping tools, it seemed like you could build anything with wire wrapping. But fast forward just a decade or so, and wire wrapping seemed to drop out of favor. And today — well, does anyone even wire wrap anymore?

Where Inventions Were Born

Almost everything we take for granted in the modern world can trace at least some of its lineage back to Bell Labs, the invention factory in the New Jersey suburbs, and wire wrapping is no exception. While wire wrapping may not have been invented there — a good argument can be made that it started in the previous century with telegraph linesmen splicing and securing wires in the field — the needs of the telephone industry, particularly in the central office, propelled the development of tools and techniques that would make connections easier. Bell Labs and Western Electric, the manufacturing arm of AT&T, would perfect wire wrapping in the mid-1950s.

The idea behind wire wrapped connections is simple — make a tight, metal-to-metal connection that’s electrically and mechanically solid, and do it as rapidly as possible. Soldering seems like it would make more sense electrically and mechanically, but it takes time and skill to execute properly, and introduces problems of its own. Wire wrapping, on the other hand, allowed telco techs to make hundreds of connections quickly, with simple tools, and in tight spaces.

Specifics varied between applications, but the basics include terminals in the form of posts with a square cross-section and insulated solid wire. Insulation was stripped to a specified length, with care taken to avoid nicking the conductor within. The stripped wire was loaded into the metal bit of a wrapping tool, which was then placed over the post. A few quick turns of the bit, either with hand or electric power, wrapped the wire snugly around the post for about five complete turns and completed the connection.

Bil Herd did a great piece on the tools and techniques of wire wrapping a few years back, and this video shows what’s involved in making wire wraps:

Where Is It Now?

So what made wrapped connections so great? Part of it was the electrical and mechanical properties of the connection. A properly wrapped post would have at least one turn of the insulated part of the wire wrapped around the post, providing a degree of mechanical support that kept the conductor from breaking if the assembly were subjected to vibration. There’s also the benefits of the square post corners cutting into the round conductor twenty or so times along the wrap. Such connections are gas-tight, so oxygen is excluded from the mating surfaces and oxidation inside the joint is avoided. This also lets the wire and post form a cold weld, significantly reducing the resistance of the connection.

And yet we see precious little wire wrapping these days, at least judging by your tips and Hackaday.io projects. Why is that? Is it the rise of super cheap PCBs and the tools to design them quickly? Is it the increased availability and use of SMD components and the tools to properly handle them? Maybe wire wrapping is mainly used in the industry today for prototyping and has just lost favor in at the hobby end of the market? Or perhaps my perception is wrong, and wire wrapping is alive and well across the board, in which case maybe I should invest in some Kynar and a squeeze tool and get wrapping.

What’s your experience with wire wrapping? Sound off in the comments below.

Next time you’re renovating and need to run some cables around corners in you walls, save yourself some frustration by building [izzy swan]’s corner drilling rig. It’s something akin to a custom tunnel boring machine but on a small scale.

Starting with a piece of steel, [izzy] traced and cut out a 90 degree curve with an attached arm that will allow it to rotate from a central block. He then grabs a random drill bit and attaches it to a flex shaft which is secured to the leading point of the steel curve. To complete the handy setup the entire rig is bolted to a block that will clamp over the corner stock.

As it stands, it takes some elbow grease to get the drill through, but it’s not a purpose built setup. On a second demonstration, the flex shaft breaks, but the idea is there. Now, [izzy] advises that this is most easily accomplished when re-framing walls with no drywall obstructing your drill, but the concept for this rig could nonetheless prove handy for welding, grinding, and so forth along any angled curve.

If instead you want to push your carpentry skills to their limits, build a wooden Vespa.

[Thanks for the tip, Itay Ramot!]

This drill press was built to drill through-hole printed circuit boards. [Rhys Goodwin] didn’t want to shell out for new equipment, so he dug through his scraps to see what he could accomplish. He already had the power drill, and there was no shortage of wood and fasteners. Once he had a mounting platform for the power tool he grabbed a pair of slides from and old rack-mount server rail. This provides smooth and precise movement, along with a tension sprint to keep the rig elevated above the work surface. Turns out the only thing he didn’t already have was the mini-chuck for gripping the 0.8 mm drill bit.

It seems as if [Rhys] is hacking up a storm lately. This drill press is for use with his Inkjet/Toner PCB process from two weeks ago. We also covered his bulk component salvaging system in Sunday’s Links post.

We’re not sure how we missed [Jack Eisenmann’s] 4 bit TTL CPU when we were tipped off the first time, but we’re glad it was sent in again for us to feature it.

41 different ICs (mostly TTL) come together to comprise the DUO 128 Elite. While the architecture is a little different than what we’ve seen before, using “nyckles”, the DUO 128 Elite still works perfectly. Catch a video of some example programs, including pong, after the divide.

[Thanks Marc G-C]

[youtube http://www.youtube.com/watch?v=4IxWSvlcP3c%5D

If you are curious about reading all the bits on a DVD, [tmbinc] has devised a hardware hack that uses a Pioneer DVD drive with leads soldered onto it and a Cypress FX2 microcontroller board to grab the flow of bits and push them over USB2.0. My favorite part of this tutorial is when you slow the spinning DVD down very slightly with your finger with a scope hooked up over what you believe to be the raw data stream from the disk. If the data rate slows when you physically slow down the disk, you probably are grabbing data from the correct pin. [tmbinc] even put together a software tool to process the resulting raw DVD data.