Every person who reads these pages is likely to have encountered a neodymium magnet. Most of us interact with them on a daily basis, so it is easy to assume that the process for their manufacture must be simple since they are everywhere. That is not the case, and there is value in knowing how the magnets are manufactured so that the next time you pick one up or put a reminder on the fridge you can appreciate the labor that goes into one.
[Michael Brand] writes the Super Magnet Man blog and he walks us through the high-level steps of neodymium magnet production. It would be a flat-out lie to say it was easy, but you’ll learn what goes into them and why you don’t want to lick a broken hard-drive magnet and why it will turn to powder in your mouth. Neodymium magnets are probably unlikely to be produced at this level in a garage lab, but we would love to be proved wrong.
Oxford is a city world-famous for its university, and is a must-see stop on the itinerary of many a tourist to the United Kingdom. It features mediaeval architecture, unspoilt meadows, two idylic rivers, and a car plant. That’s the part the guide books don’t tell you, if you drive a BMW Mini there is every chance that it was built in a shiny new factory on the outskirts of the historic tourist destination.
A 1930s Morris Ten Series II. Humber79 [CC BY-SA 3.0].The origins of the Mini factory lie over the road on a site that now houses a science park but was once the location of the Morris Motors plant, at one time Britain’s largest carmaker. In the 1930s they featured in a British Pathé documentary film which we’ve placed below the break, part of a series on industry in which the production of an internal combustion engine was examined in great detail. The music and narration is charmingly of its time, but the film itself is not only a fascinating look inside a factory of over eight decades ago, but also an insight into engine manufacture that remains relevant today even if the engine itself bears little resemblance to the lump in your motor today.
Morris produced a range of run-of-the-mill saloon cars in this period, and their typical power unit was one of the four-cylinder engines from the film. It’s a sidevalve design with a three-bearing crank, and it lacks innovations such as bore liners. The metallurgy and lubrication in these engines was not to the same standard as an engine of today, so a prewar Morris owner would not have expected to see the same longevity you’d expect from your daily.
Mere weeks ago, the United States announced it was set to impose a 25% tariff on over 800 categories of Chinese goods. These tariffs include nearly every component that goes into the manufacture of any piece of electronic hardware, from resistors to capacitors, semiconductors to microcontrollers, and even the raw components that are turned into printed circuit boards. These tariffs will increase the cost of materials for electronics, even if those electronics are ultimately manufactured in the United States because suppliers and subcontractors must source their materials from somewhere, and more often than not, that place is China.
In the world of musical synthesizers, there is no bigger name than Moog. The company was founded in the 1950s manufacturing theremins, and in the 1960s, production moved to synthesizers. The famous Minimoog, launched in 1970, has been featured on tens of thousands of albums. Modern music simply wouldn’t exist without Moog synthesizers. After a buyout, mismanagement, and bankruptcy in the 1980s, the company was reborn in the early 2000s, moved into a beautiful factory in Asheville, North Carolina, and has gone on to produce some of the most popular synthesizers ever made.
The company’s statement says these new tariffs will, ‘immediately and drastically increase the cost of building our instruments, and have the very real potential of forcing us to lay off workers and could.. require us to move some, if not all, of our manufacturing overseas’. In a statement on Twitter, Moog says they source half their PCBs and a majority of other materials domestically, already paying up to 30% more than if the PCBs were sourced from China. However, because the raw materials for PCB manufacture are also sourced from China, board manufacturers for Moog’s synths will be forced to pass along the 25% tariff to their customers.
The threat of Moog being forced to move production of their instruments to China is real. Like cell phones, laptops, and other finished goods, synthesizers are not covered by the new tariff. As noted by Bunnie Huang, these tariffs have the perverse incentive of shifting US manufacturing jobs to China.
These tariffs have been a point of contention for the electronics and engineering communities. Anyone can easily pull up the distributor information from a Mouser or Digikey order and find the country of origin for an entire Bill of Materials. It has already been confirmed that most of the FR4 and other raw components that go into manufacturing PCBs in the United States come from Chinese suppliers. These items can be cross-referenced with the list of items that will be subject to a 25% tariff next week. Manufacturing electronics in the United States, even if you get your PCBs from US manufacturers and parts from US suppliers, will cost more in just a few short days.
Look around yourself right now and chances are pretty good that you’ll quickly lay eyes on a zipper. Zippers are incredibly commonplace artifacts, a commodity item produced by the mile that we rarely give a second thought to until they break or get stuck. But zippers are a fairly modern convenience, and the story of their invention is one that shows even the best ideas can be delayed by overly complicated designs and lack of a practical method for manufacturing.
Try and Try Again
US Patent #504,307. One of the many iterations of Judson’s design. Like the others, it didn’t work.
Ideas for fasteners to replace buttons and laces have been kicking around since the mid-19th century. The first patent for a zipper-like fastener was issued to Elias Howe, inventor of the sewing machine. Though he was no slouch at engineering intricate mechanisms, Howe was never able to make his “Automatic, Continuous Clothing Closure” a workable product, and Howe shifted his inventive energies to other projects.
The world would wait another forty years for further development of a hookless fastener, when a Chicago-born inventor of little prior success named Whitcomb Judson began work on a “Clasp Locker or Unlocker.” Intended for the shoe and boot market, Judson’s device has all the recognizable parts of a modern zipper — rows of interlocking teeth with a slide mechanism to mesh and unmesh the two sides. The device was debuted at the Chicago World’s Fair in 1893 and was met with almost no commercial interest.
Judson went through several iterations of designs for his clasp locker, looking for the right combination of ideas that would result in a workable fastener that was easy enough to manufacture profitably. He lined up backers, formed a company, and marketed various versions of his improved products. But everything he tried seemed to have one or more serious drawbacks. When his fasteners were used in shoes, unexpected failure was a mere inconvenience. If a fastener on a lady’s dress opened unexpectedly, it could have been a social catastrophe. Coupled with a price tag that was exorbitantly high to cover the manual labor needed to assemble them, almost every version of Judson’s invention flopped.
It would take another decade, a change of company name, a cross-country move, and the hiring of a bright young engineer before the world would have what we would recognize as the first modern zipper. Judson hired Gideon Sundback in 1901, and by 1913 he was head designer at the Fastener Manufacturing and Machine Company, newly relocated to Meadville, Pennsylvania after a stop in Hoboken, New Jersey. Sundback’s design called for rows of identical teeth with cups on the underside and nibs on the upper, set on fabric tapes. A slide with a Y-shaped channel bent the tapes to open the gap between teeth, allowing the cups to nest on the nibs and mesh the teeth together strongly.
Sundback’s design had significant advantages over any of Judson’s attempts. First, it worked, and it was reliable enough to start quickly making inroads into fashionable apparel beyond its initial marketing toward more utilitarian products like tobacco pouches. Secondly, and perhaps more importantly, Sundback invented machinery that could make hundreds of feet of the fasteners in a day. This gave the invention an economy of scale that none of Judson’s fasteners could ever have achieved.
The machinery that Sundback invented to make his “Separable Fastener” has been much improved since the early 1900s, but the current process still looks similar, at least for metal zippers. Stringers, which are the fabric tapes with teeth attached, are formed in a continuous process by a multi-step punching and crimping machine. For metal stringers, a coil of flat metal is fed into a punch and die to form hollow scoops. The strip is then punched again to form a Y-shape around the scoop and cut it free from the web. The legs of the Y straddle the edge of the fabric tape, and a set of dies then crimps the legs to the tape. A modern zipper machine can make stringers at a rate of 2000 teeth per minute.
Plastic zippers are common these days, too, and manufacturing methods vary by zipper style. One method has the fabric tapes squeezed between the halves of a die while teeth are injection molded around the tape to form two parallel stringers. A sprue connected the stringers by the teeth breaks free after molding, and the completed stringers are assembled later.
Zippers have come a long way since Sundback’s first successful design, with manufacturing improvements that have eliminated many of the manual operations once required. Specialized zippers have made it from the depths of the oceans to the surface of the Moon, and chances are pretty good that if we ever get to Mars, one way or another, zippers will go with us.
If you’re looking for a get-rich-quick scheme, you can scratch “Doing small-scale manufacturing of ultralight aircraft” off your list right now. Turns out there’s no money in it. At least, not enough money that you can outsource production of all the parts. Not even enough to setup a huge shop full of customized machining tools when you realize you have to make the stuff yourself. No, this sounds like one of those “labors of love” we always hear so much about.
So how does one do in-house manufacturing of aircraft with a bare minimum of tools? Well, since you’re reading this on Hackaday you can probably guess that you’ve got to come up with something a bit unorthodox. When [Brian Carpenter] of Rainbow Aviation needed a very specific die to bend a component for their aircraft, he decided to try designing and 3D printing one himself.
Printing a die on the Zortrax M200
He reasoned that since he had made quick and dirty dies out of wood in the past, that a 3D printed one should work for at least a few bends before falling apart. He even planned to use JB Weld to fill in the parts of the printed die which he assumed would start cracking and breaking off after he put it through a few cycles. But even after bending hundreds of parts, wear on the dies appears to be nearly non-existent. As an added bonus, the printed plastic dies don’t mar the aluminum pieces they are bending like the steel dies do.
So what’s the secret to printing a die that can bend hundreds of pieces of aluminum on a 20 ton brake without wearing down? As it turns out…not a whole lot. [Brian] attributes the success of this experiment to designing the die with sufficiently accurate tolerances and having so high of an infill that it may as well be solid plastic.
In fact, the 3D printed die worked out so well that they’ve now expanded the idea to a cheap Harbor Freight brake. Before this tool was going more or less unused as it didn’t have features they needed for the production of their parts, namely a radius die or backstop. But by 3D printing these components [Brian] was able to put the tool back to work.
Television has been around for a long time, but what we point to and call a TV these days is a completely different object from what consumers first fell in love with. This video of RCA factory tours from the 1950s drives home how foreign the old designs are to modern eyes.
Right from the start the apparent chaos of the circuitry is mindboggling, with some components on circuit boards but many being wired point-to-point. The narrator even makes comments on the “new technique for making electrical connections” that uses a wire wrapping gun. The claim is that this is cleaner, faster, and neater than soldering. ([Bil Herd] might agree.) Not all of the methods are lost in today’s manufacturing though. The hand-stuffing and wave soldering of PCBs is still used on lower-cost goods, and frequently with power supplies (at least the ones where space isn’t at a premium).
It’s no surprise when talking about 60+ year-old-designs that these were tube televisions. But this goes beyond the Cathode Ray Tube (CRT) that generates the picture. They are using vacuum tubes, and a good portion of the video delves into the manufacture and testing of them. You’ll get a glimpse of this at 3:20, but what you really want to see is the automated testing machine at 4:30. Each tube travels along a specialized conveyor where the testing goes so far as to give a few automated whacks from corks on the ends of actuators. As the tube gauntlet progresses, we see the “aging” process (around 6:00) when each tube is run at 3-4 times the rated filament voltages. Wild!
There’s a segment detailing the manufacture of the CRT tubes as well, although these color tubes don’t seem to be for the model of TV being followed during the rest of the films. At about 7:07 they call them “Color Kinescopes”, an early name for RCA’s CRT technology.
During the factory tours we get the overwhelming feeling that this manufacturing is more related to automotive than modern electronic. These were the days when televisions (and radios) were more like pieces of furniture, and seeing the hulking chassis transported by hanging conveyors is just one part of it. The enclosure plant is churning out legions of identical wooden consoles. This begins at 11:55 and the automation shown is very similar to what we’d expect to see today. It seems woodworking efficiency was already a solved problem in the ’50s.
Judging by the popularity of “How It’s Made” and other shows of the genre, watching stuff being made is a real crowd pleaser. [Jonathan Oxer] from SuperHouse is not immune to the charms of a factory tour, so he went all the way to China to visit the factory where Sonoff IoT devices are made, and his video reveals a lot about the state of electronics manufacturing.
Test jig for six units at once
For those interested only in how Sonoff devices are manufactured, skip ahead to about the 7:30 mark. But fair warning — you’ll miss a fascinating discussion of how Shenzhen rose from a sleepy fishing village of 25,000 people to the booming electronics mecca of 25 million that it is today. With growth supercharged by its designation as a Special Economic Zone in the 1980s, Shenzhen is now home to thousands of electronics concerns, including ITEAD, the manufacturers of the Sonoff brand. [Jonathan]’s tour of Shenzhen includes a trip through the famed electronics markets where literally everything needed to build anything can be found.
At the ITEAD factory, [Jonathan] walks the Sonoff assembly line showing off an amazingly low-tech process. Aside from the army of pick and places robots and the reflow and wave soldering lines, Sonoff devices are basically handmade by a small army of workers. We lost count of the people working on final assembly, testing, and packaging, but suffice it to say that it’ll be a while before robots displace human workers in electronic assembly, at least in China.
We found [Jonathan]’s video fascinating and well worth watching. If you’re interested in Sonoff’s ESP8266 offerings, check out our coverage of reverse engineering them. Or, if Shenzhen is more your thing, [Akiba]’s whirlwind tour from the 2016 Superconference will get you started.
![A 1930s Morris Ten Series II. Humber79 [CC BY-SA 3.0].](https://hackaday.com/wp-content/uploads/2018/05/morris10080809e.jpg)
Right from the start the apparent chaos of the circuitry is mindboggling, with some components on circuit boards but many being wired point-to-point. The narrator even makes comments on the “new technique for making electrical connections” that uses a wire wrapping gun. The claim is that this is cleaner, faster, and neater than soldering. ([Bil Herd] 
