Good In A Pinch: The Physics Of Crimped Connections

February 9, 2017 by 125 Comments

I had a friend who was an electronics assembly tech for a big defense contractor. He was a production floor guy who had a chip on his shoulder for the engineers with their fancy book-learnin’ who couldn’t figure out the simplest problems. He claimed that one assembly wasn’t passing QC and a bunch of the guys in ties couldn’t figure it out. He sidled up to assess the situation and delivered his two-word diagnosis: “Bad crimp.” The dodgy connector was re-worked and the assembly passed, much to the chagrin of the guys in the short-sleeved shirts.

Aside from the object lesson in experience sometimes trumping education, I always wondered about that “bad crimp” proclamation. What could go wrong with a crimp to so subtly futz with a circuit that engineers were baffled? How is it that we can rely on such a simple technology to wire up so much of the modern world? What exactly is going on inside a crimped connection anyway?

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How To Properly Crimp Electronics Connectors

April 7, 2015 by 51 Comments

Putting crimp connectors on wires is one of the most tedious things you’ll do. It’s not easy, either, unless you have some practice. Before you start digging in to a pile of connectors, crimp terminals, and wire, it’s a good idea to know what you’re getting into and Gogo:tronics has a great tutorial on how to crimp electronics connectors.

Crimping connectors onto wires requires the right tool, and the most important for this task is – surprise – the crimping pliers. These pliers press the crimping wings of the connector into each other, a task made much easier on the non-ratcheting pliers if you use a rubber band to hold the jaws of the crimping pliers open just enough to hold a crimp connector.

The general theory for crimping all types of connectors is to strip a little bit of insulation off the wire. Then, put the connector into a suitably sized space in the jaws, insert the wire, and crimp it down. For non-ratcheting pliers, it’s suggested the connector be re-crimped with the next smallest hole in the jaws.

There are a few connector-specific tips for the most common connector types, too. Dupont connectors – those flat, black connectors with a 0.1″ pitch – go together like you think they would, but for larger connectors – VH and XH-style – it’s important to use the right wire gauge and not to squish the square female part of the connector.

Is That Ancient Reel Of PLA Any Good?

February 10, 2026 by 48 Comments

When it comes to knowledge there are things you know as facts because you have experienced them yourself or had them verified by a reputable source, and there are things that you know because they are common knowledge but unverified. The former are facts, such as that a 100mm cube of water contains a litre of the stuff, while the latter are received opinions, such as the belief among Americans that British people have poor dental care. The first is a verifiable fact, while the second is subjective.

In our line there are similar received opinions, and one of them is that you shouldn’t print with old 3D printing filament because it will ruin the quality of your print. This is one I can now verify for myself, because I was recently given a part roll of blue PLA from a hackerspace, that’s over a decade old. It’s not been stored in a special environment, instead it’s survived a run of dodgy hackerspace premises with all the heat and humidity that’s normal in a slightly damp country. How will it print?

It Ain’t Stringy

In the first instance, looking at the filament, it looks like any other filament. No fading of the colour, no cracking, if I didn’t know its age it could have been opened within the last few weeks. It loads into the printer, a Prusa Mini, fine, it’s not brittle, and I’m ready to print a Benchy.

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The big white thing is is the CO2 exhaust bag.

Liquid CO2 For Grid Scale Energy Storage Isn’t Just Hot Air

January 2, 2026 by 129 Comments

There’s folk wisdom in just about every culture that teaches about renewable energy — things like “make hay while the sun shines”. But as an industrial culture, we want to make hay 24/7 and not be at the whims of some capricious weather god! Alas, renewable energy puts a crimp in that. Once again, energy supplies are slowly becoming tied to the sun and the wind.

Since “Make compute while the wind blows” doesn’t have a great ring to it, clearly our civilization needs to come up with some grid-scale storage. Over in Sardinia they’re testing an idea that sounds like hot air, but isn’t — because the working gas is CO2. 

The principle is simple: when power is available, carbon dioxide is compressed, cooled, and liquefied into pressure vessels as happens at millions of industrial facilities worldwide every day. When power is required, the compressed CO2 can be run through a turbine to generate sweet, sweet electricity. Since venting tonnes of CO2 into the atmosphere is kind of the thing we’re trying to avoid with this whole rigmarole, the greenhouse gas slash working fluid is stored in a giant bag. It sits, waiting for the next charge cycle, like the world’s heaviest and saddest dirigible. In the test project in Sardinia — backed by Google, amongst others — the gas bag holds 2000 tonnes and can produce 20 megawatts of power for up-to 10 hours.

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Wiring Up The Railway, All The Live-Long Day

November 21, 2025 by 20 Comments

For those of you who haven’t spent time in North America around this time of year, you may be unaware of two things: one, the obligatory non-stop loop of “All I Want For Christmas Is You” retail workers are subjected to starting November first, and two: there is a strong cultural association between Christmastime and model railroading that may not exist elsewhere. That may down to childhood memories of when we got our first trainsets, or an excellent postwar marketing campaign by Lionel. Either way, now that Mariah Carey is blaring, we’re thinking about our holiday track layouts. Which makes this long presentation on Wiring for Small Layouts by [Chicago Crossing Model Railroad] quite timely.

There are actually three videos in this little course; the first focuses mostly on the tools and hardware used for DCC wiring (that’s Digital Command Control), which will be of less interest to our readers– most of you are well aware how to perform a lineman’s splice, crimp connectors onto a wire, and use terminal blocks.

The second two videos are actually about wiring, in the sense of routing all the wires needed for a modern layout– which is a lot more than “plug the rheostat into the tracks in one spot” that our first Lionel boxed set needed. No, for the different accessories there are multiple busses at 5V, 12V and 24V along with DCC that need to be considered. Unsurprisingly enough given those voltages, he starts with an ATX power supply and breaks out from there.

Even if you’re not into model railroading, you might learn something from these videos if you haven’t done many projects with multiple busses and wire runs before. It’s far, far too easy to end up with a rats nest of wires, be they DCC, I2C or otherwise. A little planning can save some big headaches down the line, and if this is a new skill for you [Chicago Crossing Model Railroad] provides a good starting point for that planning. Just skip ahead a couple minutes for him to actually start talking if you don’t want the musical cliff notes montage at the start of the videos.

If you don’t have any model trains, don’t worry, you can 3D print them.  Lack of room isn’t really an excuse.

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Building A (Not Very) Portable Xbox

September 21, 2025 by 24 Comments

Modern handheld game consoles are impressive feats of engineering, featuring full fledged computers in near pocket-sized packages. So what happens if you take an original Xbox and sprinkle on some modern electronics and create a handheld? Well, if you’re [James] of James Channel, you end up with this sandwich of PCBs held together with hot glue and duck tape. 

The first order of miniaturization in this Xbox was replacing the hard drive. Because a CompactFlash card uses parallel ATA, that could be a simple drop in replacement. However, the Xbox locks the hard drive to the system requiring a mod chip for the CF card to work. Fortunately, the sacrificial Xbox came with a mod chip installed. After using an arcade machine to flash the card and copy over the contents of the drive, the CF card install was a breeze. 

For the screen and batteries, a portable DVD player that had remained unused since 2006 was repurposed. The battery cells were rather unhappy, but managed to get resurrected with some careful charging. As it turns out, the iPod 30 pin connector inside the portable screen contains an S-Video line. By tapping into that and adding in some power management for the batteries, the Xbox became a pile of PCBs that could maybe be taken places.

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Give Your Twist Connections Some Strength

September 9, 2025 by 44 Comments

We’ve all done it at some time — made an electrical connection by twisting together the bare ends of some wires. It’s quick, and easy, but because of how little force required to part it, not terribly reliable. This is why electrical connectors from terminal blocks to crimp connectors and everything else in between exist, to make a more robust join.

But what if there was a way to make your twist connections stronger? [Ibanis Sorenzo] may have the answer, in the form of an ingenious 3D printed clamp system to hold everything in place. It’s claimed to result in a join stronger than the wire itself.

The operation is simple enough, a spring clamp encloses the join, and a threaded outer piece screws over it to clamp it all together. There’s a pair of 3D printable tools to aid assembly, and a range of different sizes to fit different wires. It looks well-thought-out and practical, so perhaps it could be a useful tool in your armoury. We can see in particular that for those moments when you don’t have the right connectors to hand, a quick 3D print could save the say.

A few years ago we evaluated a set of different ways to make crimp connections. It would be interesting to subject this connection to a similar test. Meanwhile you can see a comprehensive description in the video below the break.

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