Lorentz Cannon Fires Lightning

February 6, 2025 by Al Williams 28 Comments

[Editor’s note: This video disappeared, but it has been archived here. We’re leaving the original links as-were in case they come back up.]

The aptly named [LightingOnDemand] has created a Lorentz cannon that can fire a lightning bolt. Honestly, as you can see in the video below, it looks like something from a bad 1950s science fiction movie. The inspiration was researchers using rockets trailing thin wires to attract lightning.

How does the tiny wire carry that much juice? It doesn’t, really. The wire vaporizes into plasma, and if the pulse is fast enough, the Lorentz force hold the plasma together. The rest is non-trivial high-voltage engineering.

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How Do We Deal With Microplastics In The Ocean?

February 6, 2025 by Lewin Day 47 Comments

Like the lead paint and asbestos of decades past, microplastics are the new awful contaminant that we really ought to do something about. They’re particularly abundant in the aquatic environment, and that’s not a good thing. While we’ve all seen heartbreaking photos of beaches strewn with water bottles and fishing nets, it’s the invisible threat that keeps environmentalists up at night. We’re talking about microplastics – those tiny fragments that are quietly infiltrating every corner of our oceans.

We’ve dumped billions of tons of plastic waste into our environment, and all that waste breaks down into increasingly smaller particles that never truly disappear. Now, scientists are turning to an unexpected solution to clean up this pollution with the aid of seashells and plants.

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Lorem Ipsum 36? Dolor Sit Amet Keyboard!

February 6, 2025 by Kristina Panos 10 Comments

You know, it’s a tale as old as custom mechanical keyboards. [penkia] couldn’t find any PCBs with 36 keys and Gateron low-profile switch footprints, so they made their own and called it the LoremIpsum36. Isn’t it lovely?

This baby runs on an RP2040, which sits flush as can be in a cutout in the PCB. This maneuver, along with the LP switches in hard-to-find SK-33 sockets results in quite the thin board.

[penkia] says that despite using a 3 mm tray for added rigidity, the entire thing is thinner than the Nuphy Air60 v2, which is just over half an inch (13.9 mm) thick. For keycaps, [penkia] has used both XVX profile and FKcaps’ LPF.

And yeah, that area in the middle is crying out for something; maybe a trackball or something similar. But [penkia] is satisfied with it as-is for the first version, so we are, too.

Do you like 36-key boards, but prefer curves? Check out the Lapa keyboard, which doubles as a mouse.

A Tube, The Wooden Kind

February 6, 2025 by Al Williams 21 Comments

While we aren’t heavy-duty woodworkers, we occasionally make some sawdust as part of a project, and we admire people who know how to make wood and do what they want. We were surprised when [Newton Makes] showed a wooden dowel that was quite long and was mostly hollow. The wall was thin, the hole was perfectly centered, and he claimed he did not use a drill to produce it. Check it out in the video below and see what you think.

We don’t want to spoil the surprise, but we can tell you that making something that long with a drill or even a drill press would be very difficult. The problem is that drills have runout — the bits are usually not totally centered, so the bit doesn’t spin like you think it does. Instead, it spins and rotates around a small circle.

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This Thermometer Rules!

February 5, 2025 by Jenny List 9 Comments

A PCB ruler is a common promotional item, or design exercise. Usually they have some sample outlines and holes as an aid to PCB design, but sometimes they also incorporate some circuitry. [Clovis Fritzen] has given us an ingenious example, in the form of a PCB ruler with a built-in thermometer.

This maybe doesn’t have the fancy seven segment or OLED display you were expecting though, instead it’s an ATtiny85 with a lithium cell, the minimum of components, a thermistor for measurement, and a couple of LEDs that serve as the display. These parts are interesting, because they convey the numbers by flashing. One LED is for the tens and the other the units, so count the flashes and you have it.

We like this display for its simplicity, we can see the same idea could be used in many other places.On a PCB ruler, it certainly stands apart from the usual. It has got plenty of competition though.

A picture of a stainless steel ring with a phillips screwdriver bit protruding from it sitting slightly askance atop a matching ring with a phillips head cut out like that of a screw. They are the same size so they can mesh when placed together.

Making Products For Fun And (Probably No) Profit

February 5, 2025 by Navarre Bartz 25 Comments

If you’re like most makers, you have a few product ideas kicking about, but you may not have made it all the way to production of those things. If you’re thinking about making the leap, [Simone Giertz] recently discussed all the perils and pitfalls of the process from idea to reality.

The TLDR is that there’s a big difference between making one item and making hundreds or thousands of them, which you probably already knew, but it is nice to see what sort of issues can crop up in this seemingly simple example of the Yetch Screwdriver Ring. It turns out that the metalworking skills of tool making and jewelry making rarely overlap in the contract manufacturing world.

[Giertz] also shares some of the more mundane, yet terrifying, parts of business like finally committing to bulk orders and whether it’s wise to go with intermediaries when working with suppliers overseas. She also keys us into parts of the process where things can go wrong, like how product samples typically use a different manufacturing process than bulk for practical reasons and how you need to have very specific quality control requirements not just decide if a product is good enough based on vibes.

If you’d like some more advice on making your own products, check out [Carrie Sundra]’s Supercon talk about Manufacturing on a Shoestring Budget.

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Investigating Electromagnetic Magic In Obsolete Machines

February 5, 2025 by Bryan Cockfield 15 Comments

Before the digital age, when transistors were expensive, unreliable, and/or nonexistent, engineers had to use other tricks to do things that we take for granted nowadays. Motor positioning, for example, wasn’t as straightforward as using a rotary encoder and a microcontroller. There are a few other ways of doing this, though, and [Void Electronics] walks us through an older piece of technology called a synchro (or selsyn) which uses a motor with a special set of windings to keep track of its position and even output that position on a second motor without any digital processing or microcontrollers.

Synchros are electromagnetic devices similar to transformers, where a set of windings induces a voltage on another set, but they also have a movable rotor like an electric motor. When the rotor is energized, the output windings generate voltages corresponding to the rotor’s angle, which are then transmitted to another synchro. This second device, if mechanically free to move, will align its rotor to match the first. Both devices must be powered by the same AC source to maintain phase alignment, ensuring their magnetic fields remain synchronized and their rotors stay in step.

While largely obsolete now, there are a few places where these machines are still in use. One is in places where high reliability or ruggedness is needed, such as instrumentation for airplanes or control systems or for the electric grid and its associated control infrastructure. For more information on how they work, [Al Williams] wrote a detailed article about them a few years ago.

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