Engineering

583 Articles

The Tragic Story Of The Ill-Fated Supergun

May 28, 2024 by 63 Comments

In the annals of ambitious engineering projects, few have captured the imagination and courted controversy quite like Gerald Bull’s Supergun. Bull, a Canadian artillery expert, envisioned a gun that could shoot payloads directly into orbit. In time, his ambition led him down a path that ended in both tragedy and unfinished business.

Depending on who you talk to, the Supergun was either a new and innovative space technology, or a weapon of war so dangerous, it couldn’t be allowed to exist. Ultimately, the powers that be intervened to ensure we would never find out either way.

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A thickness gauge, letter scale, push stick, and dial caliper

Measure Three Times, Design Once

May 16, 2024 by 35 Comments

Most of the Hackaday community would never wire a power supply to a circuit without knowing the expected voltage and the required current. But our mechanical design is often more bodged. We meet folks who carefully budget power to their microcontroller, sensors, and so on, but never measure the forces involved in their mechanical designs. Then they’re surprised when the motor they chose isn’t big enough for the weight of their robot.

An obstacle to being more numbers oriented is lack of basic data about the system. So, here are some simple tools for measuring dynamic properties of small mechanisms; distances, forces, velocities, accelerations, torques, and other things you haven’t thought about since college physics. If you don’t have these in your toolkit, how do you measure?

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A Slice Of Simulation, Google Sheets Style

May 15, 2024 by 9 Comments

Have you ever tried to eat one jelly bean or one potato chip? It is nearly impossible. Some of us have the same problem with hardware projects. It all started when I wrote about the old bitslice chips people used to build computers before you could easily get a whole CPU on a chip. Bitslice is basically Lego blocks that build CPUs. I have always wanted to play with technology, so when I wrote that piece, I looked on eBay to see if I could find any leftovers from this 1970-era tech. It turns out that the chips are easy to find, but I found something even better. A mint condition AM2900 evaluation board. These aren’t easy to find, so the chances that you can try one out yourself are pretty low. But I’m going to fix that, virtually speaking.

This was just the second potato chip. Programming the board, as you can see in the video below, is tedious, with lots of binary switch-flipping. To simplify things, I took another potato chip — a Google Sheet that generates the binary from a quasi-assembly language. That should have been enough, but I had to take another chip from the bag. I extended the spreadsheet to actually emulate the system. It is a terrible hack, and Google Sheets’ performance for this sort of thing could be better. But it works.

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Mining And Refining: Uranium And Plutonium

April 24, 2024 by 40 Comments

When I was a kid we used to go to a place we just called “The Book Barn.” It was pretty descriptive, as it was just a barn filled with old books. It smelled pretty much like you’d expect a barn filled with old books to smell, and it was a fantastic place to browse — all of the charm of an old library with none of the organization. On one visit I found a stack of old magazines, including a couple of Popular Mechanics from the late 1940s. The cover art always looked like pulp science fiction, with a pipe-smoking father coming home from work to his suburban home in a flying car.

But the issue that caught my eye had a cover showing a couple of rugged men in a Jeep, bouncing around the desert with a Geiger counter. “Build your own uranium detector,” the caption implored, suggesting that the next gold rush was underway and that anyone could get in on the action. The world was a much more optimistic place back then, looking forward as it was to a nuclear-powered future with electricity “too cheap to meter.” The fact that sudden death in an expanding ball of radioactive plasma was potentially the other side of that coin never seemed to matter that much; one tends to abstract away realities that are too big to comprehend.

Things are more complicated now, but uranium remains important. Not only is it needed to build new nuclear weapons and maintain the existing stockpile, it’s also an important part of the mix of non-fossil-fuel electricity options we’re going to need going forward. And getting it out of the ground and turned into useful materials, including its radioactive offspring plutonium, is anything but easy.

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How To Properly Patch Your Iowa-Class Battleship

April 6, 2024 by 28 Comments

There’s a saying among recreational mariners that the word “boat” is actually an acronym for “bring out another thousand”, as it seems you can’t operate one for long without committing to expensive maintenance and repairs. But this axiom isn’t limited to just civilian pleasure craft, it also holds true for large and complex vessels — although the bill generally has a few more zeros at the end.

Consider the USS New Jersey (BB-62), an Iowa-class battleship that first served in the Second World War and is now operated as a museum ship. Its recent dry docking for routine repair work has been extensively documented on YouTube by curator [Ryan Szimanski], and in the latest video, he covers one of the most important tasks crews have to attend to while the ship is out of the water: inspecting and repairing the hundreds of patches that line the hull.

These patches aren’t to repair damage, but instead cover up the various water inlets and outlets required by onboard systems. When New Jersey was finally decommissioned in 1991, it was hauled out of the water and plates were welded over all of these access points to prevent any potential leaks. But as the Navy wanted to preserve the ship so it could potentially be reactivated if necessary, care was taken to make the process reversible.

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Fictional Computers: The Three Body Problem

April 5, 2024 by 54 Comments

If you intend to see the Netflix series “The Three Body Problem” or you want to read the Hugo-winning story from Chinese author [Cixin Liu], then you should probably bookmark this post and stop reading immediately. There will be some mild spoilers. You have been warned.

While the show does have some moments that will make your science brain cringe, there is one scene that shows a computer that could actually be built. Would it be practical? Probably not in real life, but in the context provided by the show, it was perfectly feasible. It could have, however, been done a little better, but the idea was — like many great ideas — both deceptively simple and amazingly profound. The computer was made of human beings. I’m not talking like Dune’s mentats — humans with super brains augmented by drugs or technology. This is something very different.

Background

This is your last chance. There are spoilers ahead, although I’ll try to leave out as much as I can. In the story, top scientists receive a mysterious headset that allows them to experience totally immersive holodeck-style virtual reality. When they put the headset on, they are in what appears to be a game. The game puts you in a historical location — the court of Henry VIII or Ghengis Kahn. However, this Earth has three suns. The planet is sometimes in a nicely habitable zone and sometimes is not. The periods when the planet is uninhabitable might have everything bursting into flames or freezing, or there might not be sufficient gravity to hold them on the planet’s surface. (Although I’ll admit, I found that one hard to grasp.)

Apparently, the inhabitants of this quasi-Earth can hibernate through the “chaotic eras” and wait for the next “stable era” that lasts a long time. The problem, as you probably know, is that there is no general closed-form solution for the three-body problem. Of course, there are approximations and special cases, but it isn’t easy to make long-term predictions about the state of three bodies, even with modern computers.

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Mining And Refining: Tungsten

April 2, 2024 by 16 Comments

Our metallurgical history is a little bit like a game of Rock, Paper, Scissors, only without the paper; we’re always looking for something hard enough to cut whatever the current hardest metal is. We started with copper, the first metal to be mined and refined. But then we needed something to cut copper, so we ended up with alloys like bronze, which demanded harder metals like iron, and eventually this arms race of cutting led us to steel, the king of metals.

But even a king needs someone to keep him in check, and while steel can be used to make tools hard enough to cut itself, there’s something even better for the job: tungsten, or more specifically tungsten carbide. We produced almost 120,000 tonnes of tungsten in 2022, much of which was directed to the manufacture of tungsten carbide tooling. Tungsten has the highest melting point known, 3,422 °C, and is an extremely dense, hard, and tough metal. Its properties make it an indispensible industrial metal, and it’s next up in our “Mining and Refining” series.

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