Engineering

578 Articles

Feeling The Heat: Railway Defect Detection

March 28, 2023 by 29 Comments

On the technology spectrum, railroads would certainly seem to skew toward the brutally simplistic side of things. A couple of strips of steel, some wooden ties and gravel ballast to keep everything in place, some rolling stock with flanged wheels on fixed axles, and you’ve got the basics that have been moving freight and passengers since at least the 18th century.

But that basic simplicity belies the true complexity of a railway, where even just keeping the trains on the track can be a daunting task. The forces that a fully loaded train can exert on not only the tracks but on itself are hard to get your head around, and the potential for disaster is often only a failed component away. This became painfully evident with the recent Norfolk Southern derailment in East Palestine, Ohio, which resulted in a hazardous materials incident the likes of which no community is ready to deal with.

Given the forces involved, keeping trains on the straight and narrow is no mean feat, and railway designers have come up with a web of sensors and systems to help them with the task of keeping an eye on what’s going on with the rolling stock of a train. Let’s take a look at some of the interesting engineering behind these wayside defect detectors.

Continue reading “Feeling The Heat: Railway Defect Detection” →

A freshly reballed BGA chip next to a clean PCB footprint

Working With BGAs: Soldering, Reballing, And Rework

March 23, 2023 by 31 Comments

In our previous article on Ball Grid Arrays (BGAs), we explored how to design circuit boards and how to route the signals coming out of a BGA package. But designing a board is one thing – soldering those chips onto the board is quite another. If you’ve got some experience with SMD soldering, you’ll find that any SOIC, TQFP or even QFN package can be soldered with a fine-tipped iron and a bit of practice. Not so for BGAs: we’ll need to bring out some specialized tools to solder them correctly. Today, we’ll explore how to get those chips on our board, and how to take them off again, without spending a fortune on equipment.

Tools of the Trade

For large-scale production, whether for BGA-based designs or any other kind of SMD work, reflow ovens are the tool of choice. While you can buy reflow ovens small enough to place in your workshop (or even build them yourself), they will always take up quite a bit of space. Reflow ovens are great for small-scale series production, but not so much for repairs or rework. Continue reading “Working With BGAs: Soldering, Reballing, And Rework” →

PCIe For Hackers: The Diffpair Prelude

March 14, 2023 by 35 Comments

PCIe, also known as PCI-Express, is a highly powerful interface. So let’s see what it takes to hack on something that powerful. PCIe is be a bit intimidating at first, however it is reasonably simple to start building PCIe stuff, and the interface is quite resilient for hobbyist-level technology. There will come a time when we want to use a PCIe chip in our designs, or perhaps, make use of the PCIe connection available on a certain Compute Module, and it’s good to make sure that we’re ready for that.

PCIe is everywhere now. Every modern computer has a bunch of PCIe devices performing crucial functions, and even iPhones use PCIe internally to connect the CPU with the flash and WiFi chips. You can get all kinds of PCIe devices: Ethernet controllers, high-throughput WiFi cards, graphics, and all the cheap NVMe drives that gladly provide you with heaps of storage when connected over PCIe. If you’re hacking on a laptop or a single-board computer and you’d like to add a PCIe device, you can get some PCIe from one of the PCIe-carrying sockets, or just tap into an existing PCIe link if there’s no socket to connect to. It’s been two decades since we’ve started getting PCIe devices – now, PCIe is on its 5.0 revision, and it’s clear that it’s here to stay.

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A Hacker’s Introduction To DIY Light Guide Plates

March 13, 2023 by 38 Comments

Last year, I found myself compelled to make a scaled-down replica of the iconic test chamber signs from the video game Portal. If you’ve played the game, you’ll remember these signs as the illuminated monoliths that postmarked the start of every test chamber. In hyperstylized video game fashion, they were also extremely thin.

Stay tuned for cake at the end of this article.

True to the original, my replica would need to be both slimmed down and backlit with a uniform, natural white glow. As fate would have it, the crux of this project was finding a way to do just that: to diffuse light coming in from the edges so that it would emit evenly from the front.

What I thought would be quick project ended up being a dive down the rabbit hole that yielded some satisfying results. Today, I’d like to share my findings and introduce you to light guide plates, one of the key building blocks inside of much of today’s backlit screen technology. I’ll dig into the some of the working principles, introduce you to my homebrew approach, and leave you with some inspirational source code to go forth and build your own. Continue reading “A Hacker’s Introduction To DIY Light Guide Plates” →

Daniel Valuch Chats About CERN’s High Caliber Hacking

March 3, 2023 by 9 Comments

For those of us who like to crawl over complex systems, spending hours or even days getting hardware and software to work in concert, working at places like NASA or CERN seems like a dream job. Imagine having the opportunity to turn a wrench on the Space Shuttle or the Large Hadron Collider (LHC) — not only do you get to spend some quality time with some of the most advanced machines ever produced, you can be secure in the knowledge that your work will further humanity’s scientific understanding of the universe around us.

Or at least, that’s what we assume it must feel like as outsiders. But what about somebody who’s actually lived it? What does an actual employee, somebody who’s had to wake up in the middle of the night because some obscure system has gone haywire and stalled a machine that cost taxpayers $4.75 billion to build, think about working at the European Organization for Nuclear Research? Continue reading “Daniel Valuch Chats About CERN’s High Caliber Hacking” →

How Hard Could It Be To Get Millions Of Phone Bills Right?

March 2, 2023 by 46 Comments

It may be a foreign concept to anyone who has never paid a dime for a phone call over and above the monthly service charge, but phone calls were once very, VERY expensive — especially long-distance calls, which the phone company ungenerously defined as anything more than a few towns away. Woe betide the 70s teen trying to talk to out-of-town friends or carry on a romance with anyone but the guy or girl next door when that monthly phone bill came around; did anyone else try to intercept it from the mailbox before the parents could see it?

While it seems somewhat quaint now, being charged for phone calls was not only a big deal to the customers, but to the phone company itself. The Bell System, which would quickly become a multi-billion dollar enterprise, was built on the ability to accurately meter the use of their service and charge customers accordingly. Like any engineered system, it grew and changed over time, and it had to adapt to the technologies and economic forces at the time.

One of the most interesting phases of its development was the development of Automatic Message Accounting (AMA), which in a very real way paved the way for the wide-open, worldwide, too-cheap-to-meter phone service we enjoy today.

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Move Over Steel, Carbon-Reinforced Concrete Is Here

February 28, 2023 by 62 Comments

Reinforced concrete is the miracle material which made possible so many of the twentieth century’s most iconic structures, but here in this century its environmental footprint makes it something of a concern. As part of addressing this problem, a team at TU Dresden in Germany have completed what is believed to be the world’s first building made with carbon-reinforced concrete, in which the steel rebar is replaced with carbon fiber.

New materials are always of interest here at Hackaday, so it’s worth reading further about the nature of the reinforcement. The carbon fiber is woven into a mesh, or as a composite material that mimics existing rebar structures. These two types of reinforcement can be combined in a composite to produce a concrete structure much lighter than traditional steel-reinforced ones. If you page through the architecture critic description, it’s this lightness which has enabled the curving structure of the Dresden building to be so relatively thin.

The carbon saving comes presumably in the lower energy cost from not smelting iron to make steel, as well as the need for less concrete due to the lightness. All we need now is a low-carbon replacement for Portland cement.

Want to know more about concrete reinforcement? We’ve got you covered.