Fridge Compressor Teardown Reveals Engineering Compromises

August 20, 2022 by 108 Comments

Probably one of the most reliable devices you will have in your house is the refrigerator, as its compressor has the minimum of moving parts and carries its own lubrication. It’s not uncommon to find fridges many decades old still in use, and fridges are far more likely to be discarded due to broken fittings rather than a failed compressor. An interesting teardown of a failed fridge compressor comes from [turbokinetic], who gives us a professional analysis of how shortcomings in its construction caused it to fail. It’s both an opportunity for a look at the inside of a fridge compressor, and a commentary on the quality of consumer grade hardware.

Electrically the unit seemed unhurt, but the motor wouldn’t pump anything. Cutting the lid off revealed the motor, and it was soon established that the bearing had failed. As the teardown proceeded the conclusion was that the fault lay in the oil being too low viscosity. The designer had picked a very light oil in pursuit of low friction for lower energy consumption, but had ended up with one too light to provide adequate coverage within the bearing. The compressor has a lifetime of around ten years baked into it from manufacture, whether the designer intended it to or not.

You can see the full video below the break, but meanwhile this isn’t the first fridge compressor we’ve seen.

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Keycap Shine? No, Shiny Keycaps

August 19, 2022 by 34 Comments

No matter how often you wash your hands, ABS keycaps will eventually exhibit shine wherever you strike them the most. And that’s the problem right there: the shine might be okay if it were somehow uniform across the surface of the keycaps, but instead it just tends to make one feel seen. And since there’s really nothing you can do except to replace your keycaps (or start with PBT), you might as well embrace the shine, right?

Well, that’s how [mmalluck] feels, anyway. He recently experimented with using acetone vapors to refinish a set of keycaps from Drop, making them super-duper shiny in the process. Now, the operative word here is vapors, because straight acetone would acid-wash those ‘caps faster than you can say ‘bad idea jeans’.

So to that end, [mmalluck] poured acetone in a glass cake pan, used a piece of cardboard to separate the keycaps from the acetone, and covered it all with a glass cutting board. It doesn’t take very long to achieve a good result, and [mmalluck] says it’s better to err on the side of too-short instead of risking reaching the point of too-melted.

We wouldn’t have thought we’d react this way, but we think they’re pretty cool looking. That particular set seems just right for this process, which makes them look like new old-stock typewriter keys or something. Looks way better than the ultra-personalized shine of usage. What do you think? Let us know in the comments.

Via KBD #90

Rŏ̽ta: Counting, With Style

August 19, 2022 by 3 Comments

Rǒta counts things. That’s it, really — what a cheap little mechanical counter does with a thumb press, or what you can do by counting on your fingers and toes, that’s pretty much all that Rǒta does. But it does it with style.

OK, that’s being a bit unfair to [Kevin Santo Cappuccio] — Rǒta has a few more tricks up its sleeve than simple counting. But really, those functions are just icing on the cake of how this little gadget looks. Rǒta was built around the unbeatable combination of a rotary telephone dial mechanism and a trio of Nixie tubes. The dial looks like it might have come from an old pay phone, all shiny and chrome and super robust looking. The Nixies sit atop the dial on a custom PCB, and everything, including the high-voltage supply for the tubes, is enclosed in a 3D printed case with a little bit of a Fallout vibe.

But what does this thing do? Actually, quite a lot. It’ll count up and down, using whatever number you dial into it. You can either increment from zero, or enter any three-digit number as the starting count. It keeps track of the score of your golf game, if that’s your thing, and it’s also got a stopwatch function. You can even dial up a display of the current battery voltage. It takes some ingenuity to use just the dial for all these functions, but that’s as easy as dialing the operator used to be — dialing 0 puts it in menu mode, allowing you to access any of the functions printed on the card in the center of the dial. It’s pretty clever — check out the video below.

Is it particularly useful? Perhaps not. But when has that ever been a measure of the worth of a project? Something like this rotary cellphone might be more useful, but sometimes looking great is good enough.

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Hackaday Podcast 182: Sparkpunk Photography, Anti-Xiomi Air Filters, And Keyfob Foibles

August 19, 2022 by 4 Comments

Editor-in-Chief Elliot Williams and Managing Editor Tom Nardi are here to bring you the best stories and hacks from the previous week (and maybe a little older). Things kick off with news that the Early Bird tickets for the 2022 Hackaday Supercon tickets sold out in only two hours — a good sign that the community is just as excited as we are about the November event. But don’t worry, regular admission tickets are now available for those who couldn’t grab one out of the first batch.

This week there’s plenty of vehicular hacks to talk about, from John Deere tractors running DOOM to a particularly troublesome vulnerability found in many key fobs. We’ll also lament about the state of 3D CAD file formats, marvel at some retro-futuristic photography equipment, and look at the latest in home PCB production techniques. Wrapping things up there’s a whole lot of cyberdeck talk, and a trip down silicon memory lane courtesy of Al Williams.

Direct download it for yourself right here.

Check out the links below if you want to follow along, and as always, tell us what you think about this episode in the comments!

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This Week In Security: Secure Boot Bypass, Attack On Titan M, KASLR Weakness

August 19, 2022 by 9 Comments

It’s debatable just how useful Secure Boot is for end users, but now there’s yet another issue with Secure Boot, or more specifically, a trio of signed bootloaders. Researchers at Eclypsium have identified problems in the Eurosoft, CryptoPro, and New Horizon bootloaders. In the first two cases, a way-too-flexible UEFI shell allows raw memory access. A startup script doesn’t have to be signed, and can easily manipulate the boot process at will. The last issue is in the New Horizon Datasys product, which disables any signature checking for the rest of the boot process — while still reporting that secure boot is enabled. It’s unclear if this requires a config option, or is just totally broken by default.

The real issue is that if malware or an attacker can get write access to the EFI partition, one of these signed bootloaders can be added to the boot chain, along with some nasty payload, and the OS that eventually gets booted still sees Secure Boot enabled. It’s the perfect vehicle for really stealthy infections, similar to CosmicStrand, the malicious firmware we covered a few weeks ago.
Continue reading “This Week In Security: Secure Boot Bypass, Attack On Titan M, KASLR Weakness” →

Put 3D Metal Printing Services To The Test, By Making A Watch

August 18, 2022 by 17 Comments

Have you ever been tempted by those metal 3D printing services? [Carter Hurd] has, and puts them to the test with a wristwatch. (Video, embedded below.)

It’s fair to say that among Hackaday readers you will find a very high percentage of 3D printer ownership compared to the general population, but for most of us that means an FDM or perhaps even an SLA printer. These two technologies have both effectively delivered polymer printing at the affordable end of the market, but as readers will also be aware they are only the tip of the 3D printing iceberg. We know the awesomeness of your industrial 3D printer is defined by the size of your wallet, and while our wallets are small, we are offered a chance at the big time through the services of rapid prototyping companies that will print our models on these high-end machines. Thus [Carter]’s project video is as much about using these services as it is about making a wristwatch.

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Bufferbloat, The Internet, And How To Fix It

August 18, 2022 by 48 Comments

There’s a dreaded disease that’s plagued Internet Service Providers for years. OK, there’s probably several diseases, but today we’re talking about bufferbloat. What it is, how to test for it, and finally what you can do about it. Oh, and a huge shout-out to all the folks working on this problem. Many programmers and engineers, like Vint Cerf, Dave Taht, Jim Gettys, and many more have cracked this nut for our collective benefit.

When your computer sends a TCP/IP packet to another host on the Internet, that packet routes through your computer, through the network card, through a switch, through your router, through an ISP modem, through a couple ISP routers, and then finally through some very large routers on its way to the datacenter. Or maybe through that convoluted chain of devices in reverse, to arrive at another desktop. It’s amazing that the whole thing works at all, really. Each of those hops represents another place for things to go wrong. And if something really goes wrong, you know it right away. Pages suddenly won’t load. Your VoIP calls get cut off, or have drop-outs. It’s pretty easy to spot a broken connection, even if finding and fixing it isn’t so trivial.

That’s an obvious problem. What if you have a non-obvious problem? Sites load, but just a little slower than it seems like they used to. You know how to use a command line, so you try a ping test. Huh, 15.0 ms off to Google.com. Let it run for a hundred packets, and essentially no packet loss. But something’s just not right. When someone else is streaming a movie, or a machine is pushing a backup up to a remote server, it all falls apart. That’s bufferbloat, and it’s actually really easy to do a simple test to detect it. Run a speed test, and run a ping test while your connection is being saturated. If your latency under load goes through the roof, you likely have bufferbloat. There are even a few of the big speed test sites that now offer bufferbloat tests. But first, some history. Continue reading “Bufferbloat, The Internet, And How To Fix It” →