Tech In Plain Sight: Windshield Frit

January 18, 2024 by 30 Comments

You probably see a frit every day and don’t even notice it. What is it? You know the black band around your car’s windshield? That’s a frit (which, by the way, can also mean ingredients used in making glass) or, sometimes, a frit band. What’s more, it probably fades out using a series of dots like a halftone image, right? Think that’s just for aesthetics? Think again.

Older windshields were not always attached firmly, leading to them popping out in accidents. At some point, though, the industry moved to polyurethane adhesives, which are superior when applied correctly. However, they often degrade from exposure to UV. That’s a problem with a windshield, which usually gets plenty of sunlight.

The answer is the frit, a ceramic-based baked-on enamel applied to both sides of the windshield’s edges, usually using silk screening. The inner part serves as a bonding point for the adhesive. However, the outer part blocks UV radiation from reaching the adhesive. Of course, it also hides the adhesive and any edges or wiring beneath it, too.

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Deep Dive Into 3D Printing Nozzles

January 18, 2024 by 14 Comments

[Lost in Tech] set out to examine a variety of 3D printing nozzles. Before he got there, though, he found some issues. In particular, he found that his current crop of printers don’t take the standard E3D or MK8 nozzles. So, instead, he decided to examine various nozzles under the microscope.

Unsurprisingly, each nozzle had a tiny hole at the end, although the roundness of the hole varied a bit from nozzle to nozzle. As you might expect, more expensive nozzles had better orifices than the cheap ones. Grabbing pictures of nozzles at magnification isn’t easy, so he set up a special image stacking setup to get some beautiful images (and he has another video on how that works).

But the real star of the video is when he virtually travels into the orifice to show the innermost details of the nozzle from the inside out. This let him visualize the smoothness and finish. The Creality nozzles looked very good and weren’t terribly expensive. Many of the expensive nozzles were quite good. However, as you would expect, the quality of cheap nozzles were all over the place.

By the end, [Lost in Tech] speculates if the non-standard nozzles are a way to prevent you from buying low-cost nozzles and eating into sales or if they are a way to prevent you from buying low-cost nozzles that may give you poor print quality. What do you think?

There’s more than one way to look inside a nozzle. We just buy our nozzles, but some people make their own.

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Predicting The A-Bomb: The Cartmill Affair

January 18, 2024 by 18 Comments
The cover of the infamous issue of Astounding, March 1944

There’s an upcoming movie, Argylle, about an author whose spy novels are a little too accurate, and she becomes a target of a real-life spy game. We haven’t seen the movie, but it made us think of a similar espionage caper from 1944 involving science fiction author Cleve Cartmill. The whole thing played out in the pages of Astounding magazine (now Analog) and involved several other science fiction luminaries ranging from John W. Campbell to Isaac Asimov. It is a great story about how science is — well, science — and no amount of secrecy or legislation can hide it.

In 1943, Cartmill queried Campbell about the possibility of a story that would be known as “Deadline.” It wasn’t his first story, nor would it be his last. But it nearly put him in a Federal prison. Why?  The story dealt with an atomic bomb.

Nothing New

By itself, that’s probably not a big deal. H.G. Wells wrote “The World Set Free” in 1914, where he predicted nuclear weapons. But in 1914, it wasn’t clear how that would work exactly. Wells mentioned “uranium and thorium” and wrote a reasonable account of the destructive power: Continue reading “Predicting The A-Bomb: The Cartmill Affair” →

A Dim Bulb Tester Is For Testing Other Equipment, Not Bulbs

January 18, 2024 by 26 Comments

If you’re testing old stereo equipment, a dim bulb tester can really come in handy. It’s not for testing bulbs, though, it’s a tester that uses a dim bulb to test other things. [Nicholas Morganti] explains it all in his guide to making your own example of such a tool. Just be wary — you need to know what you’re doing with mains voltages to do this safely!

The dim bulb is a deceptively simple tool that nonetheless often proves useful in diagnostics. It normally just consists of a bulb connected in series with the equipment under test. The bulb is intended to be a similar wattage to the power draw of the equipment itself. Take for example, an amplifier. If the bulb glows brightly when the amp is under no load, it suggests there may be a short circuit somewhere. That’s because the glowing bulb indicates that plenty of current is being drawn under a condition when very little should be flowing. The bulb protects the equipment by essentially acting as a bit of a current limiting device. It’s a soft-start tool for a piece of vulnerable equipment.

Building one is usually as simple as gathering an enclosure, a plug receptacle, a bulb socket, and some other ancillary parts to lace everything together. [Nicholas] explains it all with clear diagrams and tells you how to follow along. It’s easy enough, but you really need to know what you’re doing to use one safely, as mains voltages are involved.

It’s a great tool to have if you’re getting into amplifier repair or similar work on old gear. If you’ve been whipping up your own must-have tools, don’t hesitate to let us know!

Android-Powered Rigol Scopes Go Wireless

January 18, 2024 by 9 Comments

The Rigol DHO800 and DHO900 series use Android underneath, and as you might expect, this makes them easier to hack. A case in point: [VoltLog] demonstrates that you can add WiFi to the scope using a cheap USB WiFi adapter. This might seem like a no-brainer on the surface, but because the software doesn’t know about WiFi, there are a few minor hoops to jump through.

The first issue is that you need a WiFi adapter the built-in OS already knows how to handle. The community has identified at least one RTL chipset that works and it happens to be in the TP-Link TL-WN725N. These are old 2.4 GHz only units, so they are widely available for $10 or less.

But even with the correct hardware, the scope doesn’t have any menus to configure the WiFi interface. To solve that, you need to temporarily use a USB hub and a USB keyboard. Once you have everything plugged in, you can use the Super + N keyboard shortcut to open up the Android notification bar, which is normally hidden. Once you’ve setup the network connection, you won’t need the keyboard anymore.

Or maybe not — it turns out the keyboard does allow you to change a few other things. For example, [VoltLog] used it to increase the screen brightness more than the default maximum setting.

The only other issue appears to be that the scope shows it is disconnected even when connected to WiFi. That doesn’t seem to impact operation, though. Of course, you could use a WiFi to Ethernet bridge or even an old router, but now you have a cable, a box, and another power cord to deal with. This solution is neat and clean. You bet we’ve already ordered a TP-Link adapter!

WiFi scopes are nothing new. We suspect Rigol didn’t want to worry about interference and regulatory acceptance, but who knows? Besides, it is fun to add WiFi to wired devices.

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Neon Watch Glows Rather Nicely, Tells Time

January 17, 2024 by 12 Comments

It wasn’t long after the development of the LED that LED watches became available. They were prized for their clear light output and low power draw. Neon bulbs, on the other hand, are thirsty for current and often warm or even hot in operation. And yet, [Lucas] found a way to build them into a sweet watch that actually does the job. Nice, right?

The design uses a simple trick to avoid killing the batteries with excessive power draw. The neon lamps are only activated when the user waves a hand above the watch, at which point the lamps light to display the time. Reading the time is  a little fiddly, but understandable with the aid of this PDF diagram. Basically, the two electrodes of each neon lamp are driven independently. This gives each of the four lamps three possible states: with the first electrode lit, the second electrode lit, or both lit. Four lamps multiplied by three states equals 12—so the watch can display the hour quite easily. As for minutes, a similar scheme is used with some modifications for clarity. Setting the time is via a light sensor on the watch which picks up flashes from a computer screen.

It reminds us of a time when we once thought nixie tubes were too power hungry for a wristwatch build… until the hackers of the world proved us wrong. Video after the break.

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Modeling Network Latency

January 17, 2024 by 6 Comments

The selfhosting community is an interesting and useful part of the Internet dedicated to removing one’s own services and data from the cloud and hosting it on their own servers, often on hardware that can be physically touched. With that kind of network usage, it’s not uncommon for people to build their own routers, firewalls, and other network support systems from the ground up. And, if you go deep enough, maybe even a home lab dedicated to testing and improving the network’s various layers. This piece of software helps simulate network latency to more accurately assess quality of service, performance, and the optimization of one one’s own networks.

The tool, called Speedbump, allows a network administer to quickly build a test network where characteristics of the network such as base latency and wave shape and size can be set up. From there, a TCP proxy sends the network traffic through the virtual network, adding in a set amount of delay to anything traveling on the network. It can be installed (or built from source) on an existing installation or used from within a Docker terminal, so there are plenty of options depending on preference. It’s also available as a library for any programs written in Go.

While this certainly has applications for home labs where self-hosting services is done at a high level, this could have professional applications as well. For troubleshooting simpler network issues we’d always recommend this tool which allows a more comprehensive network test than the standard “ping” command, and if you haven’t heard of selfhosting before it’s probably time to read this primer on it and build a hobby web server from scratch.