Author: Al Williams

4508 Articles

A Steam Engine For Empty Beer Cans

October 27, 2022 by 10 Comments

If Hero — the ancient Greek inventor — had been able to enjoy a beer after work, he might have pulled a trick like [BevCanTech] did: use it to create a simple steam engine. Of course, we aren’t sure why it has to be a beer can, but even with a soda can there is a fundamental problem: the can is open, assuming you’ve already enjoyed the beverage.

A pressure vessel with a big gaping hole in it isn’t much of a pressure vessel. The resealing process was actually quite simple. First, you bend back the tab to close up the opening as best you can. Next, you use cyanoacrylate glue and baking soda to seal up what’s left. We wondered if you could use epoxy, hot glue, or UV-curable resin. The top might get too hot for hot glue to last, but we aren’t sure.

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Computing Fluidly

October 27, 2022 by 20 Comments

Computers come in many forms, depending on your definition. We’ve seen computers and computer gates built out of things as diverse as marbles, relays, and — of course — transistors. However, there are logic gate systems that use a property of moving fluids to form logic gates and a bistable element. That’s all the pieces you need to build a working computer.

It may sound far-fetched, but there have been general-purpose computers built using this technology. It is also used in specialized applications where fluids are already flowing, like shower heads, automotive transmissions, and in places where electronics are prone to misbehave. Many think the field will see a resurgence when we need to build logic at the molecular level for nanotech applications, too.

Basics

In its most basic form, a fluidic gate uses flow as a logic 1 and less flow to be a logic 0. Merging two streams together provides an OR gate. Using a supply stream that you can divert with a control stream provides a NOT function. Given enough inverters and OR gates, you can build everything else.

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Cat9 And LASH Want To Change Your Linux Command Line

October 26, 2022 by 44 Comments

It is no secret that to be a true Linux power user you have to deal with the command line. Many people actually prefer to use the command line. However, the shell — the program that provides that command line — is mired in a back history which means it has to work with existing things no matter how modern it tries to be. However, a new set of projects wants to replace most of your user interface stack starting with the shell. At the top of that stack is Cat9 which is technically a shell, but not in the way you probably imagine a shell.

A traditional shell lets you run programs one at a time, feed them input, and observe their output. Sure, you can stash the output away for later use. You can run programs in the background or in parallel, but that requires special attention. In Cat9, everything is asynchronous and results stay around until you deliberately drop them. It is trivial to grab data from a previous command or, for example, to switch to a directory that was in use by an earlier task.

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3D Printing Gets Small In A Big Way

October 26, 2022 by 8 Comments

If you have a 3D printer in your workshop, you probably fret more about how to get bigger objects out of it. However, the University of Amsterdam has a new technique that allows for fast large-scale printing with sub-micron resolution. The technique is a hybrid of photolithography and stereolithography.

One of the problems with printing with fine detail is that print times become very long. However, the new technique claims to have “acceptable production time.” Apparently, bioprinting applications are very much of interest to the technology’s first licensee. There is talk of printing, for example, a kidney scaffold in several hours or a full-sized heart scaffold in less than a day.

Another example application is the production of a chromatography instrument with 200 micron channels and 20 micron restrictions. This requires a printer capable of very fine detail. There are also applications in semiconductors and mechanical metamaterials. Of course, we always take note of photolithography processes because we use them to make PC boards and even integrated circuits. A desktop printer that could do photolithography might open up new ideas for producing electronic circuitry.

If you want to play with photolithography today, [Ben Krasnow] has some advice. Of course, there are several ways to produce PC boards, even with a garden-variety 3D printer.

The $300,000 3D Printed Car

October 25, 2022 by 25 Comments

We’ve noticed an uptick in cars–especially pricey ones–using 3D-printed parts. However, these are usually small and nonstructural parts with a few exceptions. This isn’t the case with the 2024 Cadillac Celestiq. The $300,000 luxury electric vehicle boasts 115 3D-printed parts, according to a post on [TheDrive].

It appears part of the drive–no pun intended–is to allow ultra customizations for people who need more than a car that costs more than a quarter of a million dollars. For example, if you buy an Escalade — another Cadilac vehicle — you have to tolerate that the switches that operate the window are the same as Joe Sixpack has in his Tahoe. Not so, the Celestiq since it has 3D printed switches that could even be customized for a specific owner. The post mentions that the large steering wheel trim is all printed so having, for example, your name, family crest, or company logo embedded in it would be feasible.

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Less Is More When It Comes To Sensor Power

October 25, 2022 by 26 Comments

It used to be the cost of a microcontroller was a big inhibitor to putting brains in everything, but those days are long gone. Even 32-bit CPUs are now cheap enough that you can throw them into anything. The biggest factor now is probably power. Do you really want to charge your electric toilet seat or change batteries every few weeks? A company called Everactive wants you to ditch your battery using their sensor platform they claim harvests energy from a variety of sources and they are about to deliver their first developer’s kit.

The sensor can measure temperature, humidity, pressure, magnetic field, and acceleration on three axes. The device claims to harvest energy from radio frequencies, vibrations, small temperature differentials or light, even indoors. Our guess is that the sensor package runs on very little and when you poll the device wirelessly, the incoming radio signal supplies power for communication. The company claims its device uses 1000 times less power than competing solutions.

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Build Your Own Concrete 3D Printer

October 25, 2022 by 20 Comments

We didn’t notice [Nikita]’s post about building a concrete 3D printer, a few months ago, but the idea seems sound: build a basic CNC XY axis and then add a mortar pump and hose to deposit concrete. The video, below, shows the machine in operation.

While it looks interesting, there is essentially no real Z-axis, so this would be limited to some sort of relatively thin forms unless you, perhaps, did a few layers and then further lifted the machine. We also assume wet concrete won’t bridge at all. Still, this might be an interesting project, especially if you have a spare CNC XY axis floating around.

If you buy everything, though, you are looking at an estimated cost of around $7,000 USD. We presume there is enough weight in the concrete that a conventional 3D printer probably isn’t going to cut it. We did wonder, though, if there would be any merit to connecting a conventional plastic-extruding nozzle to be able to lay down support for the concrete.

This might be a good jumping-off point for a more sophisticated machine. In particular, [Nikita] points out that a progressive cavity pump with a variable frequency drive is ideal, because it allows you to vary the extrusion rate and provides a steady flow of concrete. Armed with that knowledge, you could probably figure out the rest pretty easily if you’ve ever built a 3D printer or CNC machine.

Not the first concrete printer we’ve seen, of course. The one we saw before was capable of some pretty amazing things.

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