Linux Fu: Build A Better Ls

Ask someone to name all the things they can find in a room. Only a few will mention air. Ask a Linux command line user about programs they use and they may well forget to mention ls. Like air, it is seemingly invisible since it is so everpresent. But is it the best it can be? Sure, you can use environment variables and aliases to make it work a little nicer, but, in fact, it is much the same ls we have used for decades. But there have always been moves to make better ls programs. One of them, exa, was recently deprecated in favor of one of its forks, eza.

One thing we liked about eza is that it is a single file. No strange installation. No multiple files to coordinate. Put it on your path, and you are done. So installation is easy, but why should you install it?

Continue reading “Linux Fu: Build A Better Ls”

Homebrew Linear Actuators Improved

[Harrison Low] published some 3D-printed linear actuators, which generated a lot of interest. He got a lot of advice from people on the Internet, and he took it to heart. The result: an improved version that you can see in the video below.

The original design used carbon fiber and Kevlar and was quite stiff. The actuators could move very fast, which was important to [Harrison]. However, they were also prone to wear and had issues with the force required to assemble them. He also wanted the design to be more modular to facilitate repair. The new design removes the bowden tubes, and the resulting actuator is both easier to assemble and easier to service.

Continue reading “Homebrew Linear Actuators Improved”

Will RadioShack Return?

We suspect that if you want to write a blockbuster movie or novel, the wrong approach is to go to a studio or publisher and say, “I have this totally new idea that is like nothing you’ve ever seen before…” Even Star Trek was pitched to the network as “Wagon Train to the stars.” People with big money tend to want to bet on things that have succeeded before, which is why so many movies are either remakes or Star Trek XXII: The Search for 4 PM Dinner Specials. Maybe that’s what the El Salvador-based Unicomer Group had in mind when they bought one of our favorite brands, RadioShack. They are reportedly planning a major comeback for the beleaguered brand both online and in the physical world.

In all fairness, the Shack may be better in our memories than in our realities. It was handy to stop off and pick up a coax connector, even if it cost three times the going rate for one. There was a time when RadioShack offered reasonable parts for projects, and it seems like near the end, they tried to hit that target again, but for many years, you could not find the typical parts for a modern project there anyway. However, Unicomer isn’t just a random group of investors.

Continue reading “Will RadioShack Return?”

Hackaday Podcast 235: Licorice For Lasers, Manual Motors, And Reading Resistors

Name one other podcast where you can hear about heavy 3D-printed drones, DIY semiconductors, and using licorice to block laser beams. Throw in homebrew relays, a better mouse trap, and logic analyzers, and you’ll certainly be talking about Elliot Williams and Al Williams on Hackaday Podcast 235.

There’s also contest news, thermoforming, and something that looks a little like 3D-printed Velcro. Elliot and Al also have their semi-annual argument about Vi vs. Emacs. Spoiler alert: they decided they both suck.

Missed any of their picks? Check out the links below, and as always, tell us what you think about this episode in the comments!

Download it yourself. You can even play it backwards if you like.

Continue reading “Hackaday Podcast 235: Licorice For Lasers, Manual Motors, And Reading Resistors”

Fitting 3D Prints In A Snap

The good news is that 3D printing lets you iterate on your design until it is just right. The bad news is that you often have to iterate your design over and over to get things to fit together. It is a little easier if you are designing both parts, but matching sizes and positions on a printed part that fits something that already exists can be a pain. Sure, you can grab the calipers and make fidgety measurements — but [Maker Tales] has a different approach. As you can see in the video below, he takes a photo, imports it into CAD, scales it, and then uses it as a reference.

If you have one, you could, of course, scan the existing part. However, if you’ve ever tried that, results vary wildly, especially with cheap hardware. [Maker Tales] just takes a picture with his phone, trying to get as straight as possible and from a distance. Once in CAD, he makes one measurement and scales the image to the correct size.

This is one of those things that should be obvious, but you don’t always think it through. Of course, it is possible to measure everything precisely or — even better — if you have the original CAD or drawing for the part that has exact measurements. But compared to making numerous precise measurements, this method is a lot less work and gives good results.

If you are creating mating parts, think about shadow lines. Many commercial parts now have CAD models as STEP files if you want to skip the scanning.

Continue reading “Fitting 3D Prints In A Snap”

[Thomas Sanladerer]’s YouTube Channel Goes In The Toilet

We like [Thomas Sanladerer], so when we say his channel has gone in the toilet, we mean that quite literally. He had a broken toilet and wanted to compare options for effecting a 3D printed repair. The mechanism is a wall-mounted flush mechanism with a small broken plastic part. Luckily, he had another identical unit that provided a part that wasn’t broken.

The first attempt was to 3D scan the good part. The first scanner’s software turned out to be finicky, and [Thomas] finally gave up on it. He finally used a handheld scanner which took about a half hour. It wasn’t, of course, perfect, so he also had to do some more post-processing.

The next step was to make measurements and draw the part in CAD. It took the same amount as the scan, and it is worth noting that the part had curves and angles — it wasn’t just a faceplate. The printed results were good, although a measurement error made the CAD model bind a bit instead of pivoting the way it should. The scan, of course, got it right.

A quick revision of the design solved that problem but, of course, it added some time to the process. At the end, he noticed that the scanned “good” part was also broken but in a different way. He added the additional part, which didn’t seem to bother the function. The scanned object required a little trimming but nothing tremendous.

In the end, the scanning was a bit quicker, partly because it didn’t suffer from the measurement error. However, [Thomas] noted that it was more fun to work in CAD. We thought the results looked better, anyway. [Thomas] thinks the scanners, at least the budget ones, are probably better for just getting reference objects into CAD to guide you when you create the actual objects to print.

It isn’t hard to make a cheap scanner. Some of the open designs are quite sophisticated.

Continue reading “[Thomas Sanladerer]’s YouTube Channel Goes In The Toilet”

Triso Fuel And The Rolls Royce Of Nuclear Reactors

Bangor University scientists think that the way to go big with nuclear power is to, in fact, go small. Their tiny nuclear fuel pellets called triso fuel are said to be the size of poppy seeds and are meant to power a reactor by Rolls Royce the size of a “small car.” We aren’t sure if that’s a small Rolls Royce or a small normal car.

The Welsh university thinks the reactor has applications for lunar bases, here on Earth, and even on rockets because the reactor is so small. We can’t tell if the fuel from Bangor is unique or if it is just the application and the matching reactor that is making the news. Triso fuel — short for tri-structural isotropic particle fuel — was developed in the 1960s, and there are multiple projects worldwide gearing up to use this sort of fuel.

Continue reading “Triso Fuel And The Rolls Royce Of Nuclear Reactors”