Most 3D printers use leadscrews for at least one axis. These are simple devices that are essentially a steel screw thread and a brass nut that travels on it. However, for maximum precision, you’d like to use a ball screw. These are usually very expensive but have many advantages over a leadscrew. [MirageC] found cheaper ball screws but, since they were inexpensive, they had certain limitations. He designed a simple device that improves the performance of these cheap ball screws.
Superficially, a ball screw looks like a leadscrew with an odd-looking thread. However, the nut is very different. Inside the nut are ball bearings that fit in the grooves and allows the nut to spin around with much less friction. A special path collects the ball bearings and recirculates them to the other side of the nut. In general, ball screws are very durable, can handle higher loads and higher speeds, and require less maintenance. Unlike leadscrews, they are more expensive and are usually quite rigid. They are also a bit noisier, though.
Ball screws are rated C0 to C10 precision where C10 is the least accurate and the price goes up — way up — with accuracy. [MirageC] shows how cheaper ball screws can be rolled instead of precision ground. These screws are cheaper and harder, but exhibit more runout than a precision screw.
This runout caused wobble during 3D printing that was immediately obvious on the prints. Using a machinist’s dial gauge, [MirageC] found the screws were not straight at all and that even a relatively poor C7 ball screw would be more precise.
The solution? A clever arrangement of 3D printed parts. ball bearings, and magnets. The device allows the nut to move laterally without transmitting it to the print bed. It is a clever design and seems to work well.
It was around the year 1590 when mankind figured out how to use optical lenses to bring into sight things smaller than the natural eye can observe. With the invention of the microscope, a new and unexplored world was discovered. It will likely be of great surprise to the reader that scientists of the time did not believe that within this new microscopic realm lay the source of sickness and disease. Most would still hold on to a belief of what was known as Miasma theory, which dates back to the Roman Empire. This theory states that the source of disease was contaminated air through decomposing organic materials. It wouldn’t be until the 1850’s that a man by the name of Louis Pasteur, from whom we get “pasteurization”, would promote Germ Theory into the spotlight of the sciences.
Pasteur, considered by many as the father of microbiology, would go on to assist fellow biologist Charles Chameberland in the invention of the aptly named Pasteur Chamberland filter — a porcelain filter with a pore size between 100 and 1000 nanometers. This was small enough to filter out the microscopic bacteria and cells known at that time from a liquid suspension, leaving behind a supply of uncontaminated water. But like so many other early scientific instrumentation inventions it would lead to the discovery of something unexpected. In this case, a world far smaller than 100 nanometers… and add yet another dimension to the ever-shrinking world of the microscopic.
A bench oscilloscope is one of the most invaluable tools in the hardware hacker’s arsenal, but even the slimmest digital models are a bit large to be part of your everyday electronic carry. Sure you could throw one of those cheap pocket scopes in your bag, but what if there was an even easier way to take a peek at a few signals while you’re on the go?
For those who roam, the Arduino-web-oscilloscope project created by [David Buezas] is worth a close look. Using the Web Serial API built into recent versions of Google’s Chrome browser, this project allows you to pop open a software oscilloscope without installing anything locally. Whether it’s a public computer or that cheap Chromebook you keep around for emergencies, a valuable tool is just a few clicks away.
Flashing the MCU from the web interface.
Of course, there has to be some hardware involved. Despite what you might think given the name of the project, the code currently only supports the Logic Green LGT8F328P microcontroller. This cheap ATmega328P clone not only runs at 32 Mhz but according to [David], many operations can be done in fewer clock cycles than on the original 328P. In short it’s fast, and fast is good if you want more samples.
One of the best parts about this project is that a function to flash the firmware to the LGT8F328P is built right in the web interface. With the oscilloscope running in the browser, you just need to plug in a blank board, click the button to flash it, and start taking measurements. You could outfit a whole classroom or hackerspace with basic oscilloscopes in minutes, with a per-seat cost of just a few bucks.
Now as you might expect, there are some pretty hard limits on what you can realistically measure with this setup. For one thing, the board can’t handle anything higher than 5 volts. Even the cheapest oscilloscope kit is still going to be an upgrade, but the fact you can spin this up almost anywhere for the cost of a cheap MCU board makes it hard to complain about the results.
There’s a satisfaction in watching someone else at work, particularly when they are demonstrating a solution to a soldering problem you have encountered in the past. SMA panel sockets have a particularly tiny solder bucket on their reverse, and since they often need to be soldered onto brass rod as part of microwave antenna construction they present a soldering challenge. [Andrew McNeil] is here to help, with a foolproof method of achieving a joint that is both electrically and mechanically sound.
The best connections to a solder bucket come when the wire connected to it nestles within its circular center. If this doesn’t happen and a blob of solder merely encapsulates both wire and bucket, the mechanical strength of the solder blob alone is not usually sufficient. The brass rod is wider than the bucket, so he takes us through carefully grinding it down to the right diameter for the bucket so it sits in place and can have the solder sweated into the gap. The result is very quick and simple, but has that essential satisfaction we mentioned earlier. It’s a small hack, but if you’ve ever soldered to a too-small RF connector you’ll understand. For more fun and games with RF connectors, take a look at our overview.
With innumerable microcontroller boards on the market it’s sure that there will be one for every conceivable application or user. Among them are some seriously tiny ones, but this wasn’t enough for [Alun Morris]. Wanting to see how small he could make an ATtiny board without a custom PCB, he took a SOIC-8 version of the popular minimalist processor and mated it to a 6mm by 8mm piece of 0.05″ prototyping board to create a device that is dwarfed by its connectors.
It’s an extremely simple circuit and hardly something that hasn’t been done before, but the value here is in the tricky soldering to make it rather than its novelty. The ATtiny402 and three passive SMD components are fitted on the smallest possible sliver of prototyping board to contain them, and the female headers and set of programming pins contribute far more to the volume of the device than the board itself. He also tried a side-on design with two smaller slivers of board before settling on the more conventional layout. The demonstration of the system in action seen in the video below the break is a magnetic flux detector, dwarfed by the 40-pin DIP Z80 it is sitting on.
A lot of boards claim to be tiny, but few are this small. This ESP32 is a more usual contender.
Is there any garment so freeing to wear as a skirt, assuming it isn’t skin tight? (Well, unless that’s your thing — we won’t judge.) Skirts and dresses are pretty darn freeing compared to pants, so it’s too bad that most of them come without pockets. And it’s really too bad that pretty much all skirts and dresses come without RGB LEDs that can react to movement. Maybe someday.
Until then, we’ll just have to design our own LED skirt like [makeTVee] and his girlfriend did, and hope that it looks half as good. This skirt has six RGB LED strips running down the front for a total of 120 LEDs. The strips are held in place with hook and loop tape and all the electronics — an Adafruit QT Py, a 6-DOF IMU, and a USB power bank — are tucked into the waistband and can be easily removed when it’s time to wash the skirt. Continuing with the practicality theme, there are no LEDs on the back, though they could easily be added in for getting down on the dance floor.
We really love the fabric choices here. The overlay fabric looks good on its own, but it also does a great job of showing and diffusing the light, while at the same time hiding the LED strips themselves. It’s clear that they took comfort and practicality into consideration and made a wearable that’s truly wearable. [makeTVee] calls this a work in progress, but has already got a few nice animations going, which you can see in the video after the break.
Well, that was quite a show! The Perseverance rover arrived on Mars Thursday. Don’t tell the boss, but we spent the afternoon watching the coverage in the house on the big TV rather than slaving away in the office. It was worth it; for someone who grew up watching Jules Bergman and Frank Reynolds cover the Apollo program and the sometimes cheesy animations provided by NASA, the current coverage is pretty intense. A replay of the coverage is available – skip to about the 1:15:00 mark to avoid all the filler and fluff preceding the “Seven Minutes of Terror” main event. And not only did they safely deliver the package, but they absolutely nailed the landing. Perseverance is only about 2 km away from the ancient river delta it was sent to explore for signs of life. Nice shooting!
We’re also being treated to early images from Jezero crater. The first lowish-rez shots, from the fore and after hazard cameras, popped up just a few seconds after landing — the dust hadn’t even settled yet! Some wags complained about the image quality, apparently without thinking that the really good camera gear was stowed away and a couple of quick check images with engineering cameras would be a good idea while the rover still had contact with the Mars Reconnaissance Orbiter. Speaking of which, the HiRISE camera on the MRO managed to catch a stunning view of Perseverance’s descent under its parachute; the taking of that photo is an engineering feat all by itself. But all of this pales in comparison to a shot from one of the down-looking cameras in the descent stage, show Perseverance dangling from the skycrane just before touchdown. It was a really good day for engineering.
Would that our Earthly supply chains were as well-engineered as our Martian delivery systems. We’ve been hearing of issues all along the electronics supply chain, impacting a wide range of industries. Some of the problems are related to COVID-19, which has sickened workers staffing production and shipping lines. Some, though, like a fire at the AKM semiconductor plant in Japan, have introduced another pinch point in an already strained system. The fire was in October, but the impact on the manufacturer depending on the plant’s large-scale integration (LSI) and temperature-compensated crystal oscillators (TCXO) products is only just now being felt in the amateur radio market. The impact is likely not limited to that market, though — TCXOs pop up lots of gear, and the AKM plant made LSI chips for all kinds of applications.
What do you get when you combine a 3D-printer, a laser cutter, a CNC router, and a pick-and-place robot? Drones that fly right off the build plate, apparently. Aptly enough, it’s called LaserFactory, and it comes from MITs Computer Science and Artificial Intelligence Lab. By making different “bolt-on” tools for a laser cutter, the CSAIL team has combined multiple next-generation manufacturing methods in one platform. The video below shows a drone frame being laser-cut from acrylic, to which conductive silver paste is added by an extruder. A pick-and-place head puts components on the silver goo, solders everything together with a laser, and away it goes. They also show off ways of building up 3D structures, both by stacking up flat pieces of acrylic and by cutting and bending acrylic in situ. It’s obviously still just a proof of concept, but we really like the ideas presented here.
And finally, as proof that astronomers can both admit when they’re wrong and have fun while doing so, the most remote object in the Solar System has finally received a name. The object, a 400-km diameter object in a highly elliptical orbit that takes it from inside the orbit of Neptune to as far as 175 astronomical units (AU) from the Sun, is officially known as 2018 AG37. Having whimsically dubbed the previous furthest-known object “Farout,” astronomers kept with the theme and named its wayward sister “Farfarout.” Given the rapid gains in technology, chances are good that Farfarout won’t stay the Sun’s remotest outpost for long, and we fear the (Far)nout trend will eventually collapse under its own weight. We therefore modestly propose a more sensible naming scheme, perhaps something along the lines of “Farthest McFaraway.” It may not scale well, but at least it’s stupid.
