TechyMagThings

Exciting discoveries in particle physics are one of those things that it can be easy to get blase about. Some people get caught up in the obvious excitement, while others yawn: “Oh, you found the Higgs Boson, just like Higgs predicted. Call me when you have something new.” Well, if you’re in category B, prepare to yawn while the rest of us break out champagne, because it looks like we’ve finally found the glueball. 

The glueball has got to be one of the oddest particles to fall out of the Standard Model. It’s not a fundamental particle, but its makeup contains no quarks– those itty bits that make up protons and neutrons– nor any leptons like electrons or muons. No, the glueball is a hadron made entirely of baryons: specifically, gluons, the force-carrying particles of the strong nuclear force. It’s also been called gluonium or a gluon-ball, but glueball is more fun.

Try and imagine a proton without any quarks. Remember that inside the proton there are three quarks, held together with force-carrying gluon particles. If you have zero quarks, but enough of those gluons tangled up in the right ways, and you get a tangible, if short lived particle. That’s the glueball, a neutral particle that will decay almost immediatly in to Pions. It works because gluons have ‘colour charge’– the strong nuclear force’s answer to electric charge.

It’s also one of those things that will probably never be seen in nature: odds are, even in the hottest collisions, you’re going to get a quark or two mixed up with your gluon soup. That’s okay; the gluonic state is what we’ve been looking for. As long as the particle is mostly gluons, and behaves as the Standard Model predicts it should, physicists are inclined to call it good enough. The latest candidate to hit “good enough” is X(2370), which fell out of a collision in the Beijing Electron–Positron Collider II (BEPC II), as detected by the Beijing Spectrometer III (BES III). The paper hit ArXiv at the end of July. It’s taken the collaboration this long to make sure of what they were looking at, as they sorted through the terabytes of data an instrument like this generates.

Is this likely to affect you in any way? No. It confirms what we already thought we knew about the universe, and the particle itself is too short-lived to ever exist outside of some very extreme– mostly man-made– environments. On the other hand, it’s an excuse to celebrate scientific discovery, and we’ll take any of those we can, just like when the Muon Magnetic Moment measured in at the expected value, or neutrinos transmuted elements in exactly the way the models said they would. Besides, if we’re really lucky this result will turn out not to be a glueball, but something new and interesting. Then even the most jaded nerds will have reason to celebrate.

Header image: The Bejing III Spectrometer, BESII.

It’s likely many of us have been in the position of first set-up on a machine such as a Raspberry Pi, and had keyboard problems. Either no spare keyboard is to be found, or a cluttered desk has to find extra space for a full-size keyboard. [Henk] has a handy solution, use the existing keyboard on your laptop.

His approach is both ingenious and simple, as it’s only the K part of a KVM. On the laptop end, it’s a serial terminal, without the receiving side. The serial port in question is an RP2040 board which implements a USB-to-serial port. This serial connection goes to another RP2040, which does the ingenious bit. It’s a serial-to-USB HID keyboard. All of this means that keystrokes on the laptop are sent down the serial connection, and appear on the Pi or whatever computer as a USB keyboard as though typed locally. The mildly annoying first set-up can be done, and then it can be run via SSH or whatever other remote access protocol as normal. The code is provided, so anyone with a couple of RP2040 boards can do it.

We like this hack, because we’ve had the annoyance of needing a keyboard to set up what would otherwise be a completely headless machine too many times. It’s one to store away at the back of your mind, for those rare improvisational need-an-extra-keyboard moments.

One of the great things of Linux as an ecosystem is that there is so much choice. Yet this is also its greatest weakness, as unlike on MacOS and Windows this means that simple questions often do not have a simple answer. The topic of distributing software is one of these vexing topics that never really goes away, with [Noam Lewis], as author of the Fresh editor, recently expressing their frustrations on this topic.

This is a familiar topic that we have covered before, mostly in the context of cross-platform installers. Whereas on MacOS and Windows you just pick any of a handful of standard installer frameworks that do roughly the same thing, on Linux you are dealing with a dizzying number of package managers, including distro-specific ones, NPM, Homebrew, Rust crates, third party repositories like Arch Linux’s AUR or stray APT repositories for Debian, and of course AppImage and Flatpak along with a host of other options.

After going through the entire list with help from the Fresh community, [Noam] ended up creating packages for all of them, and has a lot of thoughts. Since Fresh is a TUI-based editor, something like Flatpack is not a really good fit, while AppImage is just very slow due to mounting the image, which is annoying.

Overall, distro-specific solutions are just unpleasant in general, as they mean repeating the same work over and over, even if you can even get into a distribution channel. Ultimately the solution that [Noam] ended up at was to have a static binary with the musl runtime, along with an integrated updater, which is a solution that should be quite familiar for Windows users. Yet even if it fails some kind of purity test for certain Linux users, is it really a bad solution if it works for users of the software?

Now that MCUs like the ESP32-S3 are quite capable computer systems including USB host functionality, it only makes sense that you can connect USB peripherals like Logitech racing wheels to them. Of course, these aren’t basic HID USB devices, so they require a bit of setup to make them start spitting out the data updates which we’re interested in. Making this process easy is the goal of the LogiWheelHost project for ESP32-S3 by [Joel Kometz].

This single-header library supports the G29, G923, G920, G27, G25, DFGT, Driving Force Pro wheels, building on top of the EspUsbHost project. As explained in the README, these racing wheels do not start streaming all updates to their controls once powered on, but boot into a restricted mode in which only neutral or combined-axis data is sent.

To change this you need to trigger the so-called native mode switch in which far more detailed information as well as updates on extended features like separate pedals, all buttons and the gear shifter become available. This is done by sending a HID output report to the USB device, which is easy enough.

In addition to handling this detail the library also provides an API using which obtaining and using these controller states in your own code should be quite easy. Presumably the library will work on or can be ported to other ESP32 MCUs that support host USB mode, so this might be good news for anyone who is looking to do more with that old Logitech racing wheel.

In this era of consumer-grade FDM printers that have automatic bed levelling, automatic pressure advance tuning, automatic temperature regulation and so on buttoned away behind bullet-proof presets and automation, something as archaic as manual filament tuning does seem a bit out of place. Unless you’re running that hot rod Voron FDM printer, does it make sense to ‘waste time’ with manual tuning your off-the-shelf FDM printer? In a recent video [MandicReally] argues that it still makes sense to unlock more performance.

Up front it’s made clear that these auto-tuned configurations are perfectly fine for the average user, who will be perfectly happy with something like a ‘generic PLA’ preset combined with whatever auto-configuration the printer did. That said, not every filament is the same, nor is each heating element, nozzle and feeding system. In that sense it can be worth it to take a deeper look.

In the video basic aspects like preparing the material, such as properly drying, are looked at, before running through tests for temperature, flow ratio and rate, pressure advance, retraction speeds, material shrinkage etc. before doing a test between such a tuned profile versus a generic preset for ASA filament.

Although the difference isn’t night and day, the tuned profile was faster due to less conservative settings and had better accuracy on the final print due to taking the target FDM printer’s performance into account. Even if not something that the average hobbyist would be interested in, if you’re doing something like production runs with FDM, this might be something you’d want to look at.

It’s no real secret that battery packs for power tools aren’t the foremost when it comes to user serviceability, so if said battery pack suddenly stops charging outside of warranty, you generally just e-waste it. That’s what [The Repair Forge] could have done for the Makita battery pack in question, but instead it was opened up for a diagnosis and fix.

Rather than the charger throwing up an error with this specific battery, it would flash its red LED and run its fan, but never actually start the charging process. Apparently the charger seems to think that the battery is either too hot or cold to be charged, which already gives a big hint as to what might be wrong.

Using the open source PocketOBI tool it’s possible to query the battery, which showed that one of the internal thermistors reported the battery being at a chilly -30°C while the other a more reasonable 28°C. After popping open the pack and measuring the thermistors, the faulty one registered as infinite resistance thus confirming that it had failed.

By putting in a temporary resistor this diagnosis was confirmed, thus the next step will be to replace said thermistor. This same procedure was then used with a second battery, whose thermistor read a wild 64°C.

Overall it’s a pretty easy fix, using a 20 cent part, with the entirety of diagnosis to repair taking maybe ten minutes when using a tool like PocketOBI, itself based on the great Open Battery Information project that originally reverse-engineered the Makita battery protocol.

Gears are usually the biggest contributors to backlash in a mechanical system, but they’re far from the only culprits. Ball bearings are a less obvious source of imprecision, since any gaps between the balls and the races can lead to axial wobble. Precision mechanisms can eliminate this by pairing two ball bearings, holding the outer races fixed, and applying a preload force to the inner traces. [Chronova Engineering], however, has a different solution, for which he split a ball bearing in half.

Besides taking up more room, thermal expansion also means that it’s difficult to apply a consistent preload force between two ball bearings. Instead, to make a self-contained preloaded bearing, [Chronova Engineering] first disassembled a single ball bearing. The most difficult part of this is taking apart the ball cage; the two parts of this are normally riveted together, but he managed to find a crimped cage and pry it apart. After taking the bearing completely apart, he cut the outer trace in half along the circumference, then reassembled the bearing. The split outer trace makes it possible to press the two halves together, preloading it and removing slop.

To see how well this worked, [Chronova Engineering] replaced the the ball bearing supporting one end of the feed screw for a milling machine with this new bearing. Before the replacement, it had a backlash of 0.1 to 0.2 millimeters; after the modification, it dropped to 30 to 40 microns. This kind of bearing is already known in the machining world – four-point-contact bearings use a very similar principle – but they don’t seem to be well known.

For more about these common yet remarkable rotary mechanisms, check out our article on bearings. If, on the other hard, precision isn’t a priority, you can always 3D print ball bearings.