There are all kinds of avenues into the mechanical keyboarding hobby, and one of the more well-traveled ones runs between coworkers. [crsayen] aka [DrJamesOIncandenza] has one such relationship, and was turned on to the CRKBD a while back by an office mate. For the uninitiated, that’s short for Corne keyboard, which is a column-staggered 3×6 split keyboard with three thumb keys per hand.
While [JOI] liked the Corne well enough, especially with chocs, he got the occasional craving to slap (that’s what we’re calling typing on linears from now on — slapping vs. clacking) on some silent MX switches and so built this Corne-derivative monoblock split called Keyboard One. Aside from the more obvious differences,
We think this looks rather spanking for a first keyboard, sort of like a slightly smaller Alice or something. But you don’t have to go to great lengths to obtain [JOI]’s knowledge, for everything is on GitHub. [JOI] says they sort of regret going 3×6, but are already planning another build with more keys. See, that’s the spirit.
The more people we have on this planet, the more food we need. Naturally, this extends to water, another precious resource that generally plays a part in farming and food production. And honestly, we’d probably all eat a little better if it were really easy to grow healthy things like spinach. Well, that excuse doesn’t work anymore, thanks to [J Gleyzes]’ Ultratower. It’s a simple-to-use hydroponic tower that uses recycled mist to water plants, ultimately saving water in the process.
The ‘ultra’ part is a function of the way mist is created. In this case, it’s done with three piezoelectric disks mounted under a tank in the top of the PVC tube. Stick up to twelve plants in the little cubbies, and their roots will grow down the inside, where they’ll receive a fine shower of water at your command. Water that runs off the roots collects in a small tank at the bottom, where a pump starts the process over again.
At first, [J Gleyzes] had trouble with the piezo disks — using 1.7MHz disks created too much heat, warming the water up to nearly 40°C (104°F). Since cooking the spinach prematurely would be bad, they experimented with other values, finally landing on 108KHz. Be sure to check out the video after the break.
Bike frames are simple on the surface, but can quickly become complicated if you want to fabricate one yourself. Brazing and welding tend to be less common skills than knowing how to bolt things together, so [Arquimaña] has brought us the OpenBike to make the process accessible to more people.
An open-source set of files designed for CNCs and 3D printers, the OpenBike uses readily available materials like sheet plywood to make a sturdy, if unconventional-looking, bicycle. Like many other consumer goods, most bike frames are currently built in Asia. This allows for economies of scale, but removes locals from the design process. By using simpler tools, OpenBike allows for more local direction of what features might be needed for a particular region.
Shifting even a small portion of trips to more active forms of transport is an important part of lowering carbon emissions, so making bikes a more attractive means of transportation is always welcome. What might be important in one region might be superfluous and expensive in another (multiple gears in a hilly region, for example). OpenBike could be especially useful as a way to rapid-prototype different feature sets for a particular region before committing to a more traditional frame-building technique for larger batches of bikes.
Many of us will have the problem of several computers on the same desk, and to avoid clutter we’ll use a KVM switch to share the peripherals. [The Turbanned Engineer] has an interesting solution to this problem in the form of a USB triplexer. It’s a device that routes USB data lines depending upon which of its connections is powered up.
The circuit is simple enough: a CMOS analogue multiplexer does the routing, and a set of opto-couplers do the selecting based on the power inputs. A set of USB A sockets connect to the computer, and a USB B socket connects to the peripheral.
We’re not entirely sure whether an analogue multiplexer chip would be good for the higher-speed USB data rates, but since keyboards and mice talk at the slowest data rates, we think he’ll get away with it. Either way making a USB switch however basic with such mundane components has something of the hack about it. What he does with the display we’re not so sure about, but at least his keyboard and mouse woes are dealt with.
Have you ever considered building your own telescope? Such a project can be daunting, especially if you grind your own mirrors. But with a 3D printer, hardware store bits and bobs, and some inexpensive pre-made mirrors, you too can be the proud owner of your very own own Hadley — a 900mm Newtonian Telescope that can cost less than $150 USD to build! Check out the video below the break to get a good scope on the project.
The creator’s stated goal is to “make an attractive alternative to the shoddy, hard to use “hobby-killer” scopes in the $100-200 range“, and we have to say that it appears to have met its goal admirably. The optics — the most complex part of any build — can be easily purchased online, and the rest of the parts are available at your local hardware store.
While the original build was provided in Imperial measures, a metric version is now available. Various contributors have created a rich ecosystem of accessories and alternative versions of various parts, all in the interest of making the telescope more useful. Things like tripod mounts, phone mounts (for use with your favorite star chart app) and more are only a click away. The only real question to answer is “What color filament will I use?”
[MirageC] is a bit of a contrarian. Instead of taking pictures of 3D printed objects that show them in their best light, he takes pictures that show them at their worst. The reason? He wanted to figure out why he was seeing a strange artifact in his printer when using a direct extruder. Just at a quick glance, you might think the problem was Z wobble, but, in this case, it was something else. You can see the fine detective work in the video below.
There were a few odd things about the problem. First, it scaled with the part size. Secondly, the problem got better when he switched to a Bowden tube setup. We don’t want to give away the ending, but you can guess from that clue that the problem had something to do with the extrusion system.
The resulting analysis led [MirageC] to work with BMG to create a special gear which — surprisingly, didn’t help as much as he thought it would. However, it did help point the way to the correct solution.
Along the way, you can learn a lot from following along, and maybe you’ll even improve the quality of your prints. We always enjoy these detailed analyses of printer issues, like the ones from [Stefan], for example. If you want to go hardcore engineering on your 3D prints, you can always do finite element analysis on your infill.
The security world held our collective breaths early this week for the big OpenSSL vulnerability announcement. Turns out it’s two separate issues, both related to punycode handling, and they’ve been downgraded to high severity instead of critical. Punycode, by the way, is the system for using non-ASCII Unicode characters in domain names. The first vulnerability, CVE-2022-3602, is a buffer overflow that writes four arbitrary bytes to the stack. Notably, the vulnerable code is only run after a certificate’s chain is verified. A malicious certificate would need to be either properly signed by a Certificate Authority, or manually trusted without a valid signature.
A couple sources have worked out the details of this vulnerability. It’s an off-by-one error in a loop, where the buffer length is checked earlier in the loop than the length variable is incremented. Because of the logic slip, the loop can potentially run one too many times. That loop processes the Unicode characters, encoded at the end of the punycode string, and injects them in the proper place, sliding the rest of the string over a byte in memory as a result. If the total output length is 513 characters, that’s a single character overflow. A Unicode character takes up four bytes, so there’s your four-byte overflow. Continue reading “This Week In Security: OpenSSL Fizzle, Java XML, And Nothing As It Seems”→