The mechanical keyboard community is a vibrant, if not fanatical, group of enthusiasts determined to find as many possible ways of assembling, building, and using as many high-quality keyboards as possible. With so many dedicated participants, most things that can be done with a keyboard already have been done. So when something as unique as this split keyboard that also doubles as a mouse pops up, we take notice.

The keyboard is a custom build from [Taliyah Huang] which uses a pair of Arduinos, one in each half of the keyboard, to communicate key and mouse information to a third Arduino which is plugged in to her laptop. The right-hand half of the keyboard also includes the circuitry from an optical mouse, which gets powered up when the caps lock button is held down. When activated, this allows the keyboard to be used as a mouse directly. It also includes support for most Mac gestures as well, making it just as useful as a trackpad.

While there were some problems with the design, including being slightly too tall to be ergonomic and taking nearly 24 hours of soldering to complete, the prototype device is an interesting one especially since it allows for full control of a computer without needing a dedicated mouse. For other unique mechanical keyboard concepts, we recently featured this build which takes design and functionality cues from the Commodore 64.

For those unfamiliar with the details of the expansive work of fiction of Harry Potter, it did introduce a few ideas that have really stuck in the collective conscious. Besides containing one of the few instances of time travel done properly and introducing a fairly comprehensive magical physics system, the one thing specifically that seems to have had the most impact around here is the Weasley family clock, which shows the location of several of the characters. We’ve seen these built before in non-magical ways, but this latest build seeks to drop the price tag on one substantially.

To do this, the build relies on several low-cost cloud computing solutions and smartphone apps to solve the location-finding problem. The app is called OwnTracks and is an open-source location tracker which can report data to any of a number of services. [Simon] sends the MQTT data to a cloud-based solution called HiveMQCloud, but you could send it anywhere in principle. With the location tracking handled, he turns to some very low-cost Arduinos to control the stepper motors which point the clock hands to the correct locations on the face.

While the build does rely on a 3D printer for some of the internal workings of the clock, this does bring the cost down substantially when compared to other options. Especially when compared to this Weasley family clock which was built into a much larger piece of timekeeping equipment, having an option for a lower-cost location-tracking clock face like this one is certainly welcome.

LED and LCD displays are a technological marvel. They’ve brought the price of televisions and monitors down to unheard-of levels since the days of CRTs, but this upside arguably comes with an aesthetic cost. When everything is covered in bland computer screens, the world tends to look a lot more monotonous. Not so several decades ago when there were many sharply contrasting ways of displaying information. One example of this different time comes to us by way of this split-flap display that [Erich] has been recreating.

Split-flap displays work by printing letters or numbers on a series of flaps that are attached to a spindle with a stepper motor. Each step of the motor turns the display by one character. They can be noisy and do require a large amount of maintenance compared to modern displays, but have some advantages as well. [Erich]’s version is built out of new acrylic and MDF, and uses an Arduino as the control board. A 3D printer and CNC machine keep the tolerances tight enough for the display to work smoothly and also enable him to expand the display as needed since each character display is fairly modular.

Right now, [Erich]’s display has 20 characters on two different rows and definitely brings us back to the bygone era where displays of this style would have been prominent in airports and train stations. This display uses a lot of the basics from another split flap display that we featured a few years ago but has some improvements. And, if you’d prefer restorations of old displays rather than modern incarnations, we have you covered there as well.

Thanks to [Bob] for the tip!

A 3D printer is a wonderful invention, but it needs maintenance like every machine that runs for long hours. [Rob Ward] had a well-used Robox 3D printer that was in need of some repairs, but getting the necessary replacement parts shipped to Australia was cost-prohibitive. Rather than see a beloved printer be scrapped as e-waste, he decided to rebuild it using components that he could more easily source. Unfortunately the proprietary software and design of the Robox made this a bit difficult, so it was decided a brain transplant was the best path forward.

Step one was to deduce how the motors worked. A spare RAMPS 1.4 board and Arduino Mega2560 made short work of the limit switches and XYZ motors. This was largely accomplished by splicing into the PCBs themselves. The Bowden filament driver motor had a filament detector and an optical travel sensor that required a bit of extra tuning, but now the challenging task was next: extruding.

With a cheap CR10 hot end from an online auction house, [Rob] began modifying the filament feed to feed in a different direction than the Robox was designed for (the filament comes in at a 90-degree angle on the stock Robox). A fan was needed to cool the filament feed line. Initial results were mixed with lots of blockages and clogs in the filament. A better hot end and a machined aluminum bracket for a smoother path made more reliable prints.

The original bed heater was an excellent heater but it was a 240 VAC heater. Reluctant to having high voltages running through his hacked system, he switched them out for 12 VDC adhesive pads. A MOSFET and MOSFET buffer allowed the bed to reach a temperature workable for PLA. [Rob] upgraded to a GT2560 running Marlin 2.x.x.

With a reliable machine, [Rob] stepped back to admire his work. However, the conversion to the feed being perpendicular to the bed surface had reduced his overall build height. With some modeling in OpenSCAD and some clever use of a standard silicone sock, he had a solution that fed the wire into the back of the hot end, allowing to reclaim some of the build height.

It was a long twelves months of work but the write-up is a joy to read. He’s included STL and SCAD files for the replacement parts on the printer. If you’re interested in seeing more machines rebuilt, why not take a look at this knitting machine gifted with a new brain.

[Emiel] aka [The Practical Engineer] makes all kinds of fun projects in his fully-featured shop, and one of his tangents has been building a series of solenoid engines. These engines mimic the function of an internal combustion engine, with each solenoid acting as a piston. The only problem with [Emiel]’s concept engines, though, was that he never actually put them into a vehicle to prove their effectiveness. This build finally proves that they can work at powering a vehicle.

The project starts with a new engine. [Emiel] chose a V4 design using four solenoids and an Arduino-based controller. After some trouble getting it to operate properly, he scavenged a small circuit board he built in his V8 solenoid engine to help with timing. With that installed, the solenoids click away and spin the crankshaft at a single constant speed. The vehicle itself was mostly 3D printed, with two aluminum tubes as support structures to mount the engine. Even the wheels were 3D printed with a special rubber coating applied to them. With a small drive train assembled, it’s off to the races for this tiny prototype.

While the small car doesn’t have steering and only goes at a constant speed, the proof of concept that these tiny electric engines actually work is a welcomed addition to [Emiel]’s collection of videos on these curious engines. Of course they’re not as efficient as driving the wheels directly with an electric motor, but we all know there’s no fun in that. If you haven’t seen his most intricate build, the V8 is certainly worth checking out, and also shows off the timing circuitry he repurposed for this car.

3D printers are an excellent tool to have on hand, largely because they can print other tools and parts rapidly without needing to have them machined or custom-ordered. 3D printers have dropped in price as well, so it’s possible to have a fairly capable machine in your own home for only a few hundred dollars. With that being said, there are some limitations to their function but some of them can be mitigated by placing the printer head on a robot arm rather than on a traditional fixed frame.

The experimental 3D printer at the University of Nottingham adds a six-axis robotic arm to their printer head, which allows for a few interesting enhancements. Since the printer head can print in any direction, it allows material to be laid down in ways which enhance the strength of the material by ensuring the printed surface is always correctly positioned with respect to new material from the printer head. Compared to traditional 3D printers which can only print on a single plane, this method also allows for carbon fiber-reinforced prints since the printer head can follow non-planar paths.

Of course, the control of this printer is much more complicated than a traditional three-axis printer, but it is still within the realm of possibility with readily-available robotics and microcontrollers. And this is a hot topic right now: we’ve seen five-axis 3D printers, four-axis 3D printers, and even some clever slicer hacks that do much the same thing. Things are finally heating up in non-planar 3D printing!

Thanks to [Feinfinger] for the tip!

A set of helping hands is a nice tool to have around the shop, especially if soldering or gluing small components is a common task. What we all really want, though, is a robotic arm. Sure, it could help us set up glue or solder but it can do virtually any other task it is assigned as well. A general-purpose tool like this might be out of reach of most of us, unless we have a 3D printer to make this open-source robotic arm at home.

The KAUDA Robotic Arm from [Giovanni Lerda] is a five-axis arm with a gripping tool and has a completely open-source set of schematics so it can be printed on any 3D printer. The robot arm uses three stepper motors and two servo motors, and is based on the Arduino MEGA 2560 for control. The electrical schematics are also open-source, so getting this one up and running is just an issue of printing, wiring, and implementing some software. To that end there are software examples available, and they can easily be modified to fit one’s robotic needs.

A project like this could be helpful for any number of other projects, or also just as a lesson in robotics for yourself or even in a classroom, since many schools now have their own 3D printers. With everything being open-source, this is a much simpler endeavor now than other projects we’ve seen that attempted to get robotic arms running again.

Heavy duty coffee makers are good for, well, making coffee. On the other hand, if you were to look at the frame without the preconception of what it can do, you might notice that there is space on top where equipment could be attached, and space on the bottom with a built-in heating pad on which to place an object… in other words, a perfect 3D printer frame!

Tropical Labs realized this, and turned the ordinary household appliance into a delta printer with three steppers for motion and another to feed the printing media. An Arduino Mega serves as the brains of the operation along with a popular RAMPS 1.4 shield.

Frame aside, it’s a neat mechanism, and definitely worth checking out. You can see more about the project on Hackaday.io.

To “pipe in” the new year, [John] decided to build a bagpipe-playing robot. Unlike other instrument-playing robots that we’ve seen before, this one is somewhat anatomically correct as well. John went the extra mile and 3D printed fingers and hands to play his set of pipes.

The brains of the robot are handled by an Arduino Mega 2560, which drives a set of solenoids through a driver board. The hands themselves are printed from the open source Enabling the Future project which is an organization that 3D prints prosthetic hands for matched recipients, especially people who can’t otherwise afford prosthetics. He had to scale up his hands by 171% to get them to play the pipes correctly, but from there it was a fairly straightforward matter of providing air to the bag (via a human being) and programming the Arduino to play a few songs.

The bagpipe isn’t a particularly common instrument (at least in parts of the world that aren’t Scottish) so it’s interesting to see a robot built to play one. Of course, your music-playing robot might be able to make music with something that’s not generally considered a musical instrument at all. And if none of these suit your needs, you can always build your own purpose-built semi-robotic instrument as well.

We watched the video introduction for this little open source robot, and while we’re not 100% sure we want tiny glowing eyes watching us while we sleep, it does seem to be a nice little platform for hacking. The robot is a side project of [Matthew], who’s studying for a degree in Information Science.

The robot has little actuated grippy arms for holding a cell phone in the front. When it’t not holding a cellphone it can use its two little ultrasonic senors to run around without bumping into things. We like the passive balancing used on the robot. Rather than having a complicated self-balancing set-up, the robot just uses little ball casters to provide the other righting points of contact.

The head of the robot has plenty of space for whatever flavor of Arduino you prefer. A few hours of 3D printing and some vitamins is all you need to have a little robot shadow lurking in your room. Video after the break.