iranifilm sexi[Kryzer Channel] takes making a DIY RC car to a whole new level with this prop-driven electric car that is made almost entirely out of cardboard (YouTube video, also embedded below.) By attaching an electric motor with a push prop to the back of the car, [Kryzer] avoids the need for any kind of drive system or gearing. Steering works normally thanks to some scratch-built linkages, but the brake solution is especially clever.
iranifilm sexiBraking is done by having a stocky servo push a reinforced stub downward, out of a hole in the center of the car. This provides friction against the road surface. After all, on an RC car a functional brake is simply not optional. Cutting the throttle and coasting to a stop works for a plane, but just won’t do for a car.
Layers of corrugated cardboard and hot glue make up the bulk of the car body, and some of the assembly techniques shown off are really slick and make the video really worth a watch. For example, the construction of the wheels (starting around 2:24) demonstrates making them almost entirely out of cardboard, saturated with CA glue for reinforcement, with a power drill acting as a makeshift lathe for trimming everything down. A section of rubber inner tube provides the tire surface and a piece of hard plastic makes a durable hub. Wraps of thread saturated in CA glue, shown here, is another technique that shows up in several places and is used in lieu of any sort of fasteners.
How does it work? When a monitor can’t attach directly to a VESA mount, this assembly attaches to the mount instead. The three arms extend around the edge of the monitor to grip it from the bottom and top. Some hex-head M5 bolts and nuts are all that are required to assemble the parts, and the top arm is adjustable to accommodate different sizes of monitor. As long as the screen size is between 17 and 27 inches diagonal, and the monitor thickness falls between 30 mm and 75 mm, it should fit.
Its well-insulated plywood walls let him mount monitor arms and just about anything else anywhere he wants, and the solar power system allows him to work all day (and into the night if he wants, which he doesn’t) except for a few spells in the winter where sunlight is just too scarce and a generator picks up the slack. Most importantly, it provides a solid work-life separation — something [Russell] is convinced is critical to basic wellness as a human being.
That’s not to say an off-grid solar shed is the perfect solution for everyone. Not everyone can work from home, but for those who can and who identify with at least some of the motivations [Russell] expressed when we covered how he originally created his office shed, he encourages giving it some serious thought.
The only thing he doesn’t categorically recommend is the off-grid, solar powered part. To be clear, [Russell] is perfectly happy with his setup and even delights in being off-grid, but admits that unless one has a particular interest in solar power, it makes more sense to simply plug a shed office into the grid like any other structure. Solar power might seem like a magic bullet, but four years of experience has taught him that it really does require a lot of work and maintenance. Determined to go solar? Maybe give the solar intensity sensor a look, and find out just how well your location is suited to solar before taking the plunge.
It’s been just over a year since Valve released Index, their flagship VR system, and it’s worth looking back at this GitHub repository as a fine example of how to provide supporting materials to a hacker-friendly hardware design. The image above shows off one of the hacker-friendly design elements: an empty space behind the visor, with a USB port off to the right, that exists for no reason other than to make it easier to mount and plug in whatever one might come up with. There’s more to it than that, however. If one wishes to provide supporting materials for a hardware design, one could certainly do worse than emulate Valve’s example.
The hardware repository contains not just CAD models of mod-friendly hardware pieces (both in high-resolution STEP models as well as STL files) but also 3D models of the sensor zones, so modders can ensure they avoid occluding any sensors with their creations. Examples are great, and one provided by Valve is the Booster; a hand controller add-on providing extra comfort for people with large hands or long thumbs. The model also doubles as a reference for designing attachments that will not interfere with any of the tracking or touch-sensitive surfaces of the controllers.
Being hacker-friendly doesn’t mean the hardware has no warranty, but it does mean that there is concrete guidance on what does or doesn’t risk voiding it. In the case of the Index hardware, the guidance is simple: “Anything that requires a T5 or smaller is not user serviceable.”
[Chris Mullins] wanted to automate opening and closing the slats of mini blinds in his apartment, and came up with a system to do it as a fun project. Manually opening and closing the slats means twisting a rod. Seems straightforward to automate that, but as usual when having to work around something that already exists, making no permanent alterations, complications arose.
The blinds are only 1 inch wide, leaving little room for mounting any sort of hardware. While there is a lot of prior art when it comes to automating blinds, nothing he found actually fit the situation [Chris] had, so he rolled his own.
The rod that is normally twisted to control the blinds is removed, and the shaft of a stepper motor takes its place. [Chris]’ mounting solution is made to fit blinds with narrow 1 inch tracks (existing projects he found relied on 2 inch tracks) and the 3D printed mount is fully adjustable, so the 28BYJ stepper motor can be moved into exactly the right position. Speaking of the stepper motor, the 28BYJ motor is unipolar but the A4988 driver he wanted to use is for bipolar steppers only. Luckily, cutting a trace on the motor’s PCB is all it takes to turn a unipolar motor into bipolar.
To drive the motor and provide wireless functionality, the whole thing works with a Wemos D1 ESP8266, an A4988 stepper driver, and a buck converter. While it worked fine as a one-off on a perfboard, [Chris] used the project as an opportunity to learn how to make a PCB using KiCad; the PCB project is here on GitHub and the ESP8266 runs the ESPHome firmware. Be sure to check out the project page on his blog for all the details; [Chris] links to all the resources there, and covers everything from a bill of materials to walking through configuration of ESPHome with integration into the open-source Home Assistant?project.
Looking to control natural light but blinds aren’t your thing? Maybe consider automated curtains.
Cameras are getting smarter and more capable than ever, able to run embedded machine vision algorithms and pull off tricks far beyond what something like a serial camera and microcontroller board would be capable of, and the upcoming Vizy aims to be even smarter and easier to use yet. Vizy is the work of Charmed Labs, and this isn’t their first foray into accessible machine vision. Charmed Labs are the same folks behind the Pixy and Pixy 2 cameras. Vizy’s main goal is to make object detection and classification easy, with thoughtful hardware features and a browser-based interface.
The usual way to do machine vision is to get a USB camera and run something like OpenCV on a desktop machine to handle the processing. But Vizy leverages a Raspberry Pi 4 to provide a tightly-integrated unit in a small package with a variety of ready-to-run applications. For example, the “Birdfeeder” application comes ready to take snapshots of and identify common species of bird, while also identifying party-crashers like squirrels.
The demonstration video on their page shows off using the built-in high-current I/O header to control a sprinkler, repelling non-bird intruders with a splash of water while uploading pictures and video clips. The hardware design also looks well thought out; not only is there a safe shutdown and low-power mode for the Raspberry Pi-based hardware, but the lens can be swapped and the camera unit itself even contains an electrically-switched IR filter.
[Petar Crnjak]’s Faze4 is a open source robotic arm with 3D printable parts, inspired in part by the design of industrial robot arms. In particular, [Petar] aimed to hide wiring and cables inside the arm as much as possible, and the results look great! Just watch it move in the video below.
Cycloidal gearboxes have been showing up in robotic arm projects more and more, and Faze4 makes good use of them. Why cycloidal gears? They are readily 3D printed and offer low backlash, which makes them attractive for robotic applications. There’s no need to design cycloidal gears from scratch, either. [Petar] found this cycloidal gear generator in OnShape extremely useful when designing Faze4.
The project’s GitHub repository has all the design files, as well as some video demonstrations and a link to assembly documentation for anyone who would like to make their own. Watch Faze4 go through some test movements in the video embedded below.