Terry Pratchett once wrote, “In ancient times cats were worshipped as gods; they have not forgotten this”. [Jonathan]’s cat has clearly not forgotten, and makes it loudly known whenever her favorite chair needs to be moved to stay in the spot of sunlight. He was looking for a fun hack anyway, so he decided to give in to her majesty’s demands, and automated the task.
[Jonathan] first considered adding motorizing the chair itself, but decided to keep it simple and just drag the chair across the room with a spool attached to a motor. The rope spool was attached to a small geared DC motor, mounted on a salad bowl base, and connected to an ESP8266 via a motor driver. The ‘8266 is running NodeMCU with a web server that accepts simple motor commands through a RESTful API. This setup can’t reset the chair to it’s starting position at the end of the day, but this is a small price to pay for simplicity. The motor was a bit underpowered, but it only needed to move the chair in small distances at a time, so [Jonathan] removed the chair’s back to reduce the weight, and upped the motor voltage.
Determining when and how far to move the chair is the second part of the challenge. [Jonathan] considered a simple lookup table for the time of day, but the motor’s movement wasn’t consistent enough. The final solution was a set of three BH1750 digital ambient light sensors to give feedback. A pair of sensors on the chair determines its position relative to the sunny spot, by comparing light levels to a reference sensor mounted in the window. These light sensors are also attached to NodeMCUs, and send movement commands to the winding unit as necessary.
If you move as a hardware hacker through the sometimes surprisingly similar world of artists, craftspeople, designers, blacksmiths, and even architects, there’s one piece of work that you will see time and time again as an object that exerts a curious fascination. It seems that designing and building a chair is a rite of passage, and not just a simple chair, but in many cases an interesting chair.
Some of the most iconic seating designs that you will be instantly familiar with through countless mass-produced imitations began their lives as one-off design exercises. Yet we rarely see them in our community of hackers and makers, a search turns up only a couple of examples. This is surprising, not least because there is more than meets the eye to this particular piece of furniture. Your simple seat can be a surprisingly complex challenge.
Moving Charis From Artisan to Mass Market
The new materials and mass production techniques of the 19th and 20th centuries have brought high-end design into the hands of the masses, but while wealthy homes in earlier centuries had high-quality bespoke furniture in the style of the day, the traditional furniture of the masses was hand-made in the same way for centuries often to a particular style dependent on the region in which it was produced.
The 1960s were a heady time, with both society and the language of design undergoing rapid changes over a short period. Back in 1968, Henrik Thor-Larsen exhibited his Ovalia egg chair for the first time, at the Scandinavian Furniture Fair. With original examples now antiques, and with even replicas being prohibitively expensive, it might just be worth considering building your own if you need to have one. Thankfully, [Talon Pascal] leads the way.
It’s a replica that’s built with accessible DIY tools and techniques. The frame is built up from plywood parts, cut out with a jigsaw. These are then assembled with glue and screws, forming two halves of the full-sized egg assembly. The exterior is then covered with thin strips of wood, as opposed to the fiberglass construction of the original. This is smoothed out with a judicious application of wood putty and plenty of sanding. The interior is then lined with foam before the chair is upholstered with red fabric. We’re not sure exactly how the trim ring is fitted, but it gives the chair a nice clean finished edge and rounds out the project nicely. There are even embedded speakers so you can chill out with some tunes in your ovaloid sanctuary.
The Flite Test crew is well known for putting some crazy flying contraptions together. They’ve outdone themselves this time with a flying IKEA chair. This build began with [Josh] issuing a challenge to [Stefan]. Take a standard IKEA ladderback chair and make it fly– in less than six hours. With such a tight schedule, measuring twice and cutting once was right out the window. This was a hackathon-style “throw it together and hope it works” build.
The chair was plenty sturdy, so it became the core of the fuselage. [Stefan] grabbed the wing from a previous plane and placed it on the seat of the chair. Two carbon fiber rods drilled into the seat frame formed a tail boom. The tailfeathers were built from Flite Test foam – paper coated foam-core board.
With the structure complete, [Stefan] and his team added servos for control, a beefy motor for power, and some big LiPo batteries. The batteries hung from the bottom of the chair to keep the center of gravity reasonable.
When the time came for the maiden flight, everyone was expecting a spectacular failure. The chair defied logic and leaped into the air. It flew stable enough for [Josh] to take his fingers off the sticks. The pure excitement of seeing a crazy build that works is on full display as the entire Flite Test crew literally jumps for joy. [Alex] even throws in a cartwheel. This is the kind of story we love to cover here at Hackaday – watching a completely nutty build come together and perform better than anyone expected.
Although it might be more accurate to say that this chair dances because no one is watching, the result is still a clever project that [Igor], a maker-in-residence at the National Museum of Decorative Arts and Design in Norway, created recently. Blurring the lines between art, hack, and the ghosts from Super Mario, this chair uses an impressive array of features to “dance”, but only if no one is looking at it.
In order to get the chair to appear to dance, [Igor] added servo motors in all four legs to allow them to bend. A small non-moving dowel was placed on the inside of the leg to keep the chair from falling over during all of the action. It’s small enough that it’s not immediately noticeable from a distance, which helps maintain the illusion of a dancing chair.
From there, a Raspberry Pi 3 serves as the control center for the chair. It’s programmed in Python and runs OpenCV for face detection and uses pigpio for controlling the leg servos. There’s also a web interface for watching the camera’s output and viewing its facial recognition abilities. The web interface also allows a user to debug the program. [Igor]’s chair can process up to 3 frames per second at 800×600 pixels.
Be sure to check out the video after the break to see the chair in action. It’s an interesting piece of art, and if those dowels can support the weight of a person it would be a great addition to any home as well. If it’s not enough chair for you, though, there are some other more dangerous options out there.
[masterfoo]’s mother-in-law suffers from a bad hip which would have sidelined her participation in the Fourth of July festivities. As a testament to the power of family and ingenuity, [masterfoo] built her a beach-capable wheel chair to give her some off-roading capability.
The frame is built out of 1.5″ PVC piping and the tires are 20×8-8″ inner tubes for ride-on lawnmowers. The lawnmower wheel inner tubes were cost-effective and fit the purpose, saving the need for the more expensive purpose-built-for-the-beach Wheeleez tires. They also have a fluid inside that plugs small punctures which will come in handy against he beach’s small cacti and other flora. This video was their guide for the foam insulation and plywood wheel assembly, also employing the handy man’s secret weapon to protect the tube from the rim’s plywood edge. Check it out in action!
A PS-3 controller has an unbalanced motor inside that vibrates your hand whenever you crash a car into a wall or drive it off a cliff and hit the rocks below but [Rulof Maker] wanted that same feeling all over his body. So he added a serious unbalanced motor to his favorite gaming chair to make his whole body vibrate instead.
To do that he opened up the controller and found the wires going to the unbalanced motor. There he added a small relay, to be activated whenever the motor was energized. Wires from that relay go to a female connector mounted in the side of the controller, keeping the controller small and lightweight.
Next he needed to attach a much bigger unbalanced motor to the underside of his favorite gaming chair. For the unbalanced mass he poured concrete powder and molten lead into a tin can mold and attached the result to the motor’s shaft. Using a piece of wood he attached the motor to the chair’s underside.
All that was left was to power the motor and turn it on when needed. For that he wired up a bigger relay, with the relay’s coil wired to a male connector to plug into the PS-3 controller. Now when the PS-3 wants to vibrate, that relay is energized. All that was left was to wire the relay’s normally open switch, the motor and a power cord in series, plug it into the wall socket, and he was ready to shake.