A multi-colored chair with a stainless steel frame sits on wooden legs against a grey background.

Recycled Chairs Bring The Subway To Your Living Room

Public transit seats have a rough life. Enduring a number of wear cycles that would make your sofa weep, they take a beating and have to keep looking presentable. When trains and buses are retired, where do the old seats go? A team from the MIT Hobby Shop investigated what was happening to the seats from retiring MBTA Red Line cars and recycled them into stylish chairs.

After some sleuthing and many emails, the MBTA relinquished a number of old subway seats to the team. Since the subway seats didn’t have legs, wood from old church pews was used to create bases. It took one pew end support to create each set of legs, which were cut out on a bandsaw. The old dark stain was sanded off, and the bases were finished with three coats of gel topcoat, letting the natural beauty of the old oak shine through.

We love seeing old things given new life here at Hackaday. If you want to see some more recycled furniture, check out this tire table, this upcycled jeans chair, or these best practices for making box forts.

A blue cabinet. Inside, along the front and back are wooden sawteeth holding a cleat. On the cleat sits the shelf itself.

Adjusting Shelves Like It’s 1899

In most modern homes, any adjustable shelves or cabinets have metal shelf pins set inside conveniently spaced holes. Before the accoutrements of modern life, like easily replicated metal parts, you may have found a sawtooth shelf doing the same job with just wood.

The system comprises three parts: a series of “sawteeth” running up and down the front and back edge of a cabinet, a cleat to sit between the teeth, and a shelf with notched corners that can then be set down on the cleats on either side.

While not as convenient as running a drill through a shelf pin jig, this method has a certain charm and sturdiness that isn’t present in more modern methods of making adjustable shelves. We can see this being particularly useful for restoration projects of homes from the 19th Century or earlier where you want some of those aforementioned accoutrements without things looking too anachronistic.

If you want some shelving that’s decidedly more 21st Century, check out this MP3 Player Shelf or this Smart Shelf with Serious Functionality.

Infrastructure diagram of [Stefan]'s network at the end of his fiber optics journey

Say No To Obsolescence, Wire Up Your House With Fiber

These days, if you wire your house with anything less than gigabit, you might end up throttling your Internet connection. If you wired things up using two pairs per device back in 100BASE-T days, however, you’ll want to redo your cabling before you buy new switches. Now, some of us are already starting to equip ourselves with 2.5G hardware — which may require new cabling once again. Would you like to opt out of the Ethernet cabling upgrade rat race, at least for a while? Do like [Stefan Schüller] did, and use fiber optics for your home networking needs!

[Stefan] walks you through everything you’d need to know if you ever choose to look into fiber for your networking needs, and explains the design decisions he’s made — from splicing fiber optics himself, to building a PC to do routing instead of getting a hardware Small Form-factor Pluggable (SFP) equipped router. He also describes pitfalls, like SFP modules requiring reconfiguration to work with different router brands, and having to buy a fiber splicer with an eye-watering pricetag.

In the end, he shows a cost breakdown, and says he’s quite happy with the upgrade. While the costs might seem prohibitive compared to running Ethernet, upgrading to fiber will have your equipment function at top speed whenever you need it – who knows, perhaps in a few years time, 2.5G will no longer suffice for new advancements in home technology needs, and we’ll see more SFP modules in hackers’ hands. After all, modern TVs already use fiber optics for video data transfer.

Continue reading “Say No To Obsolescence, Wire Up Your House With Fiber”

Simple Wi-Fi Cat Door Solves The Extra Critter Problem, And Nothing More

Anyone with an outdoor cat in their life knows their propensity for bringing home offerings, in the form of critters in various stages of the process of becoming ex-critters. And anyone with a hacker in their life knows that there’s a tendency to throw technology at this problem. But sometimes, the simplest solutions are the best.

Take this simple stepper-powered cat door lock. For [Jason Winfield], the essential problem with his outdoor cat’s late-night demands for reentry was having to manually unlock the cat door after a quick visual check that no midnight snacks were along for the ride. Such activity tends to make it hard to get back to sleep. One natural reaction to this would be to completely automate the process with machine learning to recognize the offering and deny entry; we’ve seen exactly that before, after all. But recognizing that the disruptive part was the getting up to check bit, [Jason] just whipped up a simple stepper-driven lock with an ESP8266 microcontroller. With a 3D-printed case and a battery pack, and a nearby Wi-Fi camera, the lock denies entry to the cat until he gets a look at it, at which point he simply hits the lock’s webpage to unlock the door. The video below would show the lock in action, except the cat buggered off once it got a whiff of the doings. Cat’s gonna cat.

What we appreciate about this project is its simplicity. It solves the problem with the minimum feature set, which is something we see too little of sometimes. It’s also got some nice ideas, like the non-captive bolt that can be removed to unlock the door if the battery dies. Smart thinking, [Jason], and sweet dreams.

Continue reading “Simple Wi-Fi Cat Door Solves The Extra Critter Problem, And Nothing More”

Breakers for the system on a DIN rail, with markings like 48V and 24V and 12V and so on on the bottom, and two hefty devices of some kind on the bottom, probably MPTT controllers, with hefty wires running from them.

Low-Voltage DC Network Build Incited By Solar Panels

Nowadays, some people in Europe worry about energy prices climbing, and even if all the related problems disappear overnight, we’ll no doubt be seeing some amounts of price increase. As a hacker, you’re in a good position to evaluate the energy consuming devices at your home, and maybe even do something about them. Well, [Peter] put some solar panels on his roof, but couldn’t quite figure out a decent way to legally tie them into the public grid or at least his flat’s 220V network. Naturally, a good solution was to create an independent low-voltage DC network in parallel and put a bunch of devices on it instead!

He went with 48V, since it’s a voltage that’s high enough to be efficient, easy to get equipment like DC-DCs for, safe when it comes to legal matters concerned, and overall compatible with his solar panel setup. Since then, he’s been putting devices like laptops, chargers and lamps onto the DC rail instead of having them be plugged in, and his home infrastructure, which includes a rack full of Raspberry Pi boards, has been quite content running 24/7 from the 48V rail. There’s a backup PSU from regular AC in case of overcast weather, and in case of grid power failures, two hefty LiFePO4 accumulators will run all the 48V-connected appliances for up to two and a half days.

The setup has produced and consumed 115kWh within the first two months – a hefty contribution to a hacker’s energy independence project, and there’s enough specifics in the blog post for all your inspiration needs. This project is a reminder that low-voltage DC network projects are a decent choice on a local scale – we’ve seen quite viable proof-of-concept projects done at hackercamps, but you can just build a small DC UPS if you’re only looking to dip your feet in. Perhaps, soon we’ll figure out a wall socket for such networks, too.

Keeping An Eye On Heating Oil

Energy costs around the world are going up, whether it’s electricity, natural gas, or gasoline. This is leading to a lot of people looking for ways to decrease their energy use, especially heading into winter in the Northern Hemisphere. As the saying goes, you can’t manage what you can’t measure, so [Steve] has built this system around monitoring the fuel oil level for his home’s furnace.

Fuel oil is an antiquated way of heating, but it’s fairly common in certain parts of the world and involves a large storage tank typically in a home’s basement. Since the technology is so dated, it’s not straightforward to interact with these systems using anything modern. This fuel tank has a level gauge showing its current percentage full. A Raspberry Pi is set up nearby with a small camera module which monitors the gauge, and it runs OpenCV to determine the current fuel level and report its findings.

Since most fuel tanks are hidden in inconvenient locations, it makes checking in on the fuel level a breeze and helps avoid running out of fuel during cold snaps. [Steve] designed this project to be reproducible even if your fuel tank is different than his. You have other options beyond OpenCV as well; this fuel tank uses ultrasonic sensors to measure the fuel depth directly.

A wooden table with a puzzle on top of it sits in an off white room with a light wood floor. A red chair sits behind the table and the slats of the rolled away tambour top are visible.

Tambour Table With A Puzzling Secret

Some people really like puzzles. [Simone Giertz] is one of these serious puzzle lovers and built a transforming table (YouTube) to let her easily switch between puzzles and more mundane tasks, like eating.

While there are commercial solutions out there for game tables with removable tops and simpler solutions like hinged lids, [Giertz] decided to “make it more complicated and over-engineered than that.” A tambour top that rolls out of the way makes this a unique piece of furniture already, but the second, puzzle table top that can be raised flush with the sides of the table really brings this to the next level.

If that wasn’t already enough, the brass handles on the table are also custom made. In grand maker tradition, [Giertz] listened to her inner MYOG (Make Your Own Gnome) and got a lathe to learn to make her own handles instead of just buying some off the shelf.

If you’re less enamored of puzzles, you may want to see how Jigsaw Puzzles are Defeated. If you’re worried about losing pieces, check out these 3D Printed Sliding Puzzles.

Continue reading “Tambour Table With A Puzzling Secret”