Groucho Marx famously said, “Time flies like an arrow, but fruit flies like a banana.” As insulting as it is, researchers often use fruit flies for research because they have similar behavior and genetics to humans. For example, the flies exhibit signs of anxiety, stress, and many common diseases. Researchers at Imperial College London built an inexpensive and customizable research platform for fruit flies — the ethoscope — that uses a 3D printed enclosure and a Raspberry Pi to study our winged counterparts. You can see a video about the ethoscope, below.
By using a camera, the Pi can watch the flies, something researchers used to do by hand. The software is easy to customize. For example, while studying sleep deprivation, the ethoscope could detect when a fly didn’t move for 20 seconds and rotate its tube to wake it up.
Fire safety is drilled into us from a young age. And for good reason, too, because fire hazards are everywhere in the average home. Even a small fire can turn devastatingly dangerous in a matter of minutes. But how do you get kids to really pay attention to scary (and often boring) adult concepts? You can teach a kid to stop, drop, and roll until you’re blue in the face and still might not drive home the importance of fire prevention. Subjects like this call for child-sized visual aids that ignite imaginations.
That’s exactly what firefighters in Poznań, Poland did in collaboration with mlabs, a local software company. They built a mobile, interactive fire safety education tool that simulates common household fire hazards in great detail (translated). This is easily the most tricked-out dollhouse we’ve ever seen. The many different hazard scenarios are controlled via touchscreen using a custom-built application. At the tap of a button, the house becomes a total death trap. The lamp-lit hazards glow realistically and with varied intensity, and there is actual smoke coming out of them that triggers smoke detectors. Cameras embedded throughout the house provide a first-person view of the terror on a nearby monitor.
Almost no room is safe for the figurine family that lives inside this intricately detailed 1:12 scale dwelling. Dad’s in the kitchen standing idly by while food scorches on the stove. Grandma’s sitting on her bed upstairs, her forgotten cigarette burning a hole in the duvet. Daughter is overloading the electrical outlets in her bedroom with all her gizmos. Smoldering coals have spilled out from the toppled stove in the utility room.
This isn’t the first smart dollhouse we’ve seen, but it’s probably the most intriguing. The fire safety dollhouse was on display this week at POL-EKO-SYSTEM, an annual environmental fair in Poznań. Nowhere near Poland? Check out the video after the break.
Plywood laser-cuts fairly well but has drawbacks when used in serious production runs, as [Marie] explains in a blog post about a quest for the ultimate laser-cutting plywood. One of the things [Nervous System] makes and sells is generative jigsaw puzzles, and they shared their experience with the challenges in producing them. The biggest issue was the wood itself. They ended up getting a custom plywood made to fit their exact needs, a process that turned out neither as complex nor as unusual as it may sound.
An example of how a dense knot hidden in one of the plywood layers caused the laser to not cut all the way through.
Plywood is great because it’s readily available, but there are some drawbacks that cause problems when trying to do serious production of laser-cut plywood pieces. Laser cutting works best when the material being cut is consistent, but there can be areas of inconsistent density in plywood. If the laser encounters an unexpected knot somewhere in the wood, there is no way to slow down or to increase power to compensate. The result is a small area where the laser perhaps doesn’t quite make it through. A picture of an example from my workshop shows what this looks like.
When doing basic project work or prototyping, this kind of issue is inconvenient but usually some trimming and sanding will sort things out. When doing a production run for puzzles like [Nervous System] was doing, the issue is more serious:
A jigsaw puzzle with a large number of cuts in a relatively small area has a higher chance of running into any problem spots in the material. If they exist, the laser will probably encounter them.
Trouble spots in plywood can be on the inside layers, meaning they can’t be detected visually and are only discovered after they cause an incomplete cut.
Increasing laser power for the whole job is an incomplete solution, as excessive laser power tends to make the cuts uglier due to increased scorching and charring.
An inspection process becomes needed to check each puzzle piece for problems, which adds time and effort.
A puzzle that had even one piece that did not cut properly will probably be scrapped because rework is not practical. That material (and any time and money that went into getting the nice artwork onto it) becomes waste.
Plywood is great stuff and can look gorgeous, but [Marie] says they struggled with its issues for a long time and eventually realized they had gone as far as they could with off-the-shelf plywoods, even specialty ones. They knew exactly what they needed, and it was time for something custom-made to serve those specific needs.
Having your own plywood custom-made may sound a little extreme, but [Marie] assures us it’s not particularly difficult or unreasonable. They contacted a small manufacturer who specialized in custom aircraft plywoods and was able to provide their laser-cut plywood holy grail: a 3-ply sheet, with high quality basswood core with birch veneers, and a melamine-based glue. It cuts better than anything else they have used, and [Marie] says that after four years they had certainly tried just about everything.
Not every project is meant to solve a new problem. Some projects can be an extension of an existing solution just to flex the geek muscles. One such project by [limbo] is the Web Clock 2.0 which is an internet-connected clock.
Yes, it uses a WEMOS D1 mini which is equipped with an ESP-12F (ESP8266) and yes, it uses an LCD with an I2C module to interface the two. The system works by connecting to the Google servers to get GMT and then offsets it to calculate the local time. It also has the hourly nagging chime to let you know that another precious hour of your life has gone and you need to set it up.
What [limbo] adds to the conventional functionality is a LAN application to send custom messages to the LCD. The software is called ‘Clock Commander’ and can be downloaded as a Windows binary through the source code is unavailable for now. Simply point it to the correct IP address and you can then send it commands to display stuff as well as control the sound. The project comes with Lua scripts and instruction how to DIY.
We imagine this can be used to create a custom geeky table clock or hack a digital coo-coo clock to drive your co-workers crazy at the press of a button. For those who are looking for something with lasers, check out the Laser Pointer Clock for a slightly more challenging build. Continue reading “The Web Clock You Can Control Over A LAN”→
Making PCBs with the toner transfer method has been around since you could buy your traces at Radio Shack. There are a million techniques for removing copper from sheets of fiberglass, from milling to using resist pens, to the ubiquitous laser printer toner transfer. Here’s a technique we haven’t seen before. [Darko Volk] is calling this ‘chemotransfer’. It’s mostly a laser printer toner transfer process, but the toner is transferred from paper to copper with the help of a special mix of solvents.
This chemotransfer process is almost identical to the usual process of making a toner transfer PCB. First, the design is printed in reverse on dextrin-coated paper, the paper is placed down on polished copper, the entire assembly is sent through a laminator, and finally the board is etched with the chemical of your choice. The key difference here is a solvent applied to the copper just before the design is laid down. [Darko Volk] made a mixture of 25% “cleaning petrol” (benzene, naphtha, or gasoline, or some sort of light hydrocarbon, apparently), 5% linseed oil, and 70% isopropanol. This apparently aids in releasing the toner from the paper and sticking it down to the copper.
From there, the process is effectively a standard toner transfer process. [Darko Volk] is using a solution of sodium persulphate for the etch, and rigged a camera up to a CNC machine for the drilling.
This process can be expanded to two-layer boards very easily using a light table to align the layers of paper before placing them down on the copper. You can check out a video of the fabrication of a single side and double sided board below.
Having a child is perhaps the greatest “hack” a human can perform. There’s no soldering iron, no Arduino (we hope), but in the end, you’ve managed to help create the most complex piece of machinery in the known galaxy. The joys of having a child are of course not lost on the geekier of our citizens, for they wonder the same things that all new parents do: how do we make sure the baby is comfortable, how many IR LEDs do we need to see her in the dark, and of course the age old question, should we do this with a web app or go native?
If you’re the kind of person who was frustrated to see that “What to Expect When You’re Expecting” didn’t even bother to mention streaming video codecs, then you’ll love FruitNanny, the wonderfully over-engineered baby monitor created by [Dmitry Ivanov]. The product of nearly two years of development, FruitNanny started as little more than a Raspberry Pi 1n a plastic lunch box. But as [Dmitry] details in his extensive write-up, the latest iteration could easily go head-to-head with products on the commercial market.
[Dmitry] gives a full bill of materials on his page, but all the usual suspects are here. A Raspberry Pi 3 paired with the official NoIR camera make up the heart of the system, and the extremely popular DHT22 handles the environmental monitoring. A very nice 3D printed case, a lens intended for the iPhone, and a dozen IR LEDs round out the build.
The software side is where the project really kicks into high gear. Reading through the setup instructions [Dmitry] has provided is basically a crash course in platform-agnostic video streaming. Even if a little bundle of joy isn’t on your development roadmap, there’s probably a tip or two you can pick up for your next project that requires remote monitoring.
[Niklas Roy] built a windmill-powered music box for his backyard, and it was so awesome all the neighbors wanted to take a picture of it. Someone even liked it so much that he stole [Niklas]’s windmill in the middle of the night. (We kind of don’t blame them, it’s a gorgeously clean build.)
In the past few weeks [Niklas] has been mass-producing 20 windmills for the KIKK Festival 2017 to be held in November in Namur, Belgium. The windmills will operate in a cluster, and all play “Für Elise” when the wind blows. However, each one is driven independently and so the music is asynchronous. Since he was building a bunch anyway, he built a replacement windmill for his backyard, and documented how to do it.
What [limbo] adds to the conventional functionality is a LAN application to send custom messages to the LCD. The software is called ‘Clock Commander’ and can be downloaded as a Windows binary through the source code is unavailable for now. Simply point it to the correct IP address and you can then send it commands to display stuff as well as control the sound. The project comes with Lua scripts and instruction how to DIY.
