Snail Is Actually Cleverly Strange Geocaching Waypoint

November 11, 2017 by 12 Comments

Basic geocaching consists of following GPS coordinates to a location, then finding a container which is concealed somewhere nearby. Like any activity, people tend to add their own twists to keep things interesting. [Jangeox] recently posted a video of the OLED Snail 2.0 to show off his most recent work. (This is a refinement of an earlier version, which he describes in a blog post.)

Another of [Jangeox]’s Electronic Waypoints
[Jangeox] spices up geocaching by creating electronic waypoints, and the OLED Snail is one of these. Instead of GPS coordinates sending someone directly to a goal, a person instead finds a waypoint that reveals another set of coordinates and these waypoints are followed like a trail of breadcrumbs.

A typical waypoint is an ATTINY85 microcontroller programmed to display an animated message on the OLED, and the message reveals the coordinates to the next waypoint. The waypoint is always cleverly hidden, and in the case of the OLED Snail 2.0 the enclosure is the shell of a large snail containing the electronics encased in resin. This means that the devices have a finite lifespan — the battery sealed inside is all the power the device gets. Fortunately, with the help of a tilt switch the electronics can remain dormant until someone picks it up to start the show. Other waypoints have included a fake plant, and the fake bolt shown here. Video of the OLED Snail 2.0 is embedded below.

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Fluid Simulations In The Kitchen Sink

November 11, 2017 by 19 Comments

In an age of ultra-powerful GPUs and cheap processors, computational techniques which were once only available to those with a government-sized R&D budgets are now available to the everyday hacker. An example of industry buzzword turned desktop software is the field of “computational fluid dynamics”, which put simply allow modeling how gasses or liquids will behave when moving through a cavity under specific conditions. Extensive utilization of these fluid simulations are often cited as one of breakthrough techniques which allowed SpaceX to develop their engine technology so rapidly when compared to Apollo and Shuttle era methods.

But just because anyone with a decent computer has access to the technology used for developing rocket engines doesn’t mean they have to use it. What if you prefer to do things the old-fashioned way? Or what if, let’s me honest, you just can’t figure out how to use software like Autodesk CFD and OpenFOAM? That’s exactly where [Desi Quintans] found himself when developing GUST, his cooling duct for i3-type 3D printers.

[Desi] tried to get the big name fluid simulation projects working with his prototype designs for an improved cooling duct, but had no end of trouble. Either the learning curve was too steep, or the simulation wasn’t accurate enough to give him any useful data. But remembering that air is itself a fluid, [Desi] took his simulation from the computer to the sink in order to better visualize what his cooling duct was doing to the airflow.

[Desi] printed up a box with a hole in the bottom that would connect up to his nozzles under test. As the volume of water in the box would be a constant between tests, he reasoned that this would allow him to evaluate the different nozzles at the same pressure. Sure enough, he found that the original nozzle design he was using caused chaotic water flow, which backed up what he was seeing in his experiments when mounted onto the printer.

After several iterations he was able to tame the flow of water by using internal baffles and fins, which when tested in water created something of a laminar flow effect. When he tried this version on the printer, he saw a clear improvement in part cooling, verifying that the behavior of the air and water was close enough for his purposes.

We’ve seen other projects that successfully used fluid simulations in their design before, but the quick and dirty test procedure [Desi] came up with certainly has its charms.

DIY Injection Mold Design For The Home Shop

November 11, 2017 by 30 Comments

3D printing is great for prototyping, and not bad for limited runs of parts. Unfortunately though it really doesn’t scale well beyond a few pieces, so when you’re ready for the mass market you will need to think about injection molding your parts. But something like that has to be farmed out, right? Maybe not, if you know a thing or two about designing your own injection molds.

The video below comes from [Dave Hakkens] by way of his Precious Plastic project, whose mission it is to put the means of plastic recycling into the hands of individuals, rather than relying on municipal programs.  We’ve covered their work before, and it looks like they’ve come quite a way to realizing that dream. This tutorial by [Dave]’s colleague [Jerry] covers the basic elements of injection mold design, starting with 3D modeling in Solidworks. [Jerry] points out the limitations of a DIY injection molding effort, including how the thickness of parts relates to injection pressure. Also important are features like gentle curves to reduce machining effort, leaving proper draft angles on sprues, and designing the part to ease release from the mold. [Jerry] and [Dave] farmed out the machining of this mold, but there’s no reason a fairly complex mold couldn’t be produced by the home gamer.

When you’re done learning about mold design, you’ll be itching to build your own injection mold machine. Precious Plastic’s tutorial looks dead simple, but this machine looks a little more capable. And why CNC your molds when you can just 3D print them?

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A Sandbox For DIY Pinball Design

November 11, 2017 by 21 Comments

If you’ve always wanted to build your own pinball machine but have no idea where to start, this is the project for you. [Chris] is in the process of building a 3/4 size pinball table and is currently in the waiting-for-parts stage. As they arrive, he is testing them in a sandbox he built in an afternoon. Let [Chris]’s proving ground be your quick-start guide to all the ways you could approach the two most important parts of any pin: the flippers and targets.

The field of play is a sturdy piece of particle board, and the cardboard walls are attached with hot glue. [Chris] designed and printed a pair of flippers that are driven by some cheap remote door lock motors he found at a popular online auction house. You can see how snappy are in the test video after the break.

We love the crisp action and elegant simplicity of the spring-loaded drop targets [Chris] designed. Right now he resets them manually, but soon they will be reset by a solenoid or maybe a motor. We can’t wait to see how the table turns out. In the meantime, we’ll have to go back to drooling over this amazing life-size 3D-printed pinball machine.

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Automating A Bowl Feeder With Arduino

November 11, 2017 by 5 Comments

Search for “bowl feeder” on Hackaday and you’ll get nothing but automated cat and dog feeders. That’s a shame, because as cool as keeping your pets fed is, vibratory bowl feeders are cooler. If you’ve seen even a few episodes of “How It’s Made” you’re likely to have seen these amazing yet simple devices, used to feed and align small parts for automated assembly. They’re mesmerizing to watch, and if you’ve ever wondered how parts like the tiny pins on a header strip are handled, it’s likely a bowl feeder.

[John] at NYC CNC is building a bowl-feeder with Arduino control, and the video below takes us on a tour of the build. Fair warning that the video is heavy on the CNC aspects of milling the collating outfeed ramp, which is to be expected from [John]’s channel. We find CNC fascinating, but if you’re not so inclined, skip ahead to the last three minutes where [John] discusses control. His outfeed ramp has a slot for an optical sensor to count parts. For safety, the Arduino controls the high-draw bowl feeder through an external relay and stops the parts when the required number have been dispensed.

We know, watching someone use a $20,000 CNC milling station might seem overkill for something that could have been 3D printed, but [John] runs a job shop after all and usually takes on big industrial jobs. Or small ones, like these neat color-infill machine badges.

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A Motion Sensing Light For Your Entrance Hallway

November 11, 2017 by 25 Comments

Arriving home to a dark house with an armful of anything is usually an exercise in fumbling confusion until someone manages to turn on a light. [Pavel Gesyuk] has circumvented this problem entirely by building and installing a motion detecting entrance light!

[Gesyuk] is using an Arduino clone by the name of  Funduino Mini Pro, a 2-channel, 2-way relay, — he only needed one, but you use what you have on hand — a recycled power supply to convert 220V AC to 5V DC, and an infrared sensor.

The project’s goal — in excess of a lighting solution for an entrance hallway — was the learn the ins and outs of the Arduino and motion sensors. After some initial hurdles familiarizing himself with the Arduino, [Gesyuk] wired everything together on a protoboard and stuck it in a plastic case — loose wires in a high traffic area doesn’t a safe home make.

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(Nearly) All Your Computers Run MINIX

November 11, 2017 by 68 Comments

Are you reading this on a machine running a GNU/Linux distribution? A Windows machine? Or perhaps an Apple OS? It doesn’t really matter, because your computer is probably running MINIX anyway.

There once was a time when microprocessors were relatively straightforward devices, capable of being understood more or less in their entirety by a single engineer without especially God-like skills. They had buses upon which hung peripherals, and for code to run on them, one of those peripherals had better supply it.

A modern high-end processor is a complex multicore marvel of technological achievement, so labyrinthine in fact that unlike those simple devices of old it may need to contain a dedicated extra core whose only job is to manage the rest of the onboard functions. Intel processors have had one for years, it’s called the Management Engine, or ME, and it has its own firmware baked into the chip. It is this firmware, that according to a discovery by [Ronald Minnich], contains a copy of the MINIX operating system.

If you are not the oldest of readers, it’s possible that you may not have heard of MINIX. Or if you have, it might be in connection with the gestation of [Linus Torvalds]’ first Linux kernel. It’s a UNIX-like operating system created in the 1980s as a teaching aid, and for a time it held a significant attraction as the closest you could get to real UNIX on some of the affordable 16-bit desktop and home computers. Amiga owners paid for copies of it on floppy disks, it was even something of an object of desire. It’s still in active development, but it’s fair to say its attraction lies in its simplicity rather than its sophistication.

It’s thus a worry to find it on the Intel ME, because in that position it lies at the most privileged level of access to your computer’s hardware. Your desktop operating system, by contrast, sees the hardware through several layers of abstraction in the name of security, so a simple OS with full networking and full hardware access represents a significant opportunity to anyone with an eye to compromising it. Placing tinfoil hats firmly on your heads as the unmistakable thwop of black helicopters eases into the soundscape you might claim that this is exactly what they want anyway. We would hope that if they wanted to compromise our PCs with a backdoor they’d do it in such a way as to make it a little less easy for The Other Lot. We suspect it’s far more likely that this is a case of the firmware being considered to be an out-of-sight piece of the hardware that nobody would concern themselves with, rather than a potential attack vector that everyone should. It would be nice to think that we’ll see some abrupt updates, but we suspect that won’t happen.

Intel I7 processor underside: smial [FAL].