Born with just one foot, [Nerraw99] had to work around prosthetics all his life. Finally getting fed up with the various shortcomings of his leather and foam foot, he designed, tweaked, printed and tested his own replacement!
After using Structure Sensor to scan both his feet, [Nerraw99] began tooling around with the model in Blender and 3D printing them at his local fablab/makerspace: MakerLabs. It ended up taking nearly a dozen printed iterations — multiple printing issues notwithstanding — to get the size right and the fit comfortable. Not all of the attempts were useless; one version turned out to be a suitable water shoe for days at the beach!
How do you get the attention of thousands of Hackaday readers? Build a clock! There are just so many choices to agonize over. Do you go with a crystal as a clock source, a fancy oven controlled crystal oscillator, or just mains voltage? Should you even think about putting a GPS module in a clock? All these are very interesting questions that encourage discussion or learning, and that’s what Hackaday is all about. Clocks are cool, and the engineering behind them is even cooler.
For one of [Nick]’s Hackaday Prize entries, he’s building a minimalist GPS clock. First up, the centerpiece of every clock, the display. There are eight seven-segment displays, two each for the hours, minutes, and seconds, and a smaller digit for tenths of a second. These displays are controlled by an ATXmega32E5, an upgrade on an earlier version of this project that only used an ATtiny and a MAX6951 LED driver.
The GPS wizardry is where this project gets really cool. [Nick] is using a SkyTraq Venus838LPx-T (that’s also available on a breakout board on Tindie). This GPS chip has a handy edge mount SMA connector to receive the signals from a GPS satellite, and has a bidirectional UART to dump the NMEA time codes and a PPS output. By combining the timecode, PPS output, and playing around with the timers on the microcontroller, [Nick] has a fantastically accurate clock that also looks great.
Can you really catch lightning with Mjolnir, the mythical hammer of Thor? If you’re [James Hobson] you can get pretty darn close. He’s a long time writer at Hackaday who’s been building an epic following on his YouTube channel by making the digital effects of blockbuster movies into practical effects. Today he released a video showing how he channeled a jolt of lightning with hammer held high.
The lightning source for this hack is a huge Tesla coil held overhead by a telescoping lift. Humans and high voltage mix poorly, which is why you can’t actually tell this is [James]. He’s wearing a full body suit of grounded chainmail which serves as a Faraday cage, safely directing the current around him to avoid a literally heart-stopping moment. Check out the antics in the video after the break.
Longtime readers will remember [Caleb Kraft’s] take on Mjolnir, a build that placed the Tesla coil in the hammer itself. [James]’ version is undeniably more impressive, with the tradeoff that it’s wholly unportable. While we’re on the topic of mythical hammers, our other most favorite build is the delightful prank build which makes the hammer unliftable except by the recognized owner.
There’s a trick in the world of plastic enclosures. The threaded insert is a small cylinder of metal with threads on the inside and a rough edge on the outside. To make a plastic part with a hole for securely connecting bolts that can be repeatedly screwed without destroying the plastic, you take the threaded insert and press it (usually with the help of a soldering iron to heat the insert) into a hole that’s slightly smaller than the insert. The heat melts the plastic a little bit and allows for the insert to go inside. Then when it cools the insert is snugly inside the plastic, and you can attach circuit boards or other plastic parts using a bolt without stripping the screw or the insert. We’ve seen Hackaday’s [Joshua Vasquez] installing threaded inserts with an iron, as well as in a few other projects.
This trick is neat. And I’ve now proven that it does not work with neodymium magnets.
Sometimes great projects keep evolving. [Bithead942] built himself an R2-D2 to accompany him when he goes a-trooping — but something didn’t feel quite right. Turns out, R2 was missing its signature beeping banter, so he made it more contextually responsive by implementing a few voice commands.
[Bithead942]’s main costume is that of an X-Wing pilot, and the replica helmet works perfectly; it already has a fake microphone — easily replaced with a working model — and the perfect niche to stash the electronics in the ‘mohawk.’
Even though the helmet has the perfect hiding spot for a circuit, space is still at a premium. Services like Alexa tend to be pretty accurate, but require WiFi access — not a guarantee on the convention floor. Instead, [bithead942] found that the EasyVR Shield 3.0 voice recognition board provided a suitable stand-in. It needs a bit of training to work properly(cue the montage!), but in the end it compares fresh audio commands to the ‘training’ files it has stored, and if there’s a match, triggers a corresponding serial port. It’s not perfect, but it most certainly works!
A few weeks ago I needed a power strip in my home office. The outlet in question is located behind a filing cabinet so it would need a low profile plug. I jumped on Amazon to buy a surge suppressor strip. That’s when I noticed strips with rotating plugs. I’ve always had some apprehensions about plugs like that, though I could never quite put my finger on why. Looking at the reviews on this particular plug, I found some scary issues. Photos of melted plugs, melted outlets, and cries of “fire hazard”. So I did what any crazy hacker would do – bought two power strips. One with a fixed right angle plug to use in my office, and one with a rotating plug to tear down.
Failed plug – from Amazon reviews
Surge suppressors, power strips, outlet strips, they have many names. Underwriter’s Laboratories (UL) calls them “Relocatable power taps”. They all have several outlets, most have a circuit breaker of some sort inside, and some have circuits for surge suppression. These are some of the most common devices to find in the modern home. Many of our houses were designed and built before surround sound, cable boxes, computers, modems, cell phone chargers, tablet chargers, and all our other modern conveniences. There weren’t as many electrical loads, so the houses didn’t have many outlets. Power strips solve this problem.
After a couple of days, I had my strips in hand. I expected the plug to rotate once – maybe 270 degrees. That would indicate there were wires connecting the rotating head to rest of the plug. Not so – this plug would spin round and round all day long.
[Taciuc Marius] and his colleague noticed that days with low atmospheric pressure plus caffeine in their system meant a spike in blood pressure. Considering how this might impact his cardiovascular health, he decided to make a relative pressure barometer out of a jar to help him decide whether he should really have another cup of coffee.
Aside from a 3D printer, you’ll need to assemble a small jar with a lid, some screws, lock washers, nuts, and a flexible membrane — a piece of a rubber glove or balloon will do nicely. [Marius] details the build process on his project page, advising others to print the parts at 0.2 resolution — potentially even upping the extrusion multiplier to 1.1 — to prevent gaps in the print that would compromise the airtight seal needed for the barometer to work properly.
Additionally, thick glue or epoxy is recommended for the rest of the assembly process — it doesn’t have to be pretty, but it does need to be sealed! The final product can be easily tested by simply holding the jar.
While this barometer helps one make healthy choices, not all are created equal. This one tells you flat out how you should consider getting to work, while others have been tricked into behaving like touch sensors.
