Tiny ESP32 Strider Walks The Walk

Wheels might be the simplest method of locomotion for robots, but walkers are infinitely more satisfying to watch. This is certainly the case for [Chen Liang’s] tiny Strider walker controlled by a ESP32 camera board.

The Strider mechanism might look similar to Strandbeest walkers, but it lifts its feet higher, allowing it to traverse rougher terrain. [Chen]’s little 3D printed version is driven by a pair of geared N20 motors, with three legs on each side. The ESP32 camera board allows for control and an FPV video feed using WiFi, with power coming from a 14500 LiFePO4 battery. The width required by the motors, leg mechanisms, and bearings means the robot is quite wide, to the point that it could get stuck on something that’s outside the camera’s field of view. [Chen] is working to make it narrower by using continuous rotation servos and a wire drive shaft.

We’ve seen no shortage or riffs on the many-legged walkers, like the TrotBot and Strider mechanism developed by [Wade] and [Ben Vagle], and their website is an excellent resource for prospective builders.

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Small Scale Mad Max: Danny Huynh’s Dystopian Animatronics

The hacker spirit is always alive and well in post-apocalyptic fiction, as characters throw together contraptions from whatever junk they can find. While these might not always be practical or possible in reality, their primary purpose is usually to look the part. This is definitely the case for [Danny Huynh]’s post-apocalyptic animatronic creations, which look like they can slot straight into Mad Max or Fallout.

[Danny] is an avid RC enthusiast, so many of the models are highly customized off-the-shelf RC cars. However, it’s the lifelike moving characters in these models that really catch the eye. Their hands and feet move with the steering and throttle, and in the motorcycle builds they will often lean with the turns. Other notable builds include a hexapedal taxi and a couple of animatronic bands.

All the vehicle builds are electric, but it looks like [Danny] often includes an audio module to simulate a roaring engine. He makes extensive use of servos and linkages for character movement, with wiring and electronics carefully hidden by paint or bodywork.

With all the CGI technology available today, great animatronic builds like an eerily lifelike heart, or a talking Nikola Tesla are all the more impressive to see.

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Lightning Detector Keeps A Tally

Lightning is one of the great forces of nature. The huge releases of electricity release detectable electromagnetic emissions, as you might expect. The team at the [LVL1 Hackerspace] put together a lightning detector of their own; one which keeps count of the number of discharges in the atmosphere.

The device consists of a typical tank circuit tuned to 300kHz, paired with a small telescopic antenna. Lightning strikes in the area induce an oscillation in the circuit which is amplified and then detected by an Arduino. The Arduino measures the voltage of the pulse, which is proportional to the magnitude of the signal detected. A ring of Neopixel LEDs are then switched on relative to the intensity of the signal. Additionally, when not actively detecting strikes, the Arduino instead uses the LEDs to display the current time and a binary count of the number of strikes detected since it has been running.

It’s a simple build, and one that would serve as a great introduction into the world of addressable LEDs and environmental monitoring. If you’d like to go about it another way, you can detect lightning with an SDR, too!

How To Get Good With Wood

It’s perhaps unsurprising that we don’t see much in the way of woodworking here at Hackaday; after all, this is a plastics and metal community if there ever was one. But that doesn’t mean you’ll never come across a situation where a dead tree needs to be cut or shaped to your will, so we appreciate [Eric Strebel] demonstrating some tips and best practices for working with this exceptionally versatile building material.

The first video assumes you’re a lumber neophyte, and goes over topics such as the different species of wood you’re likely to find at the hobby shop, proper sanding technique, and the differences between cutting with and against the grain. Some of the different cutting tools you can use are also covered, ranging from the humble hobby knife to the band saw. As always, [Eric] sprinkles the video with tips and tricks gained from his considerable professional experience, such as using some glue and a bit of sawdust to fill in any gaps left behind by an uneven joint.

In the second video, things start getting more advanced. [Eric] demonstrates how you can create custom laminates, and how wood can be permanently bent into arbitrary shapes with sufficient steam and clamping pressure. By combining these new techniques with the basic concepts covered in the first video, surprisingly complex shapes can be formed with minimal effort.

[Eric] previously put together a similar series of videos on working with acrylic, a material that’s arguably far more familiar to the Hackaday readership. But whatever material you use, the takeaway message from this series is clear: get the right tools, learn the techniques, and professional results are well within your reach.

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Injection Molding Silicone Parts For Under $50

You’ve likely seen many tutorials on making silicone parts using 3D printed molds online. The vast majority of these methods use a simple pour method to fill the mold. This relies on careful degassing and gentle pouring to reduce the presence of bubbles in the final result. [Jan Mrázek] has been working on an alternative method however, that allows for injection molding at low cost in the home shop.

The process relies on the use of printed resin molds. [Jan] notes that this generally necessitates the use of condensation-cure silicones, as additive types don’t cure well in resin molds. The condensation silicone is mixed up, degassed, and poured into a standard cartridge. From there, it’s installed in a silicone delivery air gun, which uses compressed air to force the silicone out of the nozzle and into the waiting mold.

It’s basically using a bunch of home DIY gear to create a cheap injection molding solution for silicone parts. [Jan] notes that there are a few mods needed to mold design to suit the process, and that 400-800 kPa is a good pressure to inject the silicone at.

Having the silicone injected under pressure is great for complex mold designs, as it forces the material into all the little difficult nooks and crannies. Of course, we’ve seen other methods for making silicone parts before, too. Be sure to sound off in the comments with your own favored techniques for producing quality silicone parts. Video after the break.

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Word clock in the style of the Christmas lights from Stranger Things. If you know, you know.

Stranger Things Message Board Passes The Time By Spelling It Out

Will Netflix’s nostalgic hit Stranger Things be back for a fourth series anytime soon? We could pull out a Ouija board and ask the spirits, but we’d much rather ask closer to the source, i.e. a spirit in the upside down. And you know that the best way to do that is with LEDs — one for each letter of the alphabet so the spirit can spell out their messages.

Arduino, ESP01, and real-time clock powering this Stranger Things word clockAlthough contact with the Demogorgon’s world isn’t likely with [danjovic]’s open-source Stranger Things board, you are guaranteed to get the time spelled out for you every minute, as in, ‘it’s twenty-five (or six) to four’. And if you want to freak out your unwitting friends, you can covertly send messages to it from your phone.

There are two versions now — the original desktop version, and one that hangs on the wall and uses a high-quality photo print for the background. Both use an ESP-01 and an Arduino to help drive the 26 RGB LEDs, and use a DS2321 real-time clock for timing. We love the enameled wiring job on the wall-mount version, but the coolest part has to be dual language support for English and Brazilian Portuguese. You can check out demos of both after the break.

We’ve seen many a word clock around here, but this is probably one of the few that’s dripping with pop culture. If it’s stunning modernism you want, take a look at this painstakingly-constructed beauty.

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Hackaday Links: September 5, 2021

Good news from Jezero crater as the Mars rover Perseverance manages to accomplish for the first time what it was sent to do: collect and cache core samples from rocks. Space buffs will no doubt recall that Perseverance’s first attempt at core sampling didn’t go as planned — the rock that planetary scientists selected ended up being too soft, and the percussive coring bit just turned the core sample into powder. The latest attempt went exactly as planned: the cylindrical coring bit made a perfect cut, the core slipped into the sample tube nested inside the coring bit, and the core broke off cleanly inside the sample tube when it was cammed off-axis. Operators were able to provide visible proof that the core sample was retained this time using the Mastcam-Z instrument, which clearly shows the core in the sample tube. What’s neat is that they then performed a “percuss to ingest” maneuver, where the coring bit and sample tube are vibrated briefly, so that the core sample and any dust grains left around the sealing rim slide down into the sample tube. The next step is to transfer the sample tube to the belly of the rover where it’ll be hermetically sealed after some basic analysis.

Did any Android users perhaps oversleep this week? If you did, you’re not alone — lots of users of the Google Clock app reported that their preset alarms didn’t go off. Whether it was an actual issue caused by an update or some kind of glitch is unclear, but it clearly didn’t affect everyone; my phone mercilessly reminded me when 6:00 AM came around every day last week. But it apparently tripped up some users, to the point where one reported losing his job because of being late for work. Not to be judgmental, but it seems to me that if your job is so sensitive to you being late, it might make sense to have a backup alarm clock of some sort. We all seem to be a little too trusting that our phones are going to “just work,” and when they don’t, we’re surprised and appalled.

There seem to be two kinds of people in the world — those who hate roller coasters, and those who love them. I’m firmly in the latter camp, and will gladly give any coaster, no matter how extreme, a try. There have been a few that I later regretted, of course, but by and large, the feeling of being right on the edge of bodily harm is pretty cool. Crossing over the edge, though, is far less enjoyable, as the owners of an extreme coaster in Japan are learning. The Dodon-pa coaster at the Fuji-Q Highland amusement park is capable of hitting 112 miles (180 km) per hour and has racked up a sizable collection of injuries over the last ten months, including cervical and thoracic spine fractures. The ride is currently closed for a safety overhaul; one has to wonder what they’re doing to assess what the problem areas of the ride are. Perhaps they’re sending crash test dummies on endless rides to gather data, a sight we’d like to see.

And finally, you may have thought that phone phreaking was a thing of the past; in a lot of ways, you’d be right. But there’s still a lot to be learned about how POTS networks were put together, and this phone switch identification guide should be a big help to any phone geeks out there. Be ready to roll old school here — nothing but a plain text file that describes how to probe the switch that a phone is connected just by listening to things like dial tones and ring sounds. What’s nice is that it describes why the switches sound the way they do, so you get a lot of juicy technical insights into how switches work.