Fridge Compressor To 2-Stroke Engine: JB Weld For The Win

August 16, 2017 by 28 Comments

We like this one because it has a real Junkyard Wars feel to it: turning a cast-off fridge compressor into a two-stroke internal combustion engine. [Makerj101] is doing this with tooling no more complicated than a hacksaw and a hand drill. And JB Weld — lots and lots of JB Weld.

[Makerj101]’s video series takes us through his entire conversion process. Despite the outward similarity between compressors and engines, there are enough crucial differences to make the conversion challenging. A scheme for controlling intake and exhaust had to be implemented, the crankcase needed to be sealed, and a cylinder head with a spark plug needed to be fabricated. All of these steps would have been trivial in a machine shop with mill and lathe, but [Makerj101] chose the hard way. An old CPU heat sink serves as a cylinder head, copper wire forms a head gasket and spacer to decrease the compression ratio, and the old motor rotor serves as a flywheel. JB Weld is slathered everywhere, and to good effect as the test run in the video below shows.

Think you recognize [Makerj101]? You probably do, since we featured his previous machine shop-less engine build. This guy sure gets his money’s worth out of a tube of JB Weld.

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The Best Stereo Valve Amp In The World

August 16, 2017 by 83 Comments

There are few greater follies in the world of electronics than that of an electronic engineering student who has just discovered the world of hi-fi audio. I was once that electronic engineering student and here follows a tale of one of my follies. One that incidentally taught me a lot about my craft, and I am thankful to say at least did not cost me much money.

Construction more suited to 1962 than 1992.
Construction more suited to 1962 than 1992.

It must have been some time in the winter of 1991/92, and being immersed in student radio and sound-and-light I was party to an intense hi-fi arms race among the similarly afflicted. Some of my friends had rich parents or jobs on the side and could thus afford shiny amplifiers and the like, but I had neither of those and an elderly Mini to support. My only option therefore was to get creative and build my own. And since the ultimate object of audio desire a quarter century ago was a valve (tube) amp, that was what I decided to tackle.

Nowadays, building a valve amp is a surprisingly straightforward process, as there are many online suppliers who will sell you a kit of parts from the other side of the world. Transformer manufacturers produce readily available products for your HT supply and your audio output matching, so to a certain extent your choice of amp is simply a case of picking your preferred circuit and assembling it. Back then however the world of electronics had extricated itself from the world of valves a couple of decades earlier, so getting your hands on the components was something of a challenge. I cut out the power supply by using a scrap Dymar Electronics instrument enclosure which had built-in HT and heater rails ready to go, but the choice of transformers and high-voltage capacitors was something of a challenge.

Pulling the amplifier out of storage in 2017, I’m going in blind. I remember roughly what I did, but the details have been obscured by decades of other concerns. So in an odd meeting with my barely-adult self, it’s time to take a look at what I made. Where did I get it right, and just how badly did I get it wrong?

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Friday Hack Chat: Graphical Programming Languages With Boian Mitov

August 16, 2017 by 34 Comments

There is a long history of Visual or Graphical Programming Languages, and most of them make more sense than the name of Microsoft’s Visual Basic, C#, and Visual Studio IDE. Some people don’t like to code, and for them, graphical programming languages replace semicolons and brackets with easy-to-understand boxes and wires.

This Friday, we’re going to be talking about graphical programming languages with [Boian Mitov]. He’s a software developer, founder of Mitov Software, and the creator of Visuino, a graphical programming language for the embedded domain. Everything from the Arduino to Teensy, ESP8266, ESP32, the chipKIT, and Maple Mini are supported with this IDE. It’s a simple drag-and-drop way of programming microcontrollers that Scratches an itch (see what I did there?) for an easy way to introduce non-programmers to the embedded world and also provides a faster way to build custom applications.

When it comes to graphical programming languages, we can’t find a better Hack Chat guest than [Boian]. He’s the author of the OpenWire dataflow processing technology — another graphical programming language –, the IGDI+ library, VideoLab, SignalLab, AudioLab, PlotLab, InstrumentLab, and author of VCL for Visual C++. He’s a regular contributor to Blaise Pascal Magazine, too.

During this Hack Chat, we’ll be discussing what makes Visual Programming worth it, how and why it works, when it doesn’t and how to develop a graphical programming language. Visuino will be of special interest, And I’m sure someone will work in a, ‘what’s happening with Max/MSP under Ableton’ question. If you have a question for [Boian], here’s a question sheet to guide the discussion.

Here’s How To Take Part:

join-hack-chatOur Hack Chats are live community events on the Hackaday.io Hack Chat group messaging. This Hack Chat will take place at noon Pacific time on Friday, August 11th. Here’s a time and date converter!

Log into Hackaday.io, visit that page, and look for the ‘Join this Project’ Button. Once you’re part of the project, the button will change to ‘Team Messaging’, which takes you directly to the Hack Chat.

You don’t have to wait until Friday; join whenever you want and you can see what the community is talking about.

Making A Coil Gun Without Giant Caps

August 16, 2017 by 26 Comments

Whenever we see a coil gun project on the Internet, it seems to involve a bank of huge capacitors. [miroslavus] took a different approach with his gun–he wanted his project to be built without those monster caps.

It’s powered by quadcopter LiPo batteries, 2x 1400 MaH drone batteries wired up in series and triggering 21SWG copper coils that [miroslavus] created with the help of a custom 3D-printed winding rig he designed. The rigs have ridges to help you lay the coils down neatly, and they also have mounts for photodiodes, ensuring the gun knows when it’s loaded.

When triggered, the Arduino Nano activates a pair of IRF3205 MOSFETS with logic signals stepped up to 20V, shooting lengths of 7mm or 8mm steel rod. The gun isn’t exactly creating plasma discharges with its launches, but it’s a fascinating project nonetheless.

Check out the disposable camera coil gun project and the coil guns for newbies posts we previously ran.

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Eclipse 2017: Was Einstein Right?

August 16, 2017 by 46 Comments

While most people who make the trek to the path of totality for the Great American Eclipse next week will fix their gazes skyward as the heavenly spectacle unfolds, we suspect many will attempt to post a duck-face selfie with the eclipsed sun in the background. But at least one man will be feverishly tending to an experiment.

On a lonely hilltop in Wyoming, Dr. Don Bruns will be attempting to replicate a famous experiment. If he succeeds, not only will he have pulled off something that’s only been done twice before, he’ll provide yet more evidence that Einstein was right.

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Alexa In A Bunny Rabbit

August 16, 2017 by 13 Comments

The Raspberry Pi is the perfect candidate for Google’s AIY where you can talk to a cardboard box with some electronics in it. [BuddyCasino] took on the challenge of squeezing an Alexa Client in an ESP32 and to make things interesting, a bunny rabbit was chosen as the host of the virtual assistant.

A few months ago, we did a teardown of the Google AIY Kit where [BuddyCasino] commented that he managed to port the Echo Dot client into and ESP32. Sure enough, the video below shows a demonstration of the build in action. The project uses the MAX98357A which is the same I2S DAC used in the Google AIY Voice Hat. For the microphone, the device is again an I2S component however unlike the Google AIY kit which uses the SPH0645LM4H, [BuddyCasino] opted for the ICS-43434.

Two NeoPixels are employed as visual indicators for various purposes. This project is an excellent example of how simple and cheap modern-day designs have become. We are hoping to see the author add more features to the design and who knows maybe we will see a Google Assistant port on the ESP32 in the future. Check out the original teardown for more inspiration. Continue reading “Alexa In A Bunny Rabbit” →

You Probably Don’t Want To Find This Toilet In Your Washroom

August 16, 2017 by 12 Comments

Ok, this one is a bit bizarre, but in perfect keeping with the subject matter: a talking toilet ripped from the pages of the Captain Underpants children’s books. Hackaday.io user [hamblin.joe]’s county fair has a toilet decorating contest and at the suggestion of their neighbour’s son, [hamblin.joe] hatched a plan to automate the toilet using an Arduino in the fashion of the hero’s foes.

Two Arduinos make up this toilet’s brains, an Adafruit Wave Shield imbues it with sound capabilities, and a sonic wave sensor will trigger the toilet’s performance routine when someone approaches. A windshield wiper motor actuates the toilet bowl lid via a piece of flat iron bar connected to a punched angle bracket. Installing the motor’s mount was a little tricky, since it had to be precisely cut so it wouldn’t shift while in the toilet bowl. A similar setup opens the toilet tank’s lid, but to get it working properly was slightly more involved. Once that was taken care of there was enough room left over for a pair of 12V batteries and a speaker. Oh, and a pair of spooky eyes and some vicious looking teeth.

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