Spin Me Right Round, Baby: Generator Building Experiments For Mere Mortals

August 13, 2019 by Brian McEvoy 38 Comments

How many of you plan to build a wind-powered generator in the next year? Okay, both of you can put your hands down. Even if you don’t want to wind your coils manually, learning about the principles in an electric generator might spark your interest. There is a lot of math to engineering a commercial model, but if we approach a simple version by looking at the components one at a time, it’s much easier to understand.

For this adventure, [K&J Magnetics] start by dissect a commercial generator. They picked a simple version that might serve a campsite well, so there is no transmission or blade angle apparatus to complicate things. It’s the parts you’d expect, a rotor and a stator, one with permanent magnets and the other with coils of wire.

The fun of this project is copying the components found in the commercial hardware and varying the windings and coil count to see how it affects performance. If you have ever wound magnet wire around a nail to make an electromagnet, you know it is tedious work so check out their 3D printed coil holder with an embedded magnet to trigger a winding count and a socket to fit on a sewing machine bobbin winder. If you are going to make a bunch of coils, this is going to save headaches and wrist tendons.

They use an iterative process to demonstrate the effect of multiple coils on a generator. The first test run uses just three coils but doesn’t generate much power at all, even when spun by an electric drill. Six windings do better, but a dozen finally does the trick, even when turning the generator by hand. We don’t know about their use of cheap silicone diodes though, that seems like unintentional hobbling, but we digress.

Making turbine blades doesn’t have to be a sore chore either, and PVC may be the ticket there, you may also consider the vertical axis wind turbine which is safer at patio level. Now, you folks building generators, remember to tip us off!

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Shop-Made Tools Turn Cheap Steel Into Telescoping Tubes

August 13, 2019 by Dan Maloney 24 Comments

Beginning metalworkers are often surprised at just how cheap steel can be. It’s a commodity made by the gigaton, and there are always plenty of extra pieces and scraps left over from big projects that are available for pennies a pound. But what you’ve got is often not what you need, especially when it’s steel tubing with welded seams that prevents one tube from fitting inside another.

[Jason Marburger] from Fireball Tool has some great tips for cleaning interior welds in steel tubing. The first part of the video below details manual methods for cleaning off seam welds, including chiseling, sanding with a narrow belt sander, and grinding them down with a die grinder. Those all work well, but only for short lengths of tubing. Longer tubes need special treatment, which is where the clever tools [Jason] designed come in handy.

By attaching a chunk of high-speed steel to a slug made from the next size tube down and driving it through the tube to be cleaned with a hefty piece of threaded rod, he basically created ain internal shaper to shave the weld down. It works like a charm, as does the tool he made for round tubing by laying a bead of hard facing welding rod around the edge of a mild steel slug. Driving this tool into the seamed round tubing with a shop press cleaned up the weld nicely too.

Hats off to [Jason] for coming up with a couple of great shop tips to keep in mind. We’ve seen similar expedient tools for metalworking lately, like this homemade die-punching tool and a linear track to keep your plasma cutter in line.

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Giving The Amstrad CPC A Voice And A Drum Kit

August 12, 2019 by Erin Pinheiro 7 Comments

Back in the ’80s, home computers weren’t capable of much in terms of audio or multimedia as a whole. Arguably, it wasn’t until the advent of 16-bit computers such as the Amiga that musicians could make soundtrack-quality music without having to plug actual studio gear up to their machines. [Michael Wessel] is trying to bring some of that and many more features to the Amstrad CPC with his ambitious LambdaSpeak 3 project, an expansion card built completely up from scratch and jam-packed with features.

First, and likely giving it its name, is the speech synthesizer. [Michael] has made an emulation mode where his card can act just like the original SSA-1 expansion, being able to be controlled by the same software as back then. By default, the card offers this mode with an Epson S1V30120 daughterboard (which is based on DECTalk synthesis), however for further authenticity you also have the option of fitting it with an SP0256-AL2 chip, the same one used in the original Amstrad hardware in 1985.

As for the more musical part of the project, the board supports 4-channel PCM playback, much like the Amiga’s sound offering. This can be used for a drum machine sequencer program, and it has an Amdrum mode, emulating another expansion from the original Amstrad days. Sample playback can also be used alongside the speech synthesis as shown here, with random allophone beats that wouldn’t sound out of place in a Kraftwerk recording. Finally, by using the UART interface included on the LambdaSpeak, you can also turn the CPC itself into a synth by giving it MIDI in/out and interfacing a controller in real time with the computer’s AY-3-8912 sound chip.

If you like modern expansions giving old computers new life, did you know that you can get just about any retro computer online, perhaps a TRS-80, an Amiga and even a Psion Organizer? And if you’re interested in just using old systems’ sound chips with modern USB MIDI controllers, it’s easy to make a microcontroller do all the heavy lifting.

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KVM Foot Switch In A Few Steps

August 12, 2019 by Kristina Panos 6 Comments

[Radishmouse], despite the handle, is not a mouse guy. Give him a keyboard and he will get around just fine in any OS or program. As it is, he’s got a handful of ThinkPads, each running a different OS. He wanted to be able to switch his nice mechanical keyboard between two laptops without the hassle of unplugging and replugging the thing. His solution: a DIY KVM foot switch.

He’s been learning about electronics and 3D design, and this problem was the perfect opportunity to dig in and get his hands dirty. After learning enough about the USB protocol and switches to figure out what had to happen, he made a prototype from a pâte tub. Though undeniably classy, this vessel would never survive the rigors of foot-stomping in feline territory. Fortunately, [radishmouse] has also been learning about 3D design. After some trial and error, he came up with a sturdy, curvy 3D-printed two-piece enclosure. We particularly like the blocks built into the bottom piece that shore up the USB ports.

There are lots of reasons to build input controls for those under-utilized appendages at the ends of your legs. You could control your ‘scope with a probe in each hand, or use a foot switch to relocate an inconvenient power button.

Via [r/functionalprint]

EL Wire Makes For A Great Faux-Neon Sign

August 12, 2019 by Lewin Day 11 Comments

Neon signs are attractive, but require specialised tools and skills for their manufacture. If you don’t have time to learn glass blowing and source the right gasses, you’re pretty much out of luck. However, EL wire can give a similar aesthetic, and with an off-the-shelf power supply it is easy to hook up and get working. [sjm4306] combined this with 3D printing for a quick and easy build.

The project starts by selecting a Nintendo 64 neon sign as a basis for the design. An image of the sign was traced in Inkscape, and an outline imported into CAD software. From there, a frame was designed with posts for the EL wire to wrap around, and holes for it to pass through to the back of the sign. The frame was then 3D printed, and laced with EL wires in the requisite colors.

The final result is impressive, with the EL wire serving as a great small-scale simulacrum of neon tubes. It’s a construction method that should scale as large as your 3D printed assemblies can go, too. If you need to get to grips with how it works, there’s a tutorial available for working with EL wire. Video after the break.

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That E-Cig Battery Probably Fits Into Sunglasses

August 12, 2019 by Donald Papp 20 Comments

This particular e-cigarette is a little bigger than a typical cigarette, with a matching battery.

E-cigarettes use electrical power to rapidly heat and vaporize a base liquid such as propylene glycol, and that power comes from a battery. These devices are functionally straightforward but it can be a messy process on the inside. Thankfully though the batteries can be salvaged once components like heating elements either gum up or burn out.

[facelesstech] decided to use the battery from an e-cig as the power source for a smart sunglasses project, which uses two RGB LED rings to put on a light show. Opening up the device it was discovered that the battery was a straightforward lithium-polymer cell, in AAAA size. If you’ve ever torn open a 9 v battery and discovered the six diminutive cylinders inside, an AAAA cell is about the same size as one of those. However, the battery from the e-cig is both rechargeable and has a nominal voltage of 3.7 volts, which can happily drive a microcontroller project. The small battery fit nicely into one arm of the glasses, and when covered with heat-shrink, was hardly noticeable. The battery charger doesn’t fit inside the glasses, but one can’t have everything.

The ability of an e-cigarette to pump out clouds of vapor has led to some interesting hacks. One such is a DIY portable fog machine, which opens all kinds of doors for costuming applications.

PaperLedger: An E-Ink Cryptocurrency Ticker

August 12, 2019 by Tom Nardi 6 Comments

For a long time it seemed like e-ink displays were outside the reach of us lowly hackers, as beyond the handful of repurposed Kindles that graced these pages, we saw precious few projects utilizing this relatively exotic display. But that’s changed over the last couple of years, and we’re thrilled to start seeing hackers bend this incredible technology to their will.

A perfect example is PaperLedger, an entry into the 2019 Hackaday Prize by [AIFanatic]. This wireless device is designed to display the current price of various cryptocurrencies on its 2.9-inch e-ink screen and provide audible price alerts with its built-in speaker. It even has a web portal where users can configure the hardware or view more in-depth price information.

The PaperLedger is based on the TTGO T5 V2.2 ESP32, but it looks like [AIFanatic] is in the process of spinning up a new board for the MIT licensed project to address some nagging issues for this particular application. Unfortunately, it doesn’t look like there are any pictures of the new board yet, but a description of the changes on the Hackaday.IO page shows that most of the work seems to be going into improving support for running on batteries.

Even if you’re not interested in cryptocurrency, the PaperLedger looks like a fantastic little e-ink monitor for pretty much anything else you’d like to keep a close eye on. The GPLv3 licensed firmware is available on the project’s GitHub page, so expanding or completely changing the device’s functionality shouldn’t be too tricky for anyone with a desire to do so and a working knowledge of C++.

We’ve seen several projects using the various TTGO boards that mate an ESP32 with a display at this point, and it looks like a great platform to check out if you want to push some data to a little WiFi screen with the minimum amount of hassle.