3D Printed Turbocharger Boosts Pulsejet Performance

February 10, 2021 by 34 Comments

Pulsejets are a popular DIY build for the keen experimenter, much loved for their mechanical simplicity and powerful roar. However, it can be difficult to get them running smoothly and producing high amounts of thrust. In an ongoing quest to do just that, [Integza] has been iterating hard on his designs, recently adding an electric turbocharger to add some boost.

Like any combustion engine, adding more air means that more fuel can be burned for more power. The electric turbocharger is a perfect way to do this, using a powerful brushless motor to turn a radial compressor wheel to force high-pressure air into the pulse jet’s combustion chamber. [Integza] used a resin printer to produce the turbocharger compressor wheel and housing, which made producing the complex geometry a cinch.

Initial results were positive, with the pulsejet maintaining better combustion with the turbocharger activated. It does come with the drawback of requiring battery power to run, but it may be worth the tradeoff for added thrust. However, the fragile setup requires more refinement before a thrust test can be carried out. Up until now, [Integza] has made do with a set of bathroom scales; we imagine a spring force gauge or strain gauge might be in order. If you’re keen to build your own pulsejet without welding, consider the carbon fiber method used in this project. Video after the break.

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Simple Slide Whistle Gets A MIDI Makeover

February 10, 2021 by 7 Comments

On today’s episode of “Will it MIDI?” we have the common slide whistle. Spoiler alert: yes, it will, and the results are just on the edge of charming and — well, a little weird.

As maker [mitxela] points out, for all its simplicity, the slide whistle is a difficult instrument to play. Or, at least a difficult one to hit a note repeatably. It’s a bit like a tiny plastic trombone, in that both lack keys or stops that limit the vibrating column of air to a specific length. Actually, the beginning of the video below shows a clever fix for that problem on the slide whistle using magnets, but that’s mainly a side project.

[mitxela]’s MIDI-fication of the slide whistle required a bit more than a few magnets. To move the slide to defined positions, a pair of high-precision servos was connected by a laser-cut plywood scissors linkage. The lung-power of the musician is replaced by a small electric blower, mounted away from the whistle and supplying air through a long hose. The fan’s speed, and therefore the speed of the airflow, can be varied; this prevents low notes from shifting up in register from over-blowing, if that’s the right term. Another servo controls a damper that shuts off the flow of air from the mouth of the whistle to control notes without having to turn off the fan completely. The main article goes into detail about the control electronics and the calibration process.

The video has a few YouTube copyright strikes demo songs, and we have to say we’re impressed with the responsiveness of the mechanism. Some will object to the excess servo noise, but we found it nice — almost like guitar string-squeak. We like the tunes where [mitxela]’s servo-plucked music box joined in, too.

The $50 Ham: Digital Modes With WSJT-X

February 10, 2021 by 33 Comments

As it is generally practiced, ham radio is a little like going to the grocery store and striking up a conversation with everyone you bump into as you ply the aisles. Except that the grocery store is the size of the planet, and everyone brings their own shopping cart, some of which are highly modified and really expensive. And pretty much every conversation is about said carts, or about the grocery store itself.

With that admittedly iffy analogy in mind, if you’re not the kind of person who would normally strike up a conversation with someone while shopping, you might think that you’d be a poor fit for amateur radio. But just because that’s the way that most people exercise their ham radio privileges doesn’t mean it’s the only way. Exploring a few of the more popular ways to leverage the high-frequency (HF) bands and see what can be done on a limited budget, in terms of both cost of equipment as well as the amount of power used, is the focus of this installment of The $50 Ham. Welcome to the world of microphone-optional ham radio: weak-signal digital modes.

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Basic In 10 Lines Or Less

February 10, 2021 by 17 Comments

For the last 11 years [Gunnar Kanold] has run the annual BASIC 10 Liner contest, and the rules for the 2021 edition are now available. There are four categories and each category has specific definitions of what constitutes a line. All entries must run on an 8-bit computer system that can be emulated.

The first three categories are for games but differ in the line length allowed. You can elect to compete with 80 character lines, 120 character lines, or 256 character lines. There’s also a category for demos, tools, and other applications that must constrain lines to 256 characters.

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Would You Like Fries With Your Insect Burger, Ma’am?

February 10, 2021 by 167 Comments

A trip to a supermarket is a rare luxury in a pandemic lockdown, but were I to cruise the aisles with my basket today I’d probably come away with a healthy pile of fruit and veg, a bit of meat and fish, and maybe some cheese. My shopping basket in 2031 though might have a few extras, and perhaps surprisingly some of them might be derived from insects. That’s a future made a little closer, by EU scientists declaring that farmed insect products are safe for humans and animals to eat.

Global map showing meat consumption in 2013
Is meat consumption at this level sustainable? Our World In Data, CC BY 3.0.

We humans, like some of our fellow great ape cousins, are omnivores. We can eat anything, even if we might not always want to eat some things twice. As such, the diets of individual populations would in the past have varied hugely depending on the conditions that existed wherever they lived, giving us the ability to spread to almost anywhere on the planet — and we have.

Over the past few hundred years this need to subsist only on foods locally available has been marginalized by advances in agriculture. For those of us in developed countries, any foodstuff that takes our fancy can be ours for a trivial effort. This has meant an explosion of meat consumption as what was once a luxury food has become affordable to the masses, and in turn a corresponding agricultural expansion to meet demand that has placed intolerable stresses on ecosystems and is contributing significantly to global warming. It’s very clear that a mass conversion to veganism is unlikely to take place, so could farmed insects be the answer to our cravings for meat protein? It’s likely to be a tough sell to consumers, but it’s a subject that bears more examination. Continue reading “Would You Like Fries With Your Insect Burger, Ma’am?” →

Android 10 Ported To The Nintendo Switch

February 10, 2021 by 3 Comments

Nintendo’s Switch is perhaps most famous for blurring the lines between handheld consoles and those you plug into a TV. However, the tablet-esque device can also run Android if you’re so inclined, and it recently got an upgrade to version 10.

It’s an upgrade that brings many new features to the table, most of which you might consider must haves for regular use. The newer port brings support for USB Power Delivery, as well as deep sleep modes that enable the unit’s battery to last for several weeks. There’s also support for over-the-air updates which should ease ongoing maintenance, and improvements for Bluetooth compatibility and the touch screen as well.

Like most console hacks to run custom code, you’ve got to have the right hardware version with the right firmware, as Nintendo have been regularly iterating to try and lock out hacks where possible. The install has a few hurdles to jump through, but nothing too strenuous that would scare away the average Hackaday reader. Just be sure to not attempt this on a cherished console, as there’s always the chance that it all ends in tears. If you pull it off, you can then go about turning your Nintendo Switch into a networking switch. Net…tendo… Switch? Come up with a better pun in the comments. Continue reading “Android 10 Ported To The Nintendo Switch” →

3D Printer? Laser Cutter? CNC? Yes, Please

February 10, 2021 by 60 Comments

Most of us have, or, would like to have a 3D printer, a laser engraver, and a CNC machine. However, if you think about it naively, these machines are not too different. You need some way to move in the XY plane and, usually, on the Z axis, as well.

Sure, people mount extruders on CNCs, or even lasers or Dremel tools on 3D printers. However, each machine has its own peculiarities. CNCs need rigidity. 3D printers should be fast. Laser engravers and CNCs don’t typically need much Z motion. So common sense would tell you that it would be tough to make a machine to do all three functions work well in each use case. [Stefan] thought that, too, until he got his hands on a Snapmaker 2.0.

As you can see in the video below, the machine uses different tool heads for each function. The motion system stays the same and, curiously, there are three identical linear motion modules, one for each axis.

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