Building The World’s Smallest Jet Turbine By Hand

December 7, 2018 by Brian Benchoff 39 Comments

There are very few machines as complex to build as a turbojet engine. The turbine blades on a commercial airliner are grown from a single crystal of metal. The engineering tolerances are crazy, and everything spins really, really fast. All of these problems aren’t a concern for [Igor], who’s building what will probably end up being the world’s smallest turbojet engine. He’s doing it in his home shop, and a lot of the work is being done by hand. We don’t know the Russian translation for ‘hold my beer’, but [Igor] certainly does.

The design of this turbojet — as far as we can tell — is a centrifugal flow turbine, or something that’s not terribly different than the projects we’ve seen that turn the turbocharger from a diesel engine into a jet. The innovation here is using a lathe to machine the compressor stages by mounting an end mill to the headstock and the compressor blank on the cross slide, in a rotary table. It’s weird, but you really can’t argue with something that looks like it’ll work.

[Igor] has made a name for himself by creating some crazy contraptions. The most impressive, by far, is a gigantic remote controlled plane, powered by a handmade jet engine. This is an enormous fiberglass plane with a homebrew engine that spins at 90,000 RPM and doesn’t fly apart. That’s impressive by any measure.

[Igor] is posting a lot of his build process on YouTube and Instagram, including heat treating the compressor stages with a blowtorch. This is an amazing project, and even if this tiny turbine will be able to self-sustain, that’s an amazing accomplishment. You can check out a few more videos from [Igor] below.

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GE’s Engine To Reignite Civil Supersonic Flight

October 24, 2018 by Tom Nardi 110 Comments

On October 24th, 2003 the last Concorde touched down at Filton Airport in England, and since then commercial air travel has been stuck moving slower than the speed of sound. There were a number of reasons for retiring the Concorde, from the rising cost of fuel to bad publicity following a crash in 2000 which claimed the lives of all passengers and crew aboard. Flying on Concorde was also exceptionally expensive and only practical on certain routes, as concerns about sonic booms over land meant it had to remain subsonic unless it was flying over the ocean.

The failure of the Concorde has kept manufacturers and the civil aviation industry from investing in a new supersonic aircraft for fifteen years now. It’s a rare example of commercial technology going “backwards”; the latest and greatest airliners built today can’t achieve even half the Concorde’s top speed of 1,354 MPH (2,179 km/h). In an era where speed and performance is an obsession, commercial air travel simply hasn’t kept up with the pace of the world around it. There’s a fortune to be made for anyone who can figure out a way to offer supersonic flight for passengers and cargo without falling into the same traps that ended the Concorde program.

With the announcement that they’ve completed the initial design of their new Affinity engine, General Electric is looking to answer that call. Combining GE’s experience developing high performance fighter jet engines with the latest efficiency improvements from their civilian engines, Affinity is the first new supersonic engine designed for the civil aviation market in fifty five years. It’s not slated to fly before 2023, and likely won’t see commercial use for a few years after that, but this is an important first step in getting air travel to catch up with the rest of our modern lives.

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Out Of Batteries For Your Torch? Just Use A Mini Nitro Engine

July 22, 2018 by Ben James 18 Comments

We can certainly relate to an incomplete project sowing the seed for a better one, and that’s just what happened in [JohnnyQ90]’s latest video. He initially set out to create an air compressor powered by a nitro engine, and partially succeeded – air was compressed, but not nearly enough to be useful.

Instead, he changed tack and decided to use the 1 cc engine to make a small electric generator. [JohnnyQ90] is, of course, no stranger to the nitro engine, having previously brought us the micro chainsaw conversion, and nitro powered rotary tool. This time round, the build is a conceptually simple task: connect an engine to a DC motor and you’re done. But physically implementing it in an elegant way is a different story, and this is always where [JohnnyQ90] shines; we never get tired of watching him produce precision parts on the lathe. A fuel tank is made from a modified Zippo can and, courtesy of a CNC milled fan and 3D printed shroud, the motor air cools itself.

Towards the end of the video, [JohnnyQ90] plays with the throttle a little, causing the bulb connected to the generator to brighten accordingly. It might be fun to control the throttle with a servo and try to regulate the voltage on the output under different load conditions.

We love novel ways of creating electricity; previously we’ve written about how to generate power from a coke can, as well as this 120 W thermoelectric generator (TEG) setup.

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3000W Unicycle’s Only Limitation Is “Personal Courage”

April 23, 2018 by Donald Papp 38 Comments

Electric vehicles are fertile ground for innovation because the availability of suitable motors, controllers, and power sources makes experimentation accessible even to hobbyists. Even so, [John Dingley] has been working on such vehicles since about 2009, and his latest self-balancing electric unicycle really raises the bar by multiple notches. It sports a monstrous 3000 Watt brushless hub motor intended for an electric motorcycle, and [John] was able to add numerous touches such as voice feedback and 1950’s styling using surplus aircraft and motorcycle parts. To steer, the frame changes shape slightly with help of the handlebars to allow the driver’s center of gravity to shift towards one or the other outer rims of the wheel. In a test drive at a deserted beach, [John] tells us that the bike never went above 20% power; the device’s limitations are entirely by personal courage. Watch the video of the test, embedded below.

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When Stirling Engines Meet 3D Printers

April 14, 2018 by Mike Szczys 17 Comments

Let’s face it, everybody wants to build a Stirling engine. They’re refined, and generally awesome. They’re also a rather involved fabrication project which is why you don’t see a lot of them around.

This doesn’t remove all of the complexity, but by following this example 3D printing a Sterling engine is just about half possible. This one uses 3D printing for the frame, mounting brackets, and flywheel. That wheel gets most of its mass from a set of metal nuts placed around the wheel. This simple proof-of-concept using a candle is shown off in the video after the break, where it also gets an upgrade to an integrated butane flame.

Stirling engines operate on heat, making printed plastic parts a no-go for some aspects of the build. But the non-printed parts in this design are some of the simplest we’ve seen, comprising a glass syringe, a glass cylinder, and silicone tubing to connect them both. The push-pull of the cylinder and syringe are alternating movements caused by heat of air from a candle flame, and natural cooling of the air as it moves away via the tubing.

We’d say this one falls just above mid-way on the excellence scale of these engines (and that’s great considering how approachable it is). On the elite side of things, here’s a 16-cylinder work of art. The other end of the scale may not look as beautiful, but there’s nothing that puts a bigger smile on our faces than clever builds using nothing but junk.

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Delightful Electromechanical Build Of A Jet Engine Model

February 24, 2018 by Steven Dufresne 9 Comments

[InterlinkKnight]’s jet engine model is a delight to behold and to puzzle out. Many of us have been there before. We know how to build something, we know it’s not the most up-to-date approach, but we just can’t help ourselves and so we go for it anyway. The result is often a fun and ingenious mix of the mechanical and the electrical. His electric jet engine model is just that.

Being a model, this one isn’t required to produce any useful thrust. But he’s made plenty of effort to make it behave as it should, right down to adding a piece of plastic to rub against a flywheel gear in order to produce the perfect high-pitched sound, not to forget the inclusion of the flywheel itself to make the turbine blades gradually slow down once the motor’s been turned off. For the N1 gauge (fan speed gauge) he built up his own generator around the motor shaft, sending the output through rectifying diodes to a voltmeter.

But the most delightful of all has to be the mechanical linkages for the controls. The controls consist of an Engine Start switch, Fuel Control switch and a throttle lever and are all built around a rheostat which controls the motor speed. The linkages are not pretty, but you have to admire his cleverness and just-go-for-it attitude. He must have done a lot of head scratching while getting it to all work together. We especially like how flipping the Fuel Control switch from cutoff to run levers the rheostat with respect to its dial just a little, to give a bit of extra power to the engine. See if you can puzzle it out in his Part 3 video below where he removes the cover and walks through it all.

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Electric Snowblower Does The Job With 240 Volts

February 8, 2018 by Jenny List 89 Comments

In parts of the world where it snows a lot and there are requirements for homeowners to keep sidewalks clear, a personal snowblower is it seems an essential piece of equipment. They have traditionally used internal combustion engines, but electric models are also available.

[Joel Clemens] is not impressed by the commercial electric blowers available to him as an American, because their 120 V mains supply just can’t deliver the power to make an effective two-stage design. So he’s built his own using a formerly gasoline-powered blower from a garage sale, and a 240 V industrial motor.

The blower is an impressive piece of equipment even if his running it close to its own cord does look rather hazardous. But the video is also of interest for its examination of the state of access to 240 V outlets for Americans. [Joel] has one for his electric vehicles, and has made a splitter box to give him the required American-style 240 V industrial connector. He makes the point that this is becoming more common as the take-up of electric vehicles gathers pace.

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