Putting An Afterburner On An Electric Ducted Fan

Afterburners are commonly agreed to be the coolest feature of military fighter aircraft. Injecting raw fuel into the exhaust stream of a jet engine, afterburners are responsible for that red-hot flaming exhaust and the key to many aircraft achieving supersonic flight. [Integza] wanted to see if the same concept could be applied to an electric ducted fan, and set out to find out.

Of course, building an afterburner for an EDF does add a lot of complication. A flame tube was installed downstream of the EDF, fitted with a brass tube drilled carefully to act as a fuel injector. The flame tube was also fitted with an automotive glow plug in order to ignite the fuel, which was lighter refill gas straight from a can. The whole assembly is wrapped up inside a clear acrylic tube that allows one to easily see what’s happening inside with the combustion.

Results were mixed. While the fuel did combust, but in a rather intermittent fashion. In proper operation, an afterburner would run with smooth, continuous, roaring combustion. Additionally, no thrust measurements were taken and the assembly barely shook the desk.

Thus, if anything, the video serves more as a guide of how to burn a lot of lighter gas with the help of an electric fan. The concept does has merit, and we’ve seen past attempts, too, but we’d love to see a proper set up with thrust readings with and without the afterburner to see that it’s actually creating some useful thrust. Video after the break.  Continue reading “Putting An Afterburner On An Electric Ducted Fan”

3D Printed Hat Blasts The Rain Away

Some ideas are so bad that we just try them anyway, at least that seems to be [Ivan Miranda]’s philosophy. No stranger to just totally ignoring the general consensus on what you can (or at least should) or can’t make with a 3D printer, and just getting on with it, [Ivan] may have gone a little too far this time. Since umbrellas are, well, boring, why not try to keep dry with an air-curtain hat?

As you’ll see from the video, attempting to 3D print an impeller to run from a BLDC motor didn’t exactly go well. The imbalance due to imperfections in the printing process (and lack of an easy way balance it post-print) caused incredibly unpleasant (and possibly damaging) vibrations directly into his skull, not to mention the thing self-disassembling in a short time.

Not to be discouraged, he presses on regardless, substituting an electrical ducted fan (EDF), increasing the silliness-factor oh-so-little, after all as he says “I think I have a solution for all the issues — more power!”

EDFs and other kinds of ducted fans are used in many applications nowadays. Thanks to advances in rare-earth magnets enabling more powerful brushless motors, combined with cheap and accessible control systems, there has never been a better time to drop an EDF into your latest madcap idea. We have covered many ducted fan projects over the years, including this great video about how ducted fans work, which we think is well worth a watch if you’ve not already done so.

The “rain in spain, stays mainly in the plain” doesn’t actually reflect reality, as most rainfall is actually recorded in the mountainous north, rather than the central ‘plain’, But regardless, it never rains when you want it to, certainly in the Basque country where [Ivan] is based. Initial testing was done with a hose pipe, in the shop, which shows a certain dedication to the task in hand to say the least.

He does demonstrate it appearing to actually work, but we’re pretty sure there is still plenty of room for improvement. Although, maybe it’s safer to just shelve it and move on the next mad-cap idea?

Continue reading “3D Printed Hat Blasts The Rain Away”

Giant Scale RC A350 Airliner Using Carbon Fibre And 3D Printing

Large scale RC aircraft are pleasure to see on the ground and in the air, but putting in the months of effort required to build them requires special dedication. Especially since there is a real possibility it could end up in pieces on the ground at some point. [Ramy RC] is one of those dedicated craftsman, and he has a thing for RC airliners. His latest project is a large Airbus A350, and the painstaking build process is something to behold.

The outer skin of the aircraft is mostly carbon fibre, with wood internal framing to keep everything rigid. The fuselage and winglets are moulded using 3D printed moulds. These were printed in pieces on a large format 3D printer, and painstakingly glued together and prepared to give a perfect surface finish. The wing surfaces are moulded in flat section and then glued onto the frames. [Ramy RC]’s attention to detail is excellent, making all the control surfaces close as possible to the real thing, and retractable landing gear with servo actuated hatches. Thrust comes from a pair of powerful EDF motors, housed in carbon fibre nacelles.

This project has been in the works for almost 5 months so far and it looks spectacular. We’re looking forward to the first flight, and will be holding thumbs that is remains in one piece for a long time. See the video after the break for final assembly of this beast.

For the next step up from RC aircraft, you can always build your own full size aircraft in your basement. If you have very very deep pockets, get yourself a private hangar/workshop and build a turbine powered bush plane.

Thanks for the tip [tayken]! Continue reading “Giant Scale RC A350 Airliner Using Carbon Fibre And 3D Printing”

A DIY Functional F-35 Is No Simple Task

The advent of affordable gear for radio-controlled aircraft has made the hobby extremely accessible, but also made it possible to build some very complex flying machines on a budget, especially when combined with 3D printing. [Joel Vlashof] really likes VTOL fighter aircraft and is in the process of building a fully functional radio-controlled F-35B.

The F-35 series of aircraft is one of the most expensive defence project to date. The VTOL capable “B” variant is a complex machine, with total of 19 doors on the outside of the aircraft for weapons, landing gear and thrusters. The thruster on the tail can pivot 90° down for VTOL operations, using an interesting 3-bearing swivel mechanism.

[Joel] wants his model to be as close as possible to the real thing, and has integrated all these features into his build. Thrust is provided by two EDF motors, the pivoting nozzle is 3D printed and actuated by three set of small DC motors, and all 5 doors for VTOL are actuated by a single servo in the nose via a series of linkages. For tilt control, air from the main fan is channeled to the wing-tips and controlled by servo-actuated valves. A flight controller intended for use on a multi-rotor is used to help keep the plane stable while hovering. One iteration of this plane bit the dust during development, but [Joel] has done successful test flights for both hover and conventional horizontal flight.  The really tricky part will be transitioning between flight modes, and [Joel] hopes to achieve that in the near future.

The real Lockheed Martin F-35 Lightning II project is controversial because of repeated budget overruns and time delays, but the engineering challenges solved in the project are themselves fascinating. The logistics of keeping these complex machines in the air are daunting, and a while back we saw Marine ground crew 3D print components that they were having trouble procuring through normal channels.

Continue reading “A DIY Functional F-35 Is No Simple Task”

A Cyclonic Vacuum Cleaner On A Hacker’s Budget

Have you ever seen a product in the store and been shocked at what the manufacturer was trying to charge for it? Since you’re reading Hackaday, we can safely assume the answer to that question; building a homebrew version of some commercial product for a fraction of its retail price is practically a rite of passage around these parts. So it’s fitting that for his entry into the 2019 Hackaday Prize, [Madaeon] submitted the “DIYson”, an open source version of a popular high-end vacuum made by a British company who’s name you can surely guess.

As [Madaeon] explains on the project’s Hackaday.io page, the idea behind “cyclonic” vacuums is not particularly complex. Essentially, with a powerful enough blower and carefully designed chamber, the incoming air will spin around so fast that dust is pulled out by centrifugal force. The trick is getting it working on a small enough scale to be a handheld device. Especially given the energy requirements for the blower motor.

Luckily for the modern hacker, we’re living in the “Golden Age” of DIY. With a 3D printer you can produce plastic components with complex geometry, and thanks to a resurgence in remote controlled aircraft, powerful motors and high capacity lithium-ion batteries are easily obtainable. Powered by what’s essentially the hardware that would go into an electric ducted fan plane, the total cost of all the electronics for the DIYson comes in right around $60 USD. Even with a roll of printer filament added to the mix, you’re still comfortably at half the cost of the “name brand” alternative.

With some refinements, [Madaeon] hopes that this open source dust-buster will be a staple of labs and hackerspaces all over the world. Judging by the performance his early prototype shows in the video after the break, we know we wouldn’t mind having one.

Continue reading “A Cyclonic Vacuum Cleaner On A Hacker’s Budget”

A Safe, Ducted Drone With No Visible Blades

We love a good drone build here at Hackaday, but no matter how much care is taken, exposed propellers are always a risk: you don’t have to look far on the web to see videos to prove it. Conventional prop-guards like those seen on consumer drones often only protect the side of the propeller, not the top, and the same problem goes for EDFs. [Stefano Rivellini]’s solution was to take some EDFs and place them in the middle of large carbon fibre thrust tubes, making it impossible to get anywhere near the moving parts. The creation is described as a bladeless drone, but it’s not: they’re just well hidden inside the carbon fibre.

We’re impressed by the fact that custom moulds were made for every part of the body, allowing [Stefano] to manually create the required shapes out of carbon fibre cloth and epoxy. He even went to the trouble of running CFD on the design before manufacture, to ensure that there would be adequate thrust. Some DJI electronics provide the brains, and there’s also a parachute deployment tube on the back.

Whilst there’s no doubt that the finished drone succeeds at being safe, the design does come at the cost of efficiency. The power electronics needed are far more serious than we’d usually see on a drone of this size, to compensate for the extra mass of the thrust ducts and the impediment to the air-flow caused by the two 90° bends.

One of our favorite EDF drone innovations that we saw recently was this thrust-vectored single rotor device, a really unique idea that took some interesting control methods to implement.

[Thanks, Itay]

Continue reading “A Safe, Ducted Drone With No Visible Blades”

Plug Your Ears And Hop On This Jet-Powered EBike

Ah, the simple pleasures of a bike ride. The rush of the wind past your ears, the gentle click of the derailleurs as you change gears, the malignant whine of the dual electric jet turbines pushing you along. Wait, what?

Yes, it’s a jet bike, and its construction was strictly a case of “Why not?” for [Tech Ingredients]. They recently finished up a jet engine build using a hybrid design with electric ducted fans as compressors and fueled with propane. It was quite a success, and pretty spectacular, but left an embarrassment of riches upon its passing in terms of spare parts. The ducted fans, monstrous 90-mm 12s beasts, along with dual 150A ESCs found their way onto a mountain bike by way of a rear luggage rack. Pannier bags on each side hold the batteries, and a quick control panel went on the handlebar. The video below shows the build details and a couple of test rides, which show just how fast you can go with this setup. It may not be very practical compared to a more traditional hub motor, but it’s nowhere near as cool. Just be sure to wear your hearing protection.

Is this the first jet engine on a bike we’ve featured? Of course not. But for an impromptu build, it’s pretty impressive. Continue reading “Plug Your Ears And Hop On This Jet-Powered EBike”