3D Printed Turbofan Features Reverse Thrust

[Harcoreta] has created a 3D printed model of the GE GEnx-1B Turbofan. This is the engine that powers Boeing’s 787 dreamliner. What sets this model apart is that it has a complete working reverse thrust system. A real jet engine would be asking a bit much of 3D printed ABS plastic. This model is more of an Electric Ducted Fan (EDF). An NTM 1400kv 35mm brushless motor hides in the core, cooled by a small impeller.

jet-nakedWhat sets this apart from other jet models is the working reverse thrust system. [Harcoreta] painstakingly modeled the cascade reverse thrust setup on the 787/GEnx-1B combo. He then engineered a way to make it actually work using radio controlled plane components. Two servos drive threaded rods. The rods move the rear engine cowling, exposing the reverse thrust ducts. The servos also drive a complex series of linkages. These linkages actuate cascade vanes which close off the fan exhaust. The air driven by the fan has nowhere to go but out the reverse thrust ducts. [Harcoreta’s] videos do a much better job of explaining how all the parts work together.

The model was printed on an Reprap Prusa I3 at 0.1mm layer height. [Harcoreta] smoothed his prints using acrylic thinner, similar to the acetone vapor method. Unfortunately, [Harcoreta] has only released a few of the design files on rcgroups, but we’re hoping he will drop the whole model. We can’t wait to see a model dreamliner landing just like the big boys!

Continue reading “3D Printed Turbofan Features Reverse Thrust”

Hackaday Tours Northrop: Space Telescopes and Jet Planes

I was invited to tour the Northrop Grumman Aerospace Systems campus in Los Angeles this spring and it was fantastic! The Northrop Grumman lists themselves as “a leading global security company” but the project that stole my heart is their work on the James Webb Space Telescope (JWST) for NASA. On the one hand, I don’t see how it could possibly be pulled off as the telescope seems to cram every hard engineering challenge you can think of into one project. On the other hand, Northrop (plus NASA and all of their subcontractors) has been doing tough stuff for a very long time.

How Do You Tour Northrop Grumman?

This opportunity fell in my lap since [Tony Long] is a Hackaday reader and an engineer at Northrop. He’s the founder of their FabLab (which I’ll talk about a bit later) and was so bold as to send an email asking if one of the crew would like to stop by. Yes Please!

I was already headed out to the Supplyframe offices (Hackaday’s parent company) in Pasadena. [Tony] offered to pick me up at LAX and away we went to Redondo Beach, California for an afternoon adventure.

James Webb Space Telescope: Everything Hard About Engineering

James Webb Space Telescope (JWST)

I had heard of the James Webb Space Telescope (JWST) but had never looked closely at the particulars of the project. Above you can see a scale model which Northrop built. I didn’t actually see this on my tour. It travels to different places, taking two semi trucks, with a dozen people spending four days to set it up each time. And that’s a not-real, relegated to the surface of the planet, item. What is it going to take to put the real one into space?

It’s not just going into space. It’s going to the second Lagrangian point. This is past the moon, about 1.5 million kilometers from the earth. If this thing breaks we can’t go out there and fix it. There’s a lot of pressure for success.

The main problem facing this satellite is heat. It will use a mirror array to harvest infrared radiation from very distant astronomical bodies. For this to happen it needs to have a very good optical array to gather infrared light and focus it on a collector, and it must be isolated from the heat of the sun, earth, and moon.

There is an array of 18 hexagonal mirrors which reflect the infrared onto a collecting mirror and in turn to the sensors. These mirrors are not made by Northrop, but they did have a prototype on display and it was incredible! Each mirror is made by Ball Aerospace out of beryllium. The concave surface is coated in gold for reflectivity and an actuator mounted on the back of each mirror can flex the surface to adjust the concavity and thereby the focal length. This is in addition to the ability to adjust the roll and pitch of each segment.

In the Northrop high bay they were working on the mounting system for these mirrors. It showed much more progress than the two images seen above. This is the central mount structure for the optics. The width of this structure is dictated by the size of the rocket which will launch it into space. When I saw it, folding wings had been added to either side of this main structure to host a dual-row of mirrors which are folded back into the telescopes during its storage position. The black material itself is a composite manufactured by Northrop. The cross-section they showed as an example was not much thicker than your fingernail but obviously quite rigid in the cast pipe shape.

You can see an animation of the unfolding process which was playing in the high-bay viewing room during the tour. Note the five-layer heat shield that needs to automatically unfold without snagging. This reminds me of [Ed van Cise’s] recollection of solar panel unfolding issues on the ISS. It’s a tough problem and it looks like much time has been spend making sure this design learns from past issues. That animation doesn’t show too many details about the mirror mechanics. I found video demonstrating how the mechanical part of the mirrors work to be quite interesting.

Learning more about what goes into the James Webb Space Telescope project is worth a lot of your time. I’m not joking about this including everything hard about engineering. The challenges involved in meeting the specification of this telescope are jaw-dropping and I’m certain the people working on the project across many different companies will make this happen.

Hackerspace Driving Corporate Culture


It was nice that [Tony] and his colleague [Adam] came right out and told me they reached out to Hackaday because they want to get the message out that Northrop is rejuvenating their corporate culture. They’re in the process of hiring thousands of engineers and part of this process is making the job fit with the lifestyle that these engineers want.

One big move in this direction is the formation of their FabLab. [Tony] is an engineer but 50% of his workload is tending to the FabLab. This is basically a hackerspace open to any of the roughly 20k employees at this particular location. Northrop fabricates amazing things, and when equipment is no longer used, the FabLab gets dibs on it. Imagine the possibilities!

unexploded-armament-removalPart of this initiative is to get more engineers learning about the fabrication process. [Tony] used the example of researching by fabricating a simple proof-of-concept in the FabLab. This is an avenue to that buzzword: fail-fast. Before getting your department on board with what might be a costly and time-consuming project you can test out some of the parts which are a little hazy in your mind.

The device seen here is the product of a challenge that one of the groups participated in last year. They had about six months to develop a robot which can clear unexploded armaments. It was hanging out in one part of the hackerspace and is a great build. You can just make out a blue sphere hiding in the underbody. That’s a huge jamming gripper powered by the black and yellow shop-vac perched atop the chassis. The robot is remote controlled, with wireless GoPro cameras mounted all around and underneath. Of course the thing wouldn’t be complete without a giant silver air-horn. Safety first!

It will be interesting to see if the FabLab can build the kind of grass-roots community often associated with standalone hackerspaces. You can get a glimpse at the grand opening of the space in this video. We don’t quite remember seeing a hackerspace marketed in this manner. But if that’s what it takes to get the company on board it’s well worth it. A huge space, amazing tools, and no monthly membership fee make for a sweet deal. Oh, and the name FabLab apparently came from their mascot, the Fabulous Labrador, who can be seen in the clip wearing a string of pearls.

F/18 Assembly Plant


We wrapped up the day by touring the F/A 18 E/F Super Hornet assembly line. This is a huge plant. I don’t know how to better describe the sheer size of the assembly line than saying it took no less than twenty minutes to walk back to the parking lot at the end of this tour.

00036301Northrop Grumman serves as the principal subcontractor for Boeing on this project, so the end of the line isn’t quite a fully assembled airplane. But the fuselage — less cockpit, nose, wings, and engines — is still a formidable sight. I’ve never been this close to a fighter jet before and the size is impressive. Equally impressive is the building housing the line, which was build in 1942 and is still wood-framed to this day. They have huge engineered columns which have since been reinforced with steel. But that fact makes it no-less impressive.

The top concern during assembly is FOD, or Foreign Object Detection. These vehicles are exposed to huge forces and vibrations that will shake anything that’s not supposed to be there loose, and that can mean horrible damage to an expensive machine or much worse. Some of the things I found really interesting were the systems in place to make sure no part goes missing. All components come in cases that have an individual cutout area for each. Tools are scanned to each employee, if broken or worn out there are vending machines throughout the plant keeping track of them through a computerized system.

As part of the tour we walked through the composites plant next door. There are massive autoclaves for curing the resins. These are like a pipe sitting on its side with hemispherical doors on each end. I’m a poor judge of time and distance but I’d estimate these to be 18 feet in diameter and at least 35 feet long. Traditional composite fabrication — a worker laying down sheets of carbon-fiber on a mold — were under way. But the room next door housed a robot that looked like it was born in The Matrix. The spider-like head works next to a turning mandrel fitted with the form of the piece being fabricated. It lays out about seven strands of carbon fiber, building up a part that has no seams whatsoever. After curing the resin the mold is removed manually, piece by piece, from the inside of the part. To me the parts being built looked like air intake channels approximately 15 feet long and maybe 5 feet in diameter, although they were winding and not exactly cylindrical in shape. I wasn’t able to get very many details about them, but I was told these parts are for the F-35 Joint Strike Fighter. This is another subcontract Northrop Grumman has for Lockheed Martin.


Thank you to [Tony Long] and [Adam Gross] for spending to give Hackaday this tour. I had the impression that I was living an episode of one of my favorite programs How It’s Made, and that was awesome! Northrop Grumman has an educational outreach program so if you’re associated with a school in the area set up a tour of the JWST!

[Tony] ducked out with me for dinner; some excellent tacos — a quest I’ve been on during each visit to LA. He joined me afterward on a trip to Null Space Labs for their open night. They had moved since the last time I was there and if you’re in town you should check it out.


One thing I should mention is that I was not able to take any photographs on the premises. My story above is original but all the photos are stock or provided by Northrop at my request.

Main Post Image via JWST Flickr

Front Mirror via YouTube thumb.

Extended Reflection Mirror via YouTube video.

Retrotechtacular: The Jet Story

A plane from Britain is met in the US by armed security. The cargo? An experimental engine created by Air Commodore [Frank Whittle], RAF engineer air officer. This engine will be further developed by General Electric under contract to the US government. This is not a Hollywood thriller; it is the story of the jet engine.

The idea of jet power started to get off the ground at the turn of the century. Cornell scholar [Sanford Moss]’ gas turbine thesis led him to work for GE and ultimately for the Army. Soon, aircraft were capable of dropping 2,000 lb. bombs from 15,000 feet to cries of ‘you sank my battleship!’, thus passing [Billy Mitchell]’s famous test.

The World War II-era US Air Force was extremely interested in turbo engines. Beginning in 1941, about 1,000 men were working on a project that only 1/10 were wise to. During this time, American contributions tweaked [Whittle]’s design, improving among other things the impellers and rotor balancing. This was the dawn of radical change in air power.

Six months after the crate arrived and the contracts were signed, GE let ‘er rip in the secret testing chamber. Elsewhere at the Bell Aircraft Corporation, top men had been working concurrently on the Airacomet, which was the first American jet-powered plane ever to take to the skies.

In the name of national defense, GE gave their plans to other manufacturers like Allison to encourage widespread growth. Lockheed’s F-80 Shooting Star, the first operational jet fighter, flew in June 1944 under the power of an Allison J-33 with a remarkable 4,000 pounds of thrust.

GE started a school for future jet engineers and technicians with the primary lesson being the principles of propulsion. The jet engine developed rapidly from this point on.

Continue reading “Retrotechtacular: The Jet Story”

Hacklet #13 – Chopper Royalty


This week’s Hacklet focuses on two wheeled thunder! By that we mean some of the motorcycle and scooter projects on Hackaday.io.

hondaskyWe’re going to ease into this Hacklet with [greg duck’s] Honda Sky Restoration. Greg is giving a neglected 15-year-old scooter some love, with hopes of bringing it back to its former glory. The scooter has a pair of stuck brakes, a hole rusted into its frame, a stuck clutch, and a deceased battery, among other issues. [Greg] already stripped the body panels off and got the rear brake freed up. There is still quite a bit of work to do, so we’re sure [Greg] will be burning the midnight 2 stroke oil to complete his scooter.

jetbikeNext up is [Anders Johansson’s] jaw dropping Gas turbine Land Racing Motorcycle. [Anders] built his own gas turbine engine, as well as a motorcycle to go around it. The engine is based upon a Garrett TV94, and directly powers the rear wheel through a turboshaft and gearbox. [Anders] has already taken the bike out for a spin, and he reports it “Pulled like a train” at only half throttle. His final destination is the Bonneville salt flats, where he hops to break the 349km/h class record. If it looks a bit familiar that’s because this one did have its own feature last month.

firecoates[GearheadRed] is taking a safer approach with FireCoates, a motorcycle jacket with built-in brake and turn signal indicators. [GearheadRed] realized that EL wire or LED strip wouldn’t stand up to the kind of flexing the jacket would take. He found his solution in flexible light pipes. Lit by an LED on each end, the light pipes glow bright enough to be seen at night. [GearheadRed] doesn’t like to be tied down, so he made his jacket wireless. A pair of bluetooth radios send serial data for turn and brake signals generated by an Arduino nano on [Red’s] bike. Nice work [Red]!

[Johnnyjohnny] rounds out this week’s Hacklet with his $1000 Future Tech Cafe Racer From Scratch. We’re not quite sure if [Johnny] is for real, but his project logs are entertaining enough that we’re going to give him the benefit of the doubt. Down to his last $1000, [Johnny] plans to turn his old Honda xr650 into a modern cafe racer. The new bike will have electric start, an obsolete Motorola Android phone as its dashboard, and a 700cc hi-comp Single cylinder engine at its heart. [Johnny] was last seen wandering the streets of his city looking for a welder, so if you see him, tell him we need an update on the bike!



That’s it for this week. If you liked this installment check out the archives. We’ll see you next week on The Hacklet – bringing you the Best of Hackaday.io!

Riding rockets and jets around the frozen wastes of Sweden

An attentive reader tipped us off to the guys at Mobacken Racing (translation), a group of Swedes dedicated to the art and craft of putting jet and rocket engines on go karts and snowmobiles.

One of the simpler builds is a pulse jet sled. Pulse jets are extremely simple devices – just a few stainless steel tubes welded together and started with a leaf blower. The simplicity of a pulse jet lends itself to running very hot and very loudly; the perfect engine for putting the fear of a Norse god into the hearts of racing opponents.

Pulse jets are a bit too simple for [Johansson], so he dedicates his time towards building a jet turbine engine. Right now it’s only on a test stand, but there’s still an awesome amount of thrust coming out of that thing, as shown in the video after the break.

In our humble opinion, the most interesting build is the 1000 Newton liquid fuel rocket engine. The liquid-cooled engine guzzles NOX and methanol, and bears a striking resemblance to liquid fuel engines we’ve seen before. Sadly, there are no videos of this engine being fired (only pics of it strapped to a go-kart), but sit back and watch a couple other hilariously overpowered engines disturbing a tranquil sylvan winter after the break.

Edit: [Linus Nilsson] wrote in to tell us while the guys at Mobacken Racing are good friends, [Linus], his brother, and third guy (his words) are responsible for the pulse jet sled. The pulse jet is actually ‘valved’ and not as simple as a few stainless steel tubes. The pulse jet isn’t started by a leaf blower, either, but a four kilowatt fan. [Linus]’ crew call themselves Svarthalet racing, and you can check out the Google translation here.

Continue reading “Riding rockets and jets around the frozen wastes of Sweden”

Tailgating this car carries a heavy penalty

This hack seems simple enough:

  1. 1. Open hatchback
  2. 2. Insert jet engine
  3. 3. Profit

Actually, the guy who added a jet engine to a VW Beetle has a PhD in Mechanical Engineering from Stanford. He claims this is street legal, and even has a snapshot of the police trying to figure out what to charge him with after stopping him on the road. There’s plenty of details and we’re not questioning [Ron Patrick’s] competence, but having the intake for the turbine inside the cab of the vehicle seems a bit insane. He remarks that “it’s a little windy but not unbearable”… yeah.

One the same page you’ll find his dual-jet modified scooter. The starting cost there is considerably less, especially if you build your own ram jets.

[Thanks Goldscott]

Sukhoi Su-27 Jet build throws down

This no model, but a fully functioning RC jet. The Sukhoi Su-27 was the Soviet Union’s counterpart of the F15 and this 1/6.5 scaled version measures eleven feet long and is fully controllable. As if the 80-page build log wasn’t enough, the flight video after the break is nothing short of jaw-dropping. The test flights end in smooth landings but with all the time that went into the project that’s got to be nerve-wracking.

Continue reading “Sukhoi Su-27 Jet build throws down”