Electric Jet Engine Uses 3D Printed Compressor, Skips The Turbine Altogether.

Turbojet engines are an incredible piece of 20th century engineering that except for some edge cases, have mostly been replaced by Turbofans. Still, even the most basic early designs were groundbreaking in their time. Material science was applied to make them more reliable, more powerful, and lighter. But all of those incredible advances go completely out the window when you’re [Joel] of [Integza], and you prefer to build your internal combustion engines using repurposed butane canisters and 3d printed parts as you see in the video below the break.

Emoscopes, CC BY-SA 3.0 via Wikimedia Commons

To understand [Integza]’s engine, a quick explanation of Turbojet engines is helpful. Just like any other internal combustion engine, air is compressed, fuel is burned, and the reaction produces work. In a turbojet, a compressor compresses air. Fuel is added in a combustor and ignited, and the expanding exhaust drives a turbine that in turn drives the compressor since both are attached to the same shaft. Exhaust whose energy isn’t spent in turning the turbine is expelled and produces thrust, which propels the engine and the vehicle it’s attached to in the opposite direction. Simple, right? Right! Until the 3d printer comes in.

Sadly for 3d printed parts, they are made of plastic. Last we checked, plastic isn’t metal, and so 3d printing a turbine to give the extremely hot exhaust something turn just isn’t going to work. But what if you just skipped the whole turbine part, and powered the compressor with an electric motor? And instead of using an axial compressor with tons of tiny blades that would likely be impossible to 3d print with enough strength, you went with a sturdy, easy to print centrifugal compressor? Of course, that’s exactly what [Integza] did, or we wouldn’t be talking about it. The results are fantastic, especially considering that the entire machine was built with 3d printing and a home made spot welder.

If you want to build a full jet turbine, we won’t say it’s easy, but you might appreciate this jet turbine whose components include a toilet paper holder as proof that once a technology is understood, it can be built in the worst ways possible and still work. Sort of.


51 thoughts on “Electric Jet Engine Uses 3D Printed Compressor, Skips The Turbine Altogether.

  1. First-Very impressed and great work!. It Would be interesting to know the thrust from only the printed fan, and then the thrust energy from the completed system. Would make a great shop heater for winter.

    1. Haha exactly.. i think he needs a converging-diverging nozzle and high enough chamber pressure to drive super sonic flow to make any useful thrust out of the combustion. Otherwise its just the thrust of the compressor and the flame makes it hot

  2. Could someone please explain to me what turbofan edge cases are? When I think turbofan I am cast towards most commercial aircraft. Eg the big sellers from the big two (and others) in the commercial aircraft industry. Thanks.

      1. Even all the 4th and 5th gen fighters I can think of (I would say all, but there’s probably one exception eluding my brain) use turbofans, albeit low-bypass.

  3. So, by getting rid of the turbine, he’s effectively made a poor man’s scramjet, but gets around having to have an initial high velocity, by feeding air in with a fan.

          1. The one overriding benefit is that it’s easy to build. Which is a pretty big benefit for somebody using 3d printed parts and spot welded sheet metal.

    1. Turbine-fed ramjet would be a little more correct as the combustion isn’t happening in the supersonic regime, but as Ryan noted, motorjet is an even more correct term!

      Or as mike said, a fan with an afterburner (I wouldn’t use ducted, though, that colloquially implies an axial fan).

      It’s all semantics.

          1. Ramjets and scramjets don’t need a moving compressor to compress the intake air. They use geometry and shocks to do it without any moving parts. Just airflow, fuel injectors, and ignitors.

      1. It has a proper flame holder so it is a combustion chamber not just an afterburner (after burners just dump fuel into exhaust) As for fan vs compressor, he’d need to show us the pressure increased from inlet to outlet to be a compressor, otherwise if it just increase airflow speed that is a fan.

  4. I assume the big issue here is that you need to modulate the fuel based on the speed of the fan to make it efficient? Perhaps next project is to add microcontroller to monitor blade RPM (or maybe even airflow via MAF sensor) and solenoid to control fuel flow?

  5. Safety 101 for flammable liquid containers. Safely drain any pressurised gasses / liquid. Gravity drain for liquids heavier than air. For gasses and liquids lighter than water fill container with water to expel any remaining gasses or liquids.

    Most flammables require the oxygen from air to combust so if your going to open up car fuel (gas) tank with an angle grinder then an almost completely empty one is much more likely to blow you to bits than a full one.

    Drill bits can cause sparks. This is not a safe way to empty gas containers.

          1. Saw that happen in a novel once.

            In the story, an Australian was talking to an American. The American says he’s 5 feet, six inches tall. The Australian thinks for a moment then something like “Hmmm. 5′ 6″ is about 1.7 meters. That’s below the 1.8m meter limit. You’re too small for the job.”

            Some numpty updated the book later and “corrected” all the non-metric references to metric. That changed the Australian’s sentence to “Hmmm. 1.7 meters is about 1.7 meters. That’s below the 1.8m meter limit. You’re too small for the job.”

            Good book, bad editing.

          2. There’s also colloquialisms. When an American says “that hole must be a hundred feet deep!”, they probably don’t mean it’s exactly 100 feet, they just mean ‘its very deep’, and you’d probably die if you fell down it. However, I’ve seen this translated into French as “30m”, which really loses the original meaning.
            Fortunately in Britain we use Imperial and Metric interchangeably, so we get the best of both worlds.

      1. But what if I don’t *want* risk bringing down the Black Lectroids of Planet 10 to earth? Suddenly the whole threat of them kicking off WW3 doesn’t seem as implausible as it could have been.

        Man, that joke got away from me “hahahaha I bet the bloodhound people are so sick of this joke *inserts joke about aliens threatening to destroy the earth anyway, goes to wikipedia to double check the aliens name… sees _how_ they planned to destroy the earth* … oh yeah. oh. well. crap.”

    1. Never heard this “definition” before. A jet is just something that expels something, that’s all. What’s this nonsense about “mechanical feedback”? An engine is, by definition, an open system designed to produce energy from matter – feedback has nothing to do with it. I can’t even guess at what you meant by this even after googling.

    2. This is defined as a motorjet. Not the first one, either. A mechanical feedback loop is merely one way to produce thrust using these properties of physics. It’s a convenient one, but by far not the “only” one.

  6. Kind of sad for the environment that he just drained the cans of butane into the atmosphere. I wonder the efficiency of that compressor vs an off the shelf ducted fan

    1. Its Butane, there’s nothing sad about it. Less of a greenhouse gas impact than a human produces in, like, a day, and also it’s very biodegradable unlike most hydrocarbons.

  7. Kinda like running an internal combustion engine off it’s electric starter. It would be a mechanical feedback loop if it somewhere generated a small amount of electricity..

  8. Glad to see the Integza coverage here, wow! Been following this mad scientist/engineer for a while, he is very entertaining and doesn’t bore you with overly complicated things.

    It’s funny seeing all these people commenting on safety and practical application…. Guys he does this for entertainment and educational purposes, it’s not a DIY engineering channel lol….

  9. “A jet engine is a type of reaction engine discharging a fast-moving jet that generates thrust by jet propulsion.” so sayeth Wikipedia. Since this technically includes rockets, we tend to call something a jet if it also gets it’s air from the atmosphere rather than carrying it onboard (like a rocket).

    It only needs a turbine if you’re trying to make a *turbo*jet. The article goes into detail as to why making a *turbo*jet with 3d printed plastic parts is a non-starter, hence why the final design is a *non-turbo* jet. So there’s nothing inconsistent or incorrectly defined up there.

  10. a turbine stage can be 3D printed using powder metal – either a nickel or titanium alloy that can handle the temperature of the combustion gases. steel powder could be used, but it might be too heavy. the turbine blades in the largest jet engine, the GE9X for 777X are 3D printed of titanium aluminide and the turbine disk is forged from a nickel superalloy

  11. Cheers. You are going to help me with your creativity and improvisation towards the mankind’s extinction, avoiding the universe’s poisoning and allowing the Drakonyan ruling of this galaxy’s sector. No way to deny, we can get instantly the grip of your mind and your will. See you soon.

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