The Birotary Engine Explained https://hackaday.com/2025/12/28/the-birotary-engine-explained/
#EngineHacks #Pistonengine #Rotaryengine
#enginehacks
A Two-Stroke Engine Made From Scratch Using Basic Hardware Store Parts https://hackaday.com/2024/08/05/a-two-stroke-engine-made-from-scratch-using-basic-hardware-store-parts/ #internalcombustionengine #EngineHacks #machining
Making EV Motors, And Breaking Up with Rare Earth Elements https://hackaday.com/2024/07/09/making-ev-motors-and-breaking-up-with-rare-earth-elements/ #Electricmotor #EngineHacks #rare-earth #ev
3D Printed Axial Compressor is On a Mission to Inflate Balloons https://hackaday.com/2024/01/29/3d-printed-axial-compressor-is-on-a-mission-to-inflate-balloons/ #EngineHacks #compressor #TechHacks #3dprinted #balloon #inflate #axial
Unbricking Trains, Uncovering Shady Behavior https://hackaday.com/2023/12/28/unbricking-trains-uncovering-shady-behavior/ #ReverseEngineering #reverseengineering #EngineHacks #locomotive #can-bus #train #cons
Machining a Reciprocating Solenoid Engine https://hackaday.com/2023/11/22/machining-a-reciprocating-solenoid-engine/ #infrareddetector #infraredemitter #solenoidengine #reciprocating #enginetiming #EngineHacks #cylinder #engine
3D Printed Engine Gets Carburetor https://hackaday.com/2023/08/30/3d-printed-engine-gets-carburetor/ #EngineHacks #valvetiming #carburetor #3dprinted #alcohol #damage #engine #valves #head
3D Printing a Carburetor Is Easier Than You Probably Think
We've all been there. You see a cool gadget on the Internet to 3D print and you can't wait to fire up the old printer. Then you realize it will take 8 different prints over a span of 60 hours, chemical post-processing, drilling, exotic hardware, and paint to get the final result. [Peter Holderith's] carburetor design, however, looks super easy.
If you have experience with real-world carbs, you might wonder how that would work, but as [Peter] points out, carburetors are very simple at the core -- nothing more than a venturi. All the extra pieces you think of are for special cases and not necessary for basic operation. We doubt, though, that you could really use the thing in its current form in your car. There are no mounts and since he printed it in PLA, it seems like a hot engine would be a bad idea. However, it does work well with water and an electric blower.
[Peter] mentions that with some more work and the right material, he has no doubt he could create a working practical carb. We think he's right. But even in this form, it is a great educational project for a budding car enthusiast -- like the old transparent V8 engine models, maybe.
Speaking of transparent, we've seen -- or maybe not seen is a better phrase -- a see-through carburetor that is also a good demonstrator. If you could perfect a 3D printed carb, it would make conversion projects a lot easier.
When you think of ethanol, you might think of it as a type of alcohol, not alcohol itself. However, in reality, it is the primary ingredient in adult beverages. Which means humans have gotten quite good at making it, as we've been doing for a long time. With this in mind, [Sam Barker] decided to make ethanol out of apples to power a small engine to charge his phone.
The steps for making pure ethanol is quite similar to making alcoholic cider. A friend of [Sam's] had an orchard and a surplus of apples, so [Sam] boiled them down and stored the mush in jugs. He added activated dry yeast to start the fermentation process. A dry lock allowed the CO2 gas that was being created to escape. Over a few weeks, the yeast converted all the sugar into ethanol and gas. In the meantime, [Sam] sourced a chainsaw and adapted the engine to run on ethanol, as ethanol needs to run richer than gasoline. The video below the break tells the story.
With his solution at just 15% ethanol, he needed to distill it to get pure ethanol for the engine to run. With a little bit of handwaving due to UK laws, [Sam] soon had a 94% ethanol solution. The next step was to use a mechanical sieve, which absorbed the water but not ethanol. He secured the engine and generator to an old cutting board, and [Sam] was ready for the first test. Fine-tuning the right throttle and choke took a while, but [Sam] had it going consistently when he ran into a snag; the phone wasn't charging. He revved the engine up, and his little charge regulator exploded. His multimeter probes were backward when he had measured the generator, and it was outputting a negative voltage. With the board swapped, the phone was charged. But [Sam] saw over 50 volts coming off the motor at times. So like most of here at Hackaday, he wanted to see how fast/high/far it could go. This ultimately fried the motor.
If you're interested in modifying generators to suit your particular fuel needs, we have generators running on natural gas, ammonia, and even your own feet.
#chemistryhacks #enginehacks #engin #ethanol #generator #phonecharger
Home Made Stirling Engines From Expedient Materials
Many of us have read about Stirling engines, engines which form mechanical heat pumps and derive motion from the expansion and contraction of a body of air. A very few readers may have built one, but for many they remain one of those projects we'd rather like to try but never quite have the inclination. The YouTube channel of [Geral Na Prática] should provide plenty of vicarious enjoyment then, with the construction of a range of Stirling engines from commonly available materials. We have Coke cans, PVC pipe, and nebuliser cartridges forming pistons and cylinders, with wire wool serving as a regenerative heat store. The latest video is below the break, an amazing 10-cylinder rotary device.
The Stirling engine is perhaps the quintessential example of a device whose time never came, never able to compete in power and efficiency with first steam engines and then internal combustion engines, it has over the years been subject to a variety of attempted revivals. Today it has appeared variously in solar power projects and in NASA's hypothetical off-world power plants, and will no doubt continue to be promoted as an alternative energy conversion mechanism. We've featured many working model Stirling engines in our time and even done a longer investigation of them, but sadly we've yet to see a story involving a practical version.
Our thanks to [TheFinn] for the tip!
A V2 Rocket Inspired Steam Turbine Skateboard Is Just Around The Corner
[Integza] never fails to amuse with his numerous (and sometimes really sketchy) attempts to create usable thrust, by pretty much all means possible and the latest video (embedded below) attempting to run a reaction turbine from decomposing hydrogen peroxide, doesn't fail to disappoint. The inspiration came from the WWII V2 rocket, which used Sodium Permanganate to breakdown Hydrogen Peroxide. This produced high pressure steam, which spun a turbine, which in turn drove the turbopumps that delivered the needed huge quantity of alcohol and liquid oxygen into the combustion chamber.
After an initial test of this permanganate-catalysed reaction proved somewhat disappointing (and messy) he moved on to a more controllable approach — using a catalytic converter from a petrol scooter in place of the messy permanganate. This worked, so the next task was to build the turbine. Naturally, this was 3D printed, and the resulting design appeared to work pretty well with compressed air as the power source. After scaling up the design, and shifting to CNC-machined aluminium, it was starting to look a bit more serious. The final test shows the turbine being put through its paces, running from the new precious metal catalyst setup, but as can be seen from the video, there is work to be done.
There appears to be a fair amount of liquid peroxide passing through into the turbine, which is obviously not desirable. Perhaps the next changes should be the mount the catalyser vertically, to prevent the liquid from leaving so easily, as well as adding some baffling to control the flow of the liquid, in order to force it to recycle inside the reaction vessel? We can't wait to see where this goes, hopefully the steam-turbine powered skateboard idea could actually be doable? Who knows? But we're sure [Integza] will find a way!
With steam power, there's more than one way to get usable rotational work, like using a reciprocating engine, which can be expanded to a whole machine shop, and whilst boiling water (or catalytically decomposing Hydrogen Peroxide) provides high pressure gas, how about just using boiling liquid nitrogen? Possibly not.
#enginehacks #3dprinted #catalyst #cncmachined #hydrogenperoxide #reactionturbine #steamengine
Gravity-Water-Air Powered Engine
Air engines are a common occurrence here on Hackaday. They're relatively novel and reasonably easy to 3D print without requiring any fluids or supporting machinery. For example, [Tom Stanton] took a previous air engine design, did away with the air compressor, and instead used gravity and water to create just a few PSI to run the engine.
The basic setup is to have a large jug of water up somewhere high. Flexible tubing runs down to [Tom's] custom acrylic pressure chamber. A little CNC-ing and some epoxy made a solid chamber, and we're happy to report that [Tom] did some initial simulation before construction to make sure he wasn't accidentally building a bomb. Some back of the napkin math showed that he could expect around 0.6 bar (around eight psi) with his setup. His first test showed almost precisely that. Unfortunately, [Tom] ran into some issues despite the early success. His engine would stop as it drew air and the pressure dropped, and the replenishing rate of the pressure was limited by the relatively small inlet hole he had drilled.
To fix this, he printed a larger diaphragm for the engine, so the lower air pressure had more to push against. This allowed the engine to run for a good while before the tank filled up. Additionally, he smoothed and polished everything, so it was as low friction as possible. We know we often state it here, but it is incredible what can be achieved with 3D printed parts these days.
We love seeing the iteration evident in this video. The various engine versions splayed across the table offer a powerful story about [Tom's] persistence. Powering an engine is a small step to powering your whole home.
#3dprinterhacks #enginehacks #3dprinted #airengine #cnc #compressedairengine #waterpower
DIY Prony Dyno Properly Displays Power Production
When hackers in the US think of a retailer called Harbor Freight, we usually think of cheap tools, workable but terrible DVM's, zip ties, and tarps. [Jimbo] over at [Robot Cantina] looked at the 212cc "Predator" engine that they sell and thought "I bet I could power my Honda Insight with that." And he did, successfully! How much power did the heavily modified engine make? In the video below the break, [Jimbo] takes us through the process of measuring its output using a home built dyno.
The dyno that [Jimbo] has built is a Prony Dyno, and it's among the oldest and simplest designs available. A torque arm is extended from a disk brake caliper and connects to a force gauge. The engine is ran up to its highest speed, and then he brake is applied to the crankshaft until the engine almost stalls. A tachometer keep track of the RPM, and the force gauge measures the force on the torque arm. Torque is multiplied by RPM and the result is divided by a constant of 5252, and voilà: Horsepower. A computer plots the results across the entire range, and the dyno test is complete.
That only tells part of the story, and the real hack comes when you realize that the dyno stand, the force gauge setup and pretty much everything that can be built at home has been built at home. You'll also enjoy seeing the results of some driving tests between the 212cc engine and its bigger 420cc brother, how even minor changes to the engine affect the horsepower and torque curves, and how that affects the Honda that he calls his "Street legal go cart."
Speaking of unusual power plants, how about plant some hobby sized jet turbines on the back of your Tesla for fun?
#enginehacks #212cc #dynamometer #dyno #engine #harborfreight #horsepower #pronydyno #torque
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.
Swap The Laser For A Vortex Cannon And You Have… Lift?
When people are thinking of the future of space travel, an idea that floats around is a spaceship with a giant solar sail pushed along by a massive laser. Inspired by the concept but lacking a giant laser, [Tom Stanton] build a small craft powered by a vortex cannon.
Creating a vortex is hard enough, but creating a vortex with enough oomph to travel a longer distance and push something takes some doing. [Sam] started with some cheap solenoids, but had a few issues. Their interior nozzles were quite small, which restricted airflow. He used four valves all plumbed together to provide the volume of air needed. Additionally, he found that their response time was lacking. They couldn't quite switch off quickly enough so instead of a puff of air, it pushed out something closer to a stream. To compensate, [Sam] 3d printed and tried a few different sizes of cone nozzles to see if that helped. Unfortunately, it did not. So he combined the nozzle with an expansion chamber that allowed the pressure wave to shorten, then it narrows to speed it up again. This provided a decent vortex.
Next [Sam] turned to his craft. After designing a 3d model, he had a template to cut out some shapes from paper and taped them together to form a light vehicle that can capture the vortex. The initial tests weren't too promising as the craft twisted and the string that it traveled on had too much friction. Switching to a vertical test showed more promise but trying to generate multiple vortexes rapidly was unsuccessful as the turbulence from the previous rings broke up the newer rings.
So what's to be learned from this? It seems like he doesn't have much to show. [Sam] tweaked and iterated his way to a working vortex cannon and has continued to refine his craft. Hopefully, in the future, we'll see a fully-functional version of this. The lesson is to keep enumerating the possibilities. Like this webcam based posture sensor iterating its way to success. Video after the break.
#3dprinterhacks #enginehacks #iteration #propulsion #vortexcannon #vortextube
Rotary Valve Engine Gets a Second Chance, Smokes The Competition
It's a dedicated hacker who has the patience to build an engine from scratch. And it's a borderline obsessed hacker who does it twice. [Meanwhile In the Garage] is of the second ilk, and in the video below the break, he takes a failed engine design and musters up the oomph to get it running.
The whole build began with an idea for a different kind of intake and exhaust valve. [Meanwhile In the Garage] dreamed up a design that does away with the traditional poppet valve. Instead of valves that open by being pushed away from their seat by a camshaft, this design uses a cylinder that is scooped so that as it rotates, its ports are exposed to either the intake or the exhaust.
Four Stroke Cycle with Poppet valves. Courtesy Wikipedia, CC BY-SA 3.0
During the compression stroke, the valve cylinder becomes part of the combustion chamber, with both ports facing away from the piston. If you read the comments, you'll find that multiple people have come up with the idea through the years. With his mill, lathe, and know-how, [Meanwhile In the Garage] made it happen. But not without some trouble.
The first iteration resisted all valiant attempts at getting it started. The hour-long video preceding this one ended up in a no-start. Despite his beautiful machine work and a well thought out design, it wasn't to be. Fire came from the engine either through the exhaust or the carburetor, but it never ran. In this version, several parts have been re-worked and the effect is immediate! The engine fired up nicely and even seems to rev up pretty well. Being a first-generation prototype, it lacks seals and other fancy parts to keep oil out of the combustion chamber. Normal engine oil has been added to the fuel as a precaution as well. The fact that it smokes quite badly isn't a surprise and only proves that the design will benefit from another iteration. Isn't that true for most prototypes, though?
Home-grown engines aren't a new thing at Hackaday, and one of This Author's favorite jet turbines used a toilet paper holder. Yes, really. Thanks to [Keith] for the Tip!
#enginehacks #4stroke #diyengine #gasoline #machining #ottocycle #rotaryvalve
There’s a Wrinkle In This 3D Printed Wankel
Rotary engines such as the Wankel have strange shapes that can be difficult to machine (as evidenced by the specialized production machines and patents in the 70s), which means it lends itself well to be 3D printed. The downside is that the tolerances, like most engines, are pretty tight, and it is difficult for a printer to match them. Not to be dissuaded, [3DprintedLife] designed and built a 3D printed liquid piston rotary engine. The liquid piston engine is not a Wankel and is more akin to an inside-out Wankel. The seals are on the housing, not the rotor itself, and there are three "chambers" instead of two.
The first of many iterations didn't run. There was too much friction, but there were some positive signs as pressure was trapped in a chamber and released as it turned. The iterations continued, impressively not using any o-rings to seal, but instead standing each part down using a 1-2-3 block as a flat reference, within 25 microns of the design. Despite his care and attention to detail, it still couldn't self-sustain. He theorizes that it could be due to the resin being softer than other materials he has used in the past. Not to be left empty-handed, he built a dynamo to test his new engine out. It was a load cell and an encoder to measure speed and force. His encoder had trouble keeping up, so he ordered some optical limit switches.
This engine is a follow-on to an earlier 3D printed air-powered Wankel rotary engine, and we're looking forward to part two of the liquid piston series. Video after the break.
How Can 335 Horses Weigh 63 Pounds?
Koenigsegg, the Swedish car company, has a history of unusual engineering. The latest innovation is an electric motor developed for its Gemera hybrid vehicle. The relatively tiny motor weighs 63 pounds and develops 335 horsepower and 443 lb-ft of torque. Dubbed the Quark, the motor uses both radial and axial flux designs to achieve these impressive numbers.
There is a catch, of course. Like most EV motors, those numbers are not sustainable. The company claims the motor can output peak power for 20 seconds and then drops to 134 horsepower/184 lb-ft of torque. The Gemera can supplement, of course, with its internal combustion engine -- a 3 cylinder design.
The motor uses advanced materials including hollow carbon fiber to reduce weight. The company believes the motor will also find use in marine and aerospace applications. They also announced the availability of a drive unit consisting of two Quarks and a planetary gear shaft that can produce 670 horsepower in 187 pounds.
Weight-to-power ratio for electric motors is tricky because you might not include the weight of the batteries and other supporting equipment. Still, this seems like a lightweight and small powerhouse.
The last time we looked in on Koenigsegg, they were 3D printing production vehicles. We imagine the Quark won't be cheap, but it would be a great crate engine.
The Air Multiplier Fan Principle, Applied To A Jet Engine
Many readers will be familiar with the Dyson Air Multiplier, an ingenious bladeless fan design in which a compressor pushes jets of air from the inside edge of a large ring. This fast-moving air draws the surrounding air through the ring, giving the effect of a large conventional fan without any visible moving parts and in a small package. It's left to [Integza] to take this idea and see it as the compressor for a jet engine, and though the prototype you see in the video below is fragile and prone to melting, it shows some promise.
His design copies the layout of a Dyson with the compressor underneath the ring, with a gas injector and igniter immediately above it. The burning gas-air mixture passes through the jets and draws the extra air through the ring, eventually forming a roaring jet engine flame exhaust behind it. Unfortunately the choice of 3D print for the prototype leads to very short run times before melting, but it's possible to see it working during that brief window. Future work will involve a non-combustible construction, but his early efforts were unsatisfactory.
It's clear that he hasn't created the equivalent of a conventional turbojet. Since it appears that its operation happens when the flame has passed into the center of the ring, it has more in common with a ramjet that gains its required air velocity with the help of extra energy from an external compressor. Whether he's created an interesting toy or a useful idea remains to be answered, but it's certainly an entertaining video to watch.
Meanwhile, this isn't the first project we've seen inspired by the Air Multiplier.
Thanks [Baldpower] for the tip.
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