Pulsejets are a popular DIY build for the keen experimenter, much loved for their mechanical simplicity and powerful roar. However, it can be difficult to get them running smoothly and producing high amounts of thrust. In an ongoing quest to do just that, [Integza] has been iterating hard on his designs, recently adding an electric turbocharger to add some boost.
Like any combustion engine, adding more air means that more fuel can be burned for more power. The electric turbocharger is a perfect way to do this, using a powerful brushless motor to turn a radial compressor wheel to force high-pressure air into the pulse jet’s combustion chamber. [Integza] used a resin printer to produce the turbocharger compressor wheel and housing, which made producing the complex geometry a cinch.
Initial results were positive, with the pulsejet maintaining better combustion with the turbocharger activated. It does come with the drawback of requiring battery power to run, but it may be worth the tradeoff for added thrust. However, the fragile setup requires more refinement before a thrust test can be carried out. Up until now, [Integza] has made do with a set of bathroom scales; we imagine a spring force gauge or strain gauge might be in order. If you’re keen to build your own pulsejet without welding, consider the carbon fiber method used in this project. Video after the break.
Continue reading “3D Printed Turbocharger Boosts Pulsejet Performance”
With the aim of reducing virus transmission due to gatherings during the pandemic, the Dutch government have banned fireworks. The people of the Netherlands like their noisy things so we’re told that the ban has been widely flouted, but [Build Comics] are a law-abiding group of workshop tool heroes. For their lockdown noise, they created an entirely-legal pulsejet. The interesting part is that it was made entirely using fairly basic tools on a minimalist budget, with TIG and MIG eschewed in favour of a mundane stick welder.
The form of the pulse jet will probably be familiar as it has been taken from other published designs. A long tube is bent back upon itself with a combustion chamber placed in one of its arms such that the jet forms a resonant chamber that produces continuous pulses of exhaust gas. This one is made from stainless steel tube, and the exhaustive documentation should be worth a look for anyone tempted to make their own. Welding thin sheet with a stick welder requires quite a bit of skill, and in a few places they manage to burn a hole or two. One requires a patch, but the time-honoured technique of running a bead around the edge manages to successfully close another.
Their first attempt to fire it up using a leaf blower with a 3D-printed adapter fails, but following the construction of a more resilient part and a more efficient gas injector the engine starts. It’s then taken out on a farm for some serious noise without too many angry neighbours, as you can see in the video below the break.
The hero tools of Build Comics have appeared here before, most recently with an analogue meter clock.
Continue reading “A 136 Euro Pulse Jet For Some No-Firework Lockdown Fun”
Jet engines are undeniably awesome, but their inherent complexity prevents many from experimenting with the technology at home. Perhaps the most accessible design is the pulsejet; in valveless form, it can be built relatively easily without needing a lot of precision spinning parts. [Integza] decided to try building his own, facing many hurdles along the way. (Video, embedded below.)
Despite eschewing turbines and compressors, and consisting of just an intake, exhaust and a combustion chamber, the pulsejet still presents many challenges to the home gamer. Primary concerns are sustaining combustion without the jet flaming out, and building the jet out of suitable materials that won’t simply melt into a gooey puddle on the floor.
[Integza]’s design process began with many 3D-printed attempts. While the geometry was on point, none of these designs could run for more than a few seconds without melting and falling apart. Determined to avoid the typical welded-steel approach, [Integza] instead resolved to go left-of-field with carbon fibre mat combined with high-temperature sealant. With the help of a 3D-printed mold, he was able to produce a working engine that could stand up to the high temperatures and produce that glorious pulsejet sound.
It’s come a long way from [Integza]’s earlier experiments, and we look forward to seeing where it goes next – whether that be on a plane or perhaps even a go-kart. Video after the break.
Continue reading “Homebrew Pulsejet Uses Carbon Fiber To Great Effect”
[Colin Furze] is at it again. This time he’s built a freaking jet-engine powered go kart.
In case you’re not familiar with [Mr. Furze], he’s no stranger to building high-speed vehicles, like the fastest baby stroller in the world. And he’s also got a bit of an obsession with pulse jet engines. He’s even made one out of a toilet roll holder. He was a plumber — but now he’s one of the best mad scientist YouTube creators around. We just hope he doesn’t kick the bucket too soon with one of his extreme projects, because his safety tie probably won’t save him!
This month’s project is no exception — he’s strapping his giant pulse jet engine he used to fart on France onto the frame of a tiny go kart. “As you can see the jet to kart ratio is pretty good”. No kidding — the engine has gotta be 2.5 times as long as the go kart’s frame!
Stick around after the break to see him risk his neck for our own amusement.
Continue reading “Do Not Try This At Home: A Jet Powered Go Kart”
Sweden is coming out of the depths of a cold, dark winter. What better time, then, to enjoy the last few weeks of frigid temperatures, short days, and frozen lakes and rivers? That’s what Orsa Speed Weekend is all about; tearing across a frozen lake by any means necessary, including jet powered snowmobiles.
This pulse jet comes from the fruitful minds at Svarthalet Racing (Google Translation) who have put an amazing amount of work into their fuel-injected pulse jet snowmobile during these last cold winter months. They’ve even gone so far as to do some analysis regarding how much horsepower their snowmobile has. Surprisingly, it’s not much more horsepower than a small car, but that’s due to the hilarious inefficiency of pulse jets compared to more conventional engines.
This isn’t the first time we’ve seen jet powered snowmobiles build for Orsa Speed Weekend. We’ll just hope this year a few more videos will show up in our tip line.
[Colin Furze] is just showing off in this picture. His pulse jet tea kettle is built well enough to get by without help from a blow torch, but who can blame his showmanship? In fact, once it’s running there’s no flame to be seen. That’s because the combustion happens at an earlier stage of that pipe, heating a segment that is submerged in water so that you may have your tea in no time.
Once this thing is tuned up it roars like a robotic lion. [Colin] yells his commentary at the camera, but it is picked up as nothing more than a blip of distortion. Pressurized propane and air both feed into the jet. they’re regulated by the two knobs on the base of the unit (that enclosure is actually just a pie tin). There is also a 9V battery-powered igniter built into the base. You can see how the unit was built in the video after the break.
Continue reading “Pulse Jet Tea Kettle”
Imagine our surprise when we learned [Bruce Simpson], who made headlines in 2003 with his $5000 DIY cruise missile, is still alive, not illegally interned in a black ops prison, and still doing what he does best: building really awesome remote-control airplanes.
successful mass-produced pulse jet aircraft was the German V-1 flying bomb. The V-1 had a very primitive guidance system, but the unmanned pulse jet aircraft quickly evolved into a few target drones used by the US Air Force. There was never any significant advancement towards improving the fuel consumption, noise level, or heat signature of pulse jets, so they were superseded by the superior turbojet. Despite their failings, pulse jets are remarkably easy to build and amazingly fast.
Instead of being antagonized by the New Zealand and United States governments, [Bruce] spends most of his time now working on pulse jet projects. He’s flown quite a few modified R/C planes and has an electronic Engine Control Unit for his jets. One of his most impressive projects is the 100 pound thrust pulse jet that was later attached to a go-kart. His no weld version of a pulse jet can be built in even the most minimalist work shop and is the epitome of an easy-to-build jet engine.
To get an idea of how fast [Bruce]’s planes can be, check out his Long-EZ R/C pulse jet in action after the break.
Continue reading “Engine Hacks: A Pulse Jet UAV By Any Other Name Would Still Be A Cruise Missile”