Probably the most efficient way to convert solar energy into electricity is the old fashioned way, heating water into steam and turning a turbine. This remains a messy affair though and you don’t really want a steam boiler on your roof, so solar cells are popular. However, there’s some new research showing how a molecule can absorb solar energy, store it, and then release the heat on demand years later. This could offer new ways to collect and even transport solar power. This new molecule, derived from azobenzene, holds immense promise to change the way we work with solar power.
It seems as though every week we see something that clearly shows we’re living in the future. The components we routinely incorporate into our projects would have seemed like science fiction only a few short years ago, but now we buy them online and have them shipped to us for pennies. And what can say we’ve arrived in the future more than off-the-shelf plasma thrusters for the DIY microsatellite market?
Although [Michael Bretti] does tell us that he plans to sell these thrusters eventually, they’re not quite ready for the market yet. The AIS-gPPT3-1C series that’s currently under testing is designed for the micro-est of satellites, the PocketQube, a format with a unit size only 5 cm on a side – an eighth the size of a 1U CubeSat. The thrusters are solid-fueled, with blocks of Teflon, PEEK, or Ultem that are ablated by a stream of plasma. The gaseous exhaust is accelerated and shaped by a magnetic nozzle that’s integrated right into the thruster. The thruster is mounted directly to a PCB containing the high-voltage supplies and control electronics to interface with the PocketQube’s systems. The 34-gram thrusters have enough fuel for perhaps 500 firings, although that and the specifics of performance are yet to be tested.
If you have any interest at all in space engineering or propulsion systems, [Michael]’s site is worth a look. There’s a wealth of data there, and reading it will give you a great appreciation for plasma physics. We’ve been down that road a lot lately, with cold plasma, thin-film plasma deposition, and even explaining the mystery of plasmatic grapes.
Thanks to [miguekf] for the tip.
When life hands you the world’s smallest chainsaw, what’s there to do except make it even more ridiculous? That’s what [JohnnyQ90] did when he heavily modified a mini-electric chainsaw with a powerful RC car engine.
The saw in question, a Bosch EasyCut with “Nanoblade technology,” can only be defined as a chainsaw in the loosest of senses. It’s a cordless tool intended for light pruning and the like, and desperately in need of the [Tim the Toolman Taylor] treatment. The transmogrification began with a teardown of the drivetrain and addition of a custom centrifugal clutch for the 1.44-cc nitro RC car engine. The engine needed a custom base to mount it inside the case, and the original PCB made the perfect template. The original case lost a lot of weight to the bandsaw and Dremel, a cooling fan was 3D-printed, and a fascinatingly complex throttle linkage tied everything together. With a fuel tank hiding in the new 3D-printed handle, the whole thing looks like it was always supposed to have this engine. The third video below shows it in action; unfortunately, with the engine rotating the wrong direction and no room for an idler gear, [JohnnyQ90] had to settle for flipping the bar upside down to get it to cut. But with some hacks it’s the journey that interests us more than the destination.
This isn’t [JohnnyQ90]’s first nitro rodeo — he’s done nitro conversions on a cordless drill and a Dremel before. You should also check out his micro Tesla turbine, too, especially if you appreciate fine machining.
Old cars are great. They represent a different time, reflecting the state of society at the point of their design and manufacture, and can charm and delight while also providing useful transport. Except, well… old cars are great, except when they’re not.
With my Volvo 740 hitting its thirtieth birthday and cresting over 200,000 miles, to say its a little worse for wear is an understatement. The turbo dadwagon has suffered transmission issues, and cold starting woes… but most frustrating is the sudden spike in fuel use. After some work, my humble daily driver had slid from using an acceptable 21 miles per gallon, to getting just 15. Add on the fact that the turbocharged engine demands premium fuel, and you can understand my consternation.
Now that I was haemorrhaging cash on a gargantuan weekly fuel bill, I had plenty of motivation to track down the problem. Busy, and eager for a quick solution, I deferred to a mechanic recommended as the local expert in all things Volvo. Sadly, the results were inconclusive — initial appearances were that all the engine’s electronic controls were functioning to specifications, and I was told that it was “probably a bad batch of fuel”.
Unfortunately, several expensive tanks later, sourced from all over town, revealed that the problem was in fact real. With a supposedly reliable report that the fuel mixture was correct, thus ruling out culprits like the oxygen sensor, I began to wonder, was I simply pouring fuel out the tank?
Many of us made soda bottle rockets for science class. Some of us didn’t have that opportunity, and made them in the backyard because that’s what cool kids do. Water rockets work on the premise that if water is evacuated from one side of a container, the container will accelerate away from the evacuation point. Usually, this takes the form of a 2-liter bottle, a tire pump and some cardboard fins. [François Gissy] modified the design but not the principle for his water trike which reached 261 kph or 162mph.
Parts for the trike won’t be found in the average kitchen but many of them could be found in a motorcycle shop, except for the carbon fiber wrapped water tank. There wasn’t a throttle on this rocket, the clutch lever was modified to simply open the valve and let the rider hold on until the water ran out. The front brake seemed to be intact, thank goodness.
Powering vehicles in unconventional ways is always a treat to watch and [François Gissy]’s camera-studded trike is no exception. If you like your water rockets pointed skyward, check out this launch pad for STEM students and their water rockets. Of course, [Colin Furze] gets a shout-out for his jet-powered go-kart.
Thank you, [Itay], for the tip.
On today’s edition of ‘don’t try this at home,’ we’re transported to Russia to see [Igor Negoda]’s working jet bicycle.
This standard mountain bike comes equipped with a jet engine capable of 18kg of thrust, fixed to the frame under the seat with an adjustable bracket to change it’s angle as needed. A cell phone is zip-tied to the frame and acts as a speedometer — if it works, it’s not stupid — and an engine controller displays thrust, rpm and temperature. A LiPo battery is the engine’s power source with a separate, smaller battery for the electronics. The bike is virtually overgrown with wires and tubes that feed the engine, including an auxiliary fuel tank where a water bottle normally resides. Where’s the main fuel tank? In [Negoda]’s backpack, of course.
It certainly kicks up a mean dust cloud and makes a heck of a racket but the real question is: how fast does it go? From the looks of the smartphone, 72 km/h, 45 mph, or 18 rods to the hogshead.
In specific applications, jet engines are often the most efficient internal combustion engines available. Not just for airplanes, but for anything that needs to run on a wide variety of fuels, operate at a consistent high RPM, or run for an extended amount of time. Of course, most people don’t have an extra $4,000 lying around to buy a small hobby engine, but now there’s a 3D-printed axial compressor available from [noob_sauce].
As an aero propulsion engineer, [noob_sauce] is anything but a novice in the world of jet engines. This design is on its fourth iteration with a working model set to be tested by the end of the month. Additionally, [noob_sauce] created his own software that was necessary for the design of such a small, efficient jet engine which has all been made available on Git. So far the only part that has been completed has been the compressor stage of the engine, but it’s still a very impressive build that we don’t see too often due to the complexity and cost of axial compressor jet engines.
Of course, there are some less-complex jet engines that are available to anyone with access to a hardware store and a welder which don’t require hardly any precision at all. While they’re fun and noisy and relatively easy to build, though, they don’t have near the efficiency of a jet engine like this one. The build is impressive on its own, and also great that [noob_sauce] plans to release all the plans so that anyone can build one of these as well.