Radio Controlled Hovercraft Apes The SR.N1

Hovercraft never really caught on as regular transportation, but they are very cool. The Saunders-Roe SR.N1 was the very first practical example of the type, and served as a research vehicle to explore the dynamics of such vehicles. [mr_fid] was looking for a lockdown project, and set about crafting a radio controlled replica of his own.

The build is crafted out of a canny combination of plywood and balsa, the latter substituted in sections within the plywood hull to save weight. A pair of brushless outrunner motors are mounted in the central duct to provide lift, fitted with counter-rotating propellers in order to avoid torque effects on handling. Steering is via puff ports a la the original design, which allows the craft to spin very quickly in place to much amusement and no practical effect. The skirt is of a colorful design, carefully assembled out of polyurethane-coated nylon.

While it’s not the quickest way to build a hovercraft, it’s all the more beautiful for its attention to the details and function of the original prototype craft. We particularly like the sharp handling thanks to the puff port design. If you’re looking for a weirder design however, consider this Coanda Effect build. Video after the break.

Continue reading “Radio Controlled Hovercraft Apes The SR.N1”

Ground Off Part Number Leads To Chip Detective Work

Sometimes when a piece of electronics lands on the bench, you find that its chips have their markings sanded off. The manufacturer is trying to make the task of the reverse engineer less easy, thus protecting their market. [Maurizio Butti] found an unexpected one in an electronic switch designed for remote control systems, it had the simple job of listening to the PWM signal from a receiver in a model aircraft or similar and opening or closing a FET.

From previous experience he suspected it might be a microcontroller from STC based on the location of power, ground, Rx, and Tx pins. This 8051-compatible device could be readily reprogrammed, so he has able to create his own firmware for it. He’s published the code and it’s pretty simple, as it simply replicates the original. He acknowledges that this might seem odd, but makes the point that it is left open for future upgrades such as for example repeatedly cycling the output as in a flashing light.

We don’t see so much of the STC chips here aside from one of their earlier offerings, but the 8051 core features here more regularly as it’s found in Nordic’s NRF24 series of wireless-capable chips.

Rocket Plane Build Aims For High Speed Flight

[James Whomsley] likes flying, and likes flying fast. After reaching a speed of 114 miles an hour with an RC plane, he wanted to go further and break that record. To do so, he looked towards rocket power, and started a new build.

The design consists of a combination of 3D printed parts, laser-cut plywood bulkheads, and foamboard flight surfaces, with a few carbon fiber stiffeners thrown in here and there. For this early prototype, power is solely from hobby rocket motors, providing thrust for 1.6 seconds, meaning flight times are necessarily short. The craft is launched from an aluminium profile rail thanks to a 3D printed sliding guide pin.

Initial tests with two rocket motors were promising, leading to a second trial with a full six motors fitted. The thrust line was a little low, however, and a major pitch-up just after launch meant the plane only reached around 62 miles an hour. [James] still has a ways to go to beat his previous record, so intends to explore adding ducted fan propulsion to get the plane in the air before using the rockets as a speed booster in steady flight.

Of course, if you can’t lay your hands on rocket engines, you could always consider spinning up your own. (Or ditch the engine entirely.) Video after the break.

Continue reading “Rocket Plane Build Aims For High Speed Flight”

Tesla Turbine Boat Uses Lily Impeller

Typically in the RC community, radio control boats rely on small nitro engines or electric motors to get around. Fitted with traditional propellers, they’re capable of great speed and performance. Of course, there’s more than one way to skin a cat, as [Integza] shows with his latest build.

As far as the boat side of things is concerned, it’s a basic 3D printed single hull design. The innovation comes in the drivetrain, instead. The boat uses compressed air for propulsion, stored in a battery of four soda bottles, pressurized to 6 bar. The compressed air is used to drive a Tesla turbine of [Integza]’s design, which is 3D printed on a resin printer. Rather then driving a propeller, the Tesla turbine instead turns a Lily impeller, which pulls the boat through the water rather than pushing it along. The impeller uses a nature-inspired design, hence the name, and was also 3D printed, making producing its complex geometry a cinch. The guts of a toy radio control car are then used to control the boat.

Understandably, performance is less than stellar. The limited reserves of compressed air can’t propel the boat long, and the combination of the high RPM Tesla turbine and Lily impeller don’t provide a lot of thrust. However, the boat does move under its own power, demonstrating these oddball technologies while doing so.

[Integza] has been working with these technologies for a while; we featured an earlier Tesla turbine build back in 2018. Video after the break.

Continue reading “Tesla Turbine Boat Uses Lily Impeller”

RC Car Becomes Useful Little Mower

When we think of lawn mowers, our first thought is of heavy, rusty old machines that take the best part of an afternoon to get started. Of course, there’s always another way, as [Mark] ably demonstrates with his own build. 

Beginning from an unconventional starting point, [Mark] chose a remote control car, of the type that can flip and drive in both orientations. Having lost the controller, he started by ripping out the original electronics. In its place, an ESP32 receives signals from a FlySky RC receiver, and runs the drive motors with a Sparkfun Monster Motor Shield. Another channel on the receiver is hooked up directly to a drone speed controller driving a brushless motor, outfitted with a sawblade to cut the grass.

It’s a small platform, and one that ordinarily you might doubt could do the job. However, for [Mark]’s purposes, the rig works just fine, and has been doing good work for the last two years! We’ve seen mowers hacked before too, like this autonomous rig out in the wild. Video after break.

Continue reading “RC Car Becomes Useful Little Mower”

An Epic Story Of 1980s FPV Flight

A staple of today’s remote-controlled flight is the so-called FPV transmitter, allowing the pilot of a multirotor or other craft to see the world from onboard, as a pilot might do. It’s accessible enough that it can be found on toy multirotors starting at not much more than pocket money prices, and reliable enough that in its better incarnations it can send back high definition video at surprisingly long range.

In case you think of FPV flight as a recent innovation, the video below the break from [Larry Mitschke] should come as a revelation. In 1986 he was a bona-fide rockstar playing in a band, whose radio-controlled flight hobby led him into creating an FPV system for his planes and soaring above the Texas countryside at significant distance from his base while flying it watching a CRT screen.

The video is quite long but extremely watchable, all period footage with his narration here in 2020. We see his earliest experiments with a monochrome security camera and a video sender, and a whole host of upgrades until finally he can fly three miles from base with good quality video. 70 cm amateur TV makes an appearance with a steerable tracking antenna, he even makes a talking compass for when he loses himself. It’s an epic tale of hacking with what seems rudimentary equipment by our standards but was in fact the cutting edge of available video technology at a time when the state of the video art was moving rather fast. This is the work that laid the path for today’s $30 FPV toys, and for flying FPV from space.

Continue reading “An Epic Story Of 1980s FPV Flight”

How To Slice Lightweight Aircraft Parts For 3D Printing

Historically, remote control aircraft were produced much like their early full-sized counterparts. Wooden structures were covered with adhesives and taut fabric membranes. Other techniques later came to the fore, with builders looking to foam and other materials. Of course, these days 3D printers are all the rage, so perhaps one can simply print out a whole plane? As [sahevaantaneja] discovered, it’s not that easy!

One of the foremost problems is the process of slicing. This is where 3D geometry is transformed into the G-code which defines the path taken by the 3D printer during production of a component. Slicer software is generally optimised for working with mostly-solid objects, and some tweaks can be required when working with thin-walled designs.

These challenges come to bear with an aircraft design, which, by necessity must be lightweight. [sahevaantaneja] does a great job of explaining the journey of discovery in which their design was optimised to work with conventional slicers. This allowed the various components to be printed without errors, while retaining their strength to survive in flight.

The design was successful in test flights –  a great reward after much experimentation. We’ve seen other 3D printed designs take flight, too. Video after the break.

Continue reading “How To Slice Lightweight Aircraft Parts For 3D Printing”