Using RC Transmitters With Flight Simulators

It’s winter, and that means terrible weather and very few days where flying RC planes and helicopters is tolerable. [sjtrny] has been spending the season with RC flight simulators for some practice time. He had been using an old Xbox 360 controller, but that was really unsuitable for proper RC simulation – a much better solution would be to use his normal RC transmitter as a computer peripheral.

The usual way of using an RC transmitter with a computer is to buy a USB simulator adapter that emulates a USB game pad through a port on the transmitter. Buying one of these adapters would mean a week of waiting for shipping, so [sjtrny] did the logical thing and made his own.

Normally, a USB simulator adapter plugs in to a 3.5mm jack on the transmitter used for a ‘buddy box’, but [sjtrny] had an extra receiver sitting around. Since a receiver simply outputs signals to servos, this provides a vastly simpler interface for an Arduino to listen in on. After connecting the rudder, elevator, aileron, and throttle signals on the receiver to an Arduino, a simple bit of code and the UnoJoy library allows any Arduino and RC receiver to become a USB joystick.

[sjtrny] went through a second iteration of hardware for this project with a Teensy 3.1. This version has higher resolution on the joystick axes, and the layout of the code isn’t slightly terrible. It’s a great project for all the RC pilots out there that can’t get a break in the weather, and is also a great use for a spare receiver you might have sitting around.

Lego Avengers Assemble to the Helicarrier!

The massive engineering-defying Helicarrier from the Avengers is a brilliant work of CGI. Too bad it’d never actually fly… Like… Never.

Luckily, that didn’t stop our favorite RC hackers over at FliteTest from making a scale model of it — that actually works! If you’re not familiar, the Helicarrier is a fictional ship, the pride of S.H.I.E.L.D’s air force, or is it their navy.

It’s a massive aircraft carrier with four huge repulsor engines built into it, borrowing tech from Stark Industries. The shear size of it is what makes it completely ridiculous, but at the same time, it’s also unbelievably awesome.

Unfortunately, repulsor technology doesn’t seem to exist yet, so the FliteTest crew had to settle with a set of 8 brushless outrunner motors, with two per “engine”. The whole thing is almost 6′ long.

It doesn’t handle that well (not surprising!) but they were able to launch another RC  plane off of it, mid-flight! Landing however… well you’ll have to watch the video. Continue reading “Lego Avengers Assemble to the Helicarrier!”

R/C Wheel Loader Clears Snow, Lifts People

For some people, R/C cars just aren’t enough. [djMedic2008] has gotten his hands on a monstrous 1/5 scale wheel loader. The loader weighs in at 500lbs, and can lift up to 250 lbs. It was built several years ago as a prototype by [Richard] at Tiny Titan Earth Movers.

The design is based upon huge machines made by companies like Caterpillar and Komatsu. The 4WD system is driven a DC motor through a worm gear reduction. Bucket operation and steering are both operated by a hydraulic system driven by an electric pump. Just like the full-scale machines, the mini loader uses an articulated steering system. The front wheels are locked in place while the entire chassis bends at the middle pivot point. This allows for a much stronger solid front axle.

loader-gearAfter several years of hard life, the loader came to [djMedic] in need of some TLC. The biggest issue was that the rear axle bevel gear had lost several teeth. This gear is under enormous loads when the loader is turning. A gear made of harder steel was the easy answer. Thankfully, you can order high carbon steel bevel gears from Amazon. The repair video gives us a look at the design of the loader. The main components of the machine are welded up from steel sheet and tube stock. This means that [djMedic] won’t have a hard time finding spare parts for his machine once he puts it to work clearing snow, dirt, or anything else that gets in its way!

Click past the break to see the loader in action!

Continue reading “R/C Wheel Loader Clears Snow, Lifts People”

3D Printing RC Airplanes that Fly: An Engineer’s Chronicle

In the past, creating accurate replicas of models and fantasy objects was a task left to the most talented of cosplayers. These props need not be functional, though. [Steve Johnstone] takes replica model-building to the next step. He’s designing and building a model airplane that flies, and he’s documenting every step of the way.

Armed with a variety of 3D printing techniques and years of model-building experience, [Steve] is taking the lid off a number of previously undocumented techniques, many of which are especially relevant to the model-builder equipped with a 3D printer in the workshop.

As he continues his video log, [Steve] takes you through each detail, evaluating the quality of both his tools and techniques. How does a Makerbot, a Formlabs, and a Shapeways print stand up against being used in the target application? [Steve] evaluates a number of his turbine prints with a rigorous variable-controlled test setup.

How can we predict the plane’s center-of-gravity before committing to a physical design? [Steve] discusses related design decisions with an in-depth exploration of his CAD design, modeled down to the battery-pack wires. Though he’s not entirely finished, [Steve’s] work serves as a great chance to “dive into the mind of the engineer,” a rare opportunity when we usually discover a project after it’s been sealed from the outside.

3D printing functional parts with hobbyist-grade printers is still a rare sight, though we’ve seen a few pleasant and surprisingly practical components. With some tips from [Steve], we may complete this video journey with a few techniques that bump us out of the “novelty” realm and into a space where we too can start reliably printing functional parts. We’re looking forward to seeing the maiden voyage.

Continue reading “3D Printing RC Airplanes that Fly: An Engineer’s Chronicle”

Tiny R/C P-51D Mustang Tips the Scales at 3 Grams

Commercial R/C aircraft have been getting smaller and smaller with each passing year. In the early 2000’s, a palm-sized plane or helicopter was the dream of many an R/C enthusiast. Today, you can pick them up for around $20 USD at the local mall. The smallest models however, are still built by an elite group of modelers. Weighing in at a mere 3 grams, [Martin Newell’s] P-51D mustang model certainly puts him into that group. While the P-51’s 11.6 cm wingspan may not make it the smallest plane in the world, its many functions make it incredible.

The Mustang is an 8 channel affair, with elevator, throttle, rudder, ailerons, flaps, navigation lights, working retracts, and flashing cannon lights. That’s Wright, we did say retracts, as in retractable landing gear on a 3 gram model.

All the Mustang’s flight surfaces feature fully proportional control. However, there are no closed loop servos involved. The flight surfaces use magnetic actuators, consisting of a tiny neodymium magnet surrounded by a coil of magnet wire. We’re not sure if the signals to these actuators is straight PWM or if [Martin] is varying the frequency, but the system works. The retracts use heat-sensitive Nitinol “muscle wire” along with a bellcrank system to make sure the landing gear is up and locked after takeoff, and comes down again before a landing.

We don’t have any in-flight video of the Mustang, but we do have footage of an even smaller 1.2 gram plane [Martin] has been flying lately. Click past the break to check it out!

Continue reading “Tiny R/C P-51D Mustang Tips the Scales at 3 Grams”

A Remote Control, Swing Wing F-14

Anyone can build a remote control airplane with a sheet of foam, some glue, and a handful of servos. Building an F-14, complete with the swing wing mechanism? [Thomas] found built one that’ll take you right into the danger zone.

This was [Thomas]’ first go at scratch building a RC airplane, and wanted a lot of electronics inside. His choice of airframe was the venerable F-14 Tomcat, complete with wings that swing out for landing and swing in for high-speed flight. This isn’t just taking off-the-shelf receivers and putting them in a fancy airframe, either: [Thomas\ is reading the PWM signals from the receiver with a small electronics board, mixing the elevons with his own code, and implementing an auto stabilization system with an accelerometer.

Most of the work on the airframe was done by [Maybz] over on the RCGroups forums. That’s an impressive thread spanning seven years of posts. [Thomas] doesn’t see his F-14 as an end goal, though: he’s using this as a stepping stone to learn about building unstable planes for a more complex UAV.

Videos below, with a warning to headphone users.

Continue reading “A Remote Control, Swing Wing F-14″

Controlling a Quadcopter with Gestures

[grassjelly] has been hard at work building a wearable device that uses gestures to control quadcopter motion. The goal of the project is to design a controller that allows the user to intuitively control the motion of a quadcopter. Based on the demonstration video below, we’d say they hit the nail on the head. The controller runs off an Arduino Pro Mini-5v powered by two small coin cell batteries. It contains an accelerometer and an ultrasonic distance sensor.

The controller allows the quadcopter to mimic the orientation of the user’s hand. The user holds their hand out in front of them, parallel to the floor. When the hand is tilted in any direction, the quadcopter copies the motion and will tilt the same way. The amount of pitch and roll is limited by software, likely preventing the user from over-correcting and crashing the machine. The user can also raise or lower their hand to control the altitude of the copter.

[grassjelly] has made all of the code and schematics available via github.