Goliath: One Drone to Rule Them All

goliath

We see quadcopter projects all the time here on Hackaday, so it takes something special to get our attention. [Peter McCloud] has done just that with Goliath, a gas powered quadcopter he’s entered in The Hackaday Prize. By gas, we don’t mean a little glow fuel buzzer, We’re talking about a 30 horsepower V-twin lawnmower engine running good old-fashioned gasoline.

Multicopters powered by a single power source present a unique set of problems. Quadcopter propellers need to rotate in opposite directions to avoid the entire craft spinning due to torque action. With individual electric motors that’s as easy as swapping a couple of wires. Not so with a single rotating engine. [Peter] has accomplished this feat with a clever arrangement of single and double-sided belts.

Control is another issue. Generally, central powered multicopters use collective pitch, similar to a helicopter control system. [Peter] has decided to go with high-efficiency fixed pitch blades and a vane system for directional control. Much like hovercraft use vanes to steer, Goliath will use vanes to affect its attitude and yaw.

goliathPropThe propellers are works of art in their own right. [Peter] modeled the propellers in CAD using the principles of blade element theory, then used a Shopbot style CNC to carve them out of pink insulation foam. Styrofoam alone won’t withstand the 60 lbs each propeller will be supporting, so [Peter] plans to laminate the props in composite cloth. This is the similar to the way many full-scale helicopter rotor blades are assembled.

Goliath’s frame is constructed of Dexion style slotted steel angles, and we have to admit, at 240 lbs with engine, it seems like it’s going to be a heavy beast. Big enough to ride at least. Who knows… if the judges like it [Peter] may ride Goliath all the way to space!

 

 


SpaceWrencherThe project featured in this post is an entry in The Hackaday Prize. Build something awesome and win a trip to space or hundreds of other prizes.

Droning On: Choosing a Flight Controller

do4 The flight controller is the nerve center of a drone. Drone flight control systems are many and varied. From GPS enabled autopilot systems flown via two way telemetry links to basic stabilization systems using hobby grade radio control hardware, there is an open source project for you.

Modern drone flight controllers can trace their roots back to R/C helicopters. Historically, R/C planes were controlled directly by the pilot’s radio. Helicopters added a new wrinkle to the mix: tail rotors. Helicopters use their tail (or anti-torque) rotor to counteract the torque of the main rotor attempting to spin the entire helicopter’s body. It all works great when the helicopter is hovering, but what about when the pilot throttles up to fly out? As the pilot throttles up, the torque increases, which causes the entire helicopter to do a pirouette or two, until the torque levels out again. The effect has caused more than one beginner pilot to come nose to nose with their R/C heli.

The solution to this problem was gyroscopes, heavy brass spinning weights that tilted in response to the helicopter’s motion. A hall effect sensor would detect that tilt and command the tail rotor to counteract the helicopter’s rotation. As the years wore on, mechanical gyros were replaced by solid state MEMS gyros. Microcontrollers entered the picture and brought with them advanced processing techniques. Heading hold gyros were then introduced. Whereas older “rate only” gyros would drift, weathervane, and wiggle, heading hold gyros would lock down the helicopter’s nose until the pilot commanded a turn. These single axis flight controllers were quickly adopted by the R/C helicopter community.

Today’s flight control systems have many sensors available to them – GPS, barometric pressure sensors, airspeed sensors, the list goes on. The major contributors to the flight calculations are still the gyros, coupled with accelerometers. As the name implies, accelerometers measure acceleration – be it due to gravity, a high G turn, or stopping force. Accelerometers aren’t enough though – An accelerometer in free fall will measure 0 G’s. Turning forces will confuse a system trying to operate solely on accelerometer data. That’s where gyros come in. Gyros measure rate of rotation about an axis. Just as our helicopter example above covered yaw, gyros can be used to measure pitch and roll of an aircraft. A great comparison of gyros and accelerometers is presented in this video from InvenSense.

Stay with us after the break for a tour of available flight controllers and what each adds to the mix. [Read more...]

Chocolate Quadrotor Proves You Can Make Anything Fly

Chocolate Quadrotor

With the advancements in quadrotor parts and technology over the years, it’s become possible to make just about anything fly if you can strap some high-speed rotors to it. Introducing the first edible quadrotor!

[Michael] enjoys building and flying quadrotors. His girlfriend enjoys baking and making chocolates. One day she had a crazy idea — what if they made a quadrotor together, combining their unique skill sets? [Michael] was a bit skeptical at first. After all, chocolate doesn’t really compare to aluminum or carbon for a frame material… and chocolate melts at room temperature. Regardless — they were curious enough to try it out and see for sure.

First they built a wooden prototype and then created a silicone mold from it. Using Styrofoam and metal spacers for the electronics mounts they filled the mold with chocolate and let it set. A bit of assembly later and they had a chocolate quadrotor. It flies too.

[Read more...]

Analog Shield and PCB Quadcopter

 

We spent a little bit of time at the TI booth at Maker Faire to film a pair of interviews. The first is with [Bill Esposito] who is grinding away on his PhD. at Stanford. He’s showing off an Analog Shield for Arduino. He describes it as “an attempt to bring the analog bench to an Arduino shield”. We think this is a fantastic idea as most who are learning digital electronics through Arduino have little or no experience with analog circuitry. This is a nice gateway drug for the concepts.

The analog shield has a supply good for +/- 7.5 volts, 4-channel ADC, 4-channel DAC, and gets 100k samples at 16-bits. He showed us a spectrum analyzer using Fast Fourier Transform on the incoming signal from a microphone. He also built a function generator around the shield. And finally a synthesizer which plays MIDI files.

In the second half of the video we take a look at [Trey German's] work on a PCB-based quadcopter. His goal is to reduce the power consumption which will equate to longer flying times. To this end he chose the DRV8312 and a Piccolo to control each sensorless, brushless DC motor. The result should be 10% lower power consumption that his previous version.

 

A Huge, Lightweight Wooden Quadrotor

quad_1

[Robert] once built a quadcopter frame by sawing laminate floor tile. It worked, we’re taking the lack of pictures of this build as evidence of how ugly it was. His latest design used a much better looking material – laser cut plywood – and the finished product is very strong and lightweight, even compared to commercial frames made with glass or carbon fiber and epoxy.

Although the design went smoothly thanks to some Solidworks skills, actually cutting the frame from 3mm birch ply resulted in a few issues. The cheap laser cutter used for cutting include some bottom of the line software called LaserWorksV5. There is a kerf compensation feature, called ‘sew compensation’ in the software’s native Chinglish. The software would always crash whenever it tried to calculate the compensation for circles. [Robert] spent two hours figuring this problem out, and in the end needed to break out a piece of sand paper to get a nice interlocking fit.

The completed frame bolts together without any glue at all, and the best part about it is the weight – only 167 grams. Compare that to a similarly sized glass fiber frame, and [Robert]‘s shaved at least 200 grams off his finished build.

Frankensteined X4 Quad is Brought Back to Life

x4 quadcopter wood frame

As kids we’ve all let a friend use a toy only to have it returned broken. That was such a bummer! At least that was years ago though…. well not for [Tom]. He had a Hubsan X4 mini quadcopter that he had crashed into all sorts of things. The little quad held up good against all of the beatings so [Tom] didn’t think too much about letting his pal take it for a test drive. Thirty seconds later, several separate pieces of the quad were laying in the dirt.

A new X4 was ordered but there was some time to kill waiting for it to show up. Since the electronics seemed to be intact and only the frame was broken [Tom] decided to try his hand at making a new frame. Keeping costs under control is an important part of any project and this one was no different. The frame would be made of cheap and rigid 5mm plywood. The only potential problem would be the weight. [Tom] cut out a piece of the plywood and weighed it, then measured the volume and calculated the density of the wood. The wood’s density was used to estimate the final weight of new plywood frame designs and shapes. This worked so well that the newly built quad only weighed more than the original by 0.31 grams, less than 1% increase in the total weight!

[Read more...]

A Quadcopter from Scratch

Quadcopter

[AwesomeAwesomeness] wanted a low cost quadcopter, so he built one from scratch. Okay, not quite from scratch. [AA's] cookie mix came in the form of an Arduino Uno and some motors. He started with motors and propellers from a Hubsan X4 quadcopter. Once the power system was specified, [AA] designed a frame, arms, and motor pods in Solidworks. He printed his parts out and had a sweet quadcopter that just needed a brain.

Rather than buy a pre-made control board, [AA] started with an Arduino Uno.  An Arduino alone can’t source enough current to drive the Hubsan motors. To handle this, [AA] added a ULN2003A  Darlington transistor array. The 2003A did work, but [AA] had some glitching issues. We think FETs would do much better in this application, especially when running PWM.

On the control side of things, [AA] added an MPU-6050 Triple Axis Accelerometer and Gyro breakout from SparkFun. The 6050 has 3 gyros and 3 accelerometers in one package. Plenty for a quadcopter.

All this left was the coding. Multicopters generally use Proportional-Integral-Derivative (PID) control loops to maintain stability in the air. [AA] used the Arduino PID library for his quadcopter. He actually created two PID instances – one for pitch and one for roll.

[AA] doesn’t have any videos of his quadcopter in action yet, and we’re guessing this is due in part to weight. Lifting an Uno, a perfboard, and a frame is a tall task for those motors. Going with a one of the many tiny Arduino’s out there would help reduce weight. In addition, [AA] could use a gear system similar to what is used in the Syma X series quadcopters. Stick with it – you’re on the right track!

 

Follow

Get every new post delivered to your Inbox.

Join 93,941 other followers