K.C.'s Garage

I was doing some fast, straight line FPV flying with one of my quadcopters and a few things struck me about how multicopters fly in a straight (horizontal) line; The more you pitch forward (to go faster) the less aerodynamic you are The angle of the pitch actually serves to reduce lift, effectively fighting the motors Finding the maximum forward speed is a risky, manual process. So what if you wanted to build a multicopter optimized for forward flight?  I've seen some 250mm FPV racers that actually had the front two motors angled forward to increase the forward speed at a lower pitch angle.  I found myself asking - what if you could dynamically actuate the front motors forward instead of pitching the whole aircraft?  (Similar to the motors on an Osprey, but sans wings.) Vectored thrust on multirotors is uncommon, but not new.  Still, this idea has a singular purpose which makes working out the details and controls a bit easier. So, I decided to build one....

Update :  Have one?  Building one?   Click Here: Donkey Quad Manual A while ago I bought an inexpensive HobbyKing F330 frame, thinking I would use it with some SunnySky X2212-9 1400KV motors and 8" props I had.  Unfortunately, that turned out to be a very unstable combination.  It was fast as hell, and good at aerobatics, but I couldn't tune the shakes out of it.  I decided those motors were just too big for that small 330mm frame. On a whim, I was looking at the cheapest 3S capable outrunners that HobbyKing sells when I ran across these ugly duckings here: The Donkey ST2004-1550kv , "When pulling power matters and looks.. well.. just don't." HobbyKing Donkey ST2004-1550kv The mounts are nonstandard ugly aluminum tangs with holes in them.  The sticker oddly says "ST2204-1550kv" whereas the website part number os "ST2004-1550kv".  They have 3mm shafts, but don't include any collets or prop adapters. But, they're dirt ch...

I had the EDFs mounted to the frame with zip ties for the first test.  That proved a bit unstable.  I also had the problem of the motor housings sticking down lower than the rest of the quad, which posted a threat to them on landing. Talon motor mount So, I decided to kill two birds with one stone by making some EDF mount brackets that extended vertically below the bottom of the motor housings.  The Turnigy Talon frame I used included these aluminum "T" mounts, intended to be mounted horizontally at the end of the tubular arms to allow you to mount the motor on top.  I simply turned them 90 degrees so that the flat face was vertical to align them with one of the two flanges protruding from the side of the EDF housings. To mount the EDF flanges to them, I fabricated a mounting bracket to use as a clamp.  I used an old license plate frame that I cut into four equal length parts and drilled matching holes in: Four mounts cut from a discarded license pla...

I decided, against conventional "wisdom", to construct a quadcopter that uses Electric Ducted Fans (EDFs) for thrust.  There is conjecture all over the internet as to why this is a bad idea, but I was having a hard time finding any real science or performance data to back it up.  So, why not build one and see what happens? What are EDFs? EDFs are basically small, higher pitch, higher rpm propellers (sometimes called "impellers" in this application, to differentiate them from conventional propeller design) inside a cylindrical duct with a tapered inlet and as little clearance between the blades and the duct wall as possible.  They look more like jet engines than conventional propellers.  Tangent: Modern jet engines actually are turbine driven ducted fans, called " turbofans ." The primary benefit of a ducted fan is increased efficiency of the propeller by preventing (or reducing) the phenomenon of "tip vorticies" and allowing a greater ra...

A common question I get is:  "What MultiWii flight controller should I use?" There are a few determining factors involved in this decision.  The primary considerations are: What microcontroller (µC) do you need What integrated sensors do you want? What Microcontroller (µC) should you look for? MultiWii is based on the Atmel corporation's 8 bit "megaAVR" series of µCs.  All the MultiWii boards I've seen are based on one of three µCs, but you could certainly port the software to others if you're good at microcontroller integration. Below is a table of the three most common and their relevant specifications: µC flash ram eeprom serial uarts usb ports ATmega328p 32 kilobytes 2048 bytes 1024 bytes 1 0 ATmega32u4 32 kilobytes 2560 bytes 1024 bytes 1 1 ATmega2560 256 kilobytes 8192 bytes 4096 bytes 4 1 Those of you who are familiar with AVR µCs will notice I left off the number of digital, ...

Meet "Sharky", my first non-indoor quadcopter.   (Shown next to one of my brushed-motor nano quads for scale.) I wanted to graduate to a larger quad, but not something huge, so I decided this 345mm span "mini" quad was the way to go.  I liked the size and design of this quad. The "pseudo-airplane" shape on the frame looked more like a shark than an aircraft to me, hence the name. We'll start with what I initially built: Frame: Turnigy Integrated PCB Mini-Quad 345mm Flight Controller:  MultiWii MicroWii ATmega32U4 Flight Controller USB/BARO/ACC/MAG Receiver:  OrangeRx R100 Spektrum/JR DSM2 Compatible Satellite Receiver 4 x Motors:  Turnigy Park300 Brushless Outrunner 1380kv 4 x Speed Controllers (ESCs):  Afro ESC 12Amp (SimonK Firmware) Battery:  ZIPPY Compact 2200mAh 3S 25C Lipo Pack Props: GWS HD8040 3 blade (& their counter rotating counterparts ) I fly this with my existing OrangeRX T-Six DSM2 transmitter. I run MultiWii 2....

Anyone who knows me well knows that lately I've been playing with remote-controlled flying things.   This post provides information and links to the small (nano) indoor flyable quadcopters I've been playing with. I have built & modified a few quadcopters of various (small) sizes, from the tiny brushed-motor nano-quads like the HobbyKing Pocketquad & Syma X1 to a larger, more traditional brushless motor mini quad based on the Turnigy 345mm frame.  (More on that in a subsequent post.) Throughout this endeavor I've been using (and customizing) the MultiWii flight control software , with various Arduino / Atmel-based flight control boards.  It's becoming a FAQ what hardware and systems I'm using, so in this post I'll detail my current setup.  Future posts will cover updates, new hardware, and a couple of crazy projects I'm working on.  ;) Note: I buy a lot of parts made and sold by HobbyKing.com in China.  Their website is a bit... odd.. so I...