So i built myself a quadcopter in january 2014. Instead of buying a Ready-To-Fly multicopter, I plunged into building my own and it isn’t difficult as long as you choose a nice flight controller and have a bit of experience remote controlled things and know how to use a soldering iron. I went with the popular DJI Naza controller with a GPS module and gathered the rest of the parts from scrap in my workshop and on cheap hong-kong-based websites. I Planned and sketched the design in Google Sketchup during christmas 2013 while i waited for the motors and the ESCs to arrive in the mail. I milled the parts i needed on my Probotix Fireball CNC and 3d printed some parts on my Makerbot Thing-o-matic. Total hours of build was probably about 20-30 hours in my workshop, and most of them drawing in sketchup and milling parts, waiting for the 3d-prints or soldering up cables. I also built two voltage regulator circuits with a 7805 (5volt) and a 7812(12 volt) for powering the electronics that didn’t like 14.8Volt from the 4Cell lipo battery, mounted the voltage-regulators directly to the aluminum frame for cooling, and soldered everything together at my workshop.
The quadcopter has an unbalanced frame with the two front arms pointing away from the camera in front to make sure the camera doesn’t film the propellers or arms. At first i was a bit afraid of the unbalanced frame being a problem in the air, but the DJI Naza controller fixes everything and really gives a smooth controllable flight in GPS mode.
The multicopter was a success and had about 25 hours of flight-time until its life ended with a fatal bird-strike in one propeller at 100 meters altitude over a large empty field.
This is the last picture of the quad, about 3 minutes before it hit a bird!
If you want to see a video of it racing around in the night-time, check this out.
Click here for a flight video of the copter visiting IKEA
So the copter worked beautiful until it had a bird-strike in mid-air crashlanded in a tiny river far, far away. Recovery-mission was launched but just as the Malaysian flight 370 that disappeared the day before the crash, the multicopter went into stealth mode and was never seen again. The river is definitely muddy and location of impact is unclear. I considered to go home and get my drysuit and divegear but the visibility is really down to zero in that muddy water and its probably full of chemicals as well so a new episode of “aircraft investigations” will have to wait. The expensive parts is not recoverable after being soaked in water so i wrote the copter off as a nice working (and expensive) first prototype.
Here is the build log of my copter as well as some hard learned lessons and a lot of pictures of the build.
watch the youtube video of the first flight and a picture in picture showing the videolink range from 200 meters away inside a building.
Here is the part list:
Aluminium frame, cnc milled with square alu profiles and a lot of 3x30mm machine screws.
4 x 30Amp ESC from rctimer.com
4 pieces of 2210 930kv brushless motors from deal extreme.com
4 pieces of 10x 4.5 propellers from deal extreme.com
old power cables from a defect computer power supply
3-4 Deans power plugs, both male and female from deal extreme.com
12V x 1meter RGB Led-strip from Sparkfun (some leftovers from another project)
Spektrum AR9020 9-Channel DSMX/XPlus Receiver
I use a Spektrum DX9 radio for all my copters.
DJI Naza M V2 with GPS module
Lipo 4C 4200mAh with deans plug (400grams)
Tarot 2d gopro Gimbal with Gopro hero 3 black
Videolink from rangevideo.com 800mW 1.2Ghz transmitter and patch antenna receiver and a homebuiilt ground station with a SmallHD DP1X monitor in a Pelicase.
The Tarot gimbal and Gopro hero 3 with video link was not connected when it happened, so the only big loss was the electronics, cheap motors, escs, propellers and the chassis and probably a bird that lost some feathers. Dji Naza M V2 controller with GPS module and a Spektrum 9 channel carbonfibre transmitter with two extra antennas was the most expensive lesson in this crash.
Lessons learned so far during my hours of flight-time with my homebuilt quad.
When the quad was fully loaded with stuff it weight in about 1.8kg and i got around 13 minutes of flight-time with the 2212 motors with 10″ 4.5 propellers on the 4Cell 4200mAh lipo. Cutting down cable lengths and redesigning the chassis would improve flight-times enormously. Every gram of weight counts in. Also, always use tewing gum or glue on your nuts and bolts to make shure nothing falls of because of vibration, as you can see one of my legs almost fell of during a flight.
Never trust a quadcopter. No redundancy on the propellers means complete chaos if you loose a prop, or a motor defects in mid-air. Always expect your copter to crash in the only little river when it has about 2square miles of open field to crash-land in. Remember to mark your copter with etched/milled imprint with your phone-number and name if you do get a fly-away or a crash far away.
Always double-check that your Lipo-battery-warning is connected to the battery if you fly without any other battery-sensors or telemetry to monitor your battery-capasity. My lipo-sensor from Dealextreme barely disconnected from the plug in flight once, and i had a voltage drop over a field, with a following rapid decent and smooth crash-landing. Everything survived fine, but if i where to fly over something else (like water or buildings) that would be a catastrophe.
If you want to fly FPV, please consider building a hexacopter for redundancy. A quad is too vulnerable for flying like crazy with a video link.
Always buy double up of deal extreme motors or escs, 1 out of 4-5 will have some defects. I bought 8 motors, and two of them had some issues.
Mounting a led-strip in a V form on the back two arms of the quad makes it very easy to fly in night time, as it will be one big bright arrow pointing the direction of the plane. Actually it makes it even easier to get the direction of the copter right at night, than in daytime! Definitely recommended if your building your own!
I was already half-finnished designing a smaller version of my quad when the other crashed into the river, and my plan was to move the electronics over to the new one when the old one crashed somewhere. So until i can afford buying new ESCs, DJI m V1, and a less expensive 6 channel spectrum receiver, it has been put on hold. The frame is already built (pictured below) and just waiting for cables and electronics.
This is a video of my cnc machine milling out the aluminum frame for the version 1 of the quadcopter.
Here is the picture gallery of the build, including sketchup renders of the build i made before putting it together. The brushless motor mounts and the mounting of the top rods to the center of the framee is 3d printed, and the legs are cnced out of 4 mm plywood.