Hi everyone. I was asked to built a quadcopter for educational purposes under 450 dollars. Requirements are having follow me,guided,stabilize, loiter modes etc. low cost, durable, easy to maintain and using an open source platform for development purposes. This is not the best quad configuration but it gets the job done. Hope it will give some idea about such projects.
Step 1: Parts List
You can easily find the parts shown belown on hobbyking, ebay, aliexpres sites. Total cost is around 410 bucks.
1. Z600-V3 with crab landing gear Quadcopter frame
2. Crius AIOP v2 flight controller
3.Turnigy Plush 30A ESC
4.E-max 980kv motors
5.Plastic project housing
6.11.1v 3S HRB 5000mah 50C Li-po Battery
7.XT-60 and T-type connectors
8.U-blox neo7m gps
10.Flysky FS TH9X radio set(TX-RX)
11.I-max B6C li-po charger/balancer
12. Double sided copper plate
13.Zip ties and plastic standoffs
14.Power leds and a led driver
15. 433Mhz telemetry module (will be added)
18. 4mm connectors
Step 2: Firmwares (Setup and Configuration)
In order to load the code to the flight controller you need to download the source code and arduino ide. also you will need mission planner ground control station program for setup and configuration and u-center program for gps setup.
Source code version: arducopter-mpng 3.0.1 r4
Arduino version: arducopter-arduino 1.0.3
Mission planner version:1.3.34
Here are some links for further information
1.http://copter.ardupilot.com/ (you can find everything you'll need)
Note: Dont forget to read the readme file in mpng source code file.
After downloading source code from github (DOWNLOAD as ZIP section) find the pde icon inside the mpng file. copy and change the pde file with the pde icon in the lib directory in arduino. Copy all library files to .../libraries/arduino directory. Now open the arduino and go to preferences add the directory folder of mpng code. select HAL board megapirateNG set the programmer to Arduino as ISP and select the board atmega 2560. you are done.
Now open the code from sketchbook and open the config.h tab. For source code configuration, all info is included on megapirateng link.
After loading the code open the mission planner and press connect at 115200 baud. For initial setup and configuration you can click on the first link. Calibrate magetometer,accelerometer,radio etc.
Step 3: Frame Assembly
This is a simple procedure. Take the all four arms and line as quad shape on mounting plate and tighten screws just a little bit. after aligning all arms tighten the screws completely. Then attach the gps mount on the bottom plate. (Red arms and gps stand indicates front of the quad) I used a project box in order to protect the flight controller which has sensitive components. I cut the bottom section of the box for esc wires and the top section for both esc and radio wires and connectors. I also cut front part for gps connector and led indicator. I added plastic standoffs and aligned them to place the flight controller according to the center of gravity. Finally I glued an open cell foam inside the top cover. (Note this frame survived after two 10meters fall)
Step 4: Radio Setup
Connect the transmitter to the flight controller. press menu button select system. select acro mode and pcm signal type. enter the settings menu and set flight modes for aux channel switches set trims, reverse throttle if necessary. You can see the channel inputs from display tab on the radio screen.
In mission planner you can see the initial setup tab and mandatory hardware tab. press the radio calibration button. and move the all sticks and switches.
Since mission planner uses ch5 for flight modes, skip the ch5 of TX (dont connect to ch5 of flight controller) and connect the ch6 of the TX to the FC and connect the ch7-ch8 in order. For channel assignment there is a helpful link below.
Flight modes assignment
Step 5: Motors
These are cheap chinese made motors but still capable of a hover at a 50% throttle. heat up the connectors then melt soldering wire in the connectors. finally dip the stripped wire inside the connector. Dont forget to slide heatshrink tube on the wire before soldering.
Max thrust:880g at 10x4.7 props (I used 10x4.5 props)
3520/2=1760g (which is 200g more than the total weight)
Step 6: ESC Connections
Turnigy plush series are good quality ESCs. We have simple soldering step similar to motors section in this case I soldered t-type connectors to other tip of the esc for easy replacement in case of failures. In order to program ESCs this link will help. Dont attach them to the frame untill the motor directions are set correctly.
Step 7: Power Distribution Board
By using two sided pcb you can do your custom power distribution board.Check for correct connections; one side is positive other side is negative. I soldered t-type connectors and main xt-60 connector for battery. I also soldered additional wires for power leds. Pull the wires. Make sure solder joints are strong. I soldered led driver and 3w power leds in series. they draw about 315mA. I mounted boards to the main frame. I used 3 pieces of standoffs in order to break instantly in stall situations. This will reduce the amount of impact forces those transmitted to the main frame.
Step 8: GPS Setup
You will need an FTDI driver for this setup. Remove the pins from the molex connector. attach the ftdi driver to tx-rx-+5v and gnd(tx of the gps goes to rx of the ftdi module). Open the u-center. select the baud rate for gps and click connect. Select GNSS configuration from the tools tab. Open the u-blox GPS library from the source code directory. find the gps config text and click the file to GPS button. 3D fix occurs in 30-50 seconds. Hdop valu has to be lower than 2 for accurate gps lock. Gps tx-rx pins are connected to flight controller tx2-rx2 pins.(mentioned in readme file)
Step 9: Result
After all kind of settings the quad flies smoothly in stabilize mode. I didnt expect that because of low quality components. After few tries in some modes quad goes out of control that I couldnt find the reason. If I didnt have a small budget I would definetely go for a stronger motor and a better flight controller. In night time its fun to fly around. Power leds make people to think its an UFO :)
Flight time: 10-12 minutes
Takeoff weight: about1500grams