Intro: DIY Quadcopter From Scratch
Flying is something that has been part of man's wish forever. We have wanted to take to the sky ever since we first saw a bird fly and with the advent of technology we can travel by air across the world. However a personal flight experience is something unique and the closes we have come to a personal flying vehicle is an RC aircraft.
RC hobby has taken the world by storm and with electronics getting cheaper, getting into the hobby is easier than ever. A quadcopter is something that can take flight, hold it's position in air and you have do a lot with one. However the bigger they become, the more expensive it gets and in this tutorial I highlight the step I took to create my own quadcopter.
I made the frame from scrap wood, got the motors, props, RC transmitter/receiver and flightcontroller from ebay and put everything together at my convenience. This is my first quad and prolly not my last and I hope you can get something out of my experience.
Step 1: Making the Frame
The first thing to do is make the frame. In my case I started with scrap wood board which was 24mm thick. First we cut up two lengths which are 30mm thick and 2 feet long. From one of the two lengths, we cut off a 30mm length from a 2feet arm so that we may form the required structure.
Using the three pieces we form the X and to hold it in place, I used a rectangular piece of wooden sheet (2mmthick) 60mm x 150mm with nails and glue. Let the glue dry for a few hours depending on the type of glue.
Step 2: Getting the Motors and Props
Depending upon the size of the quad, we need motors, props and Electronic Speed Controllers. In my case, I have used EMAX MT2213 935kv Motors and 10inch props from ebay. For the speed control, I bought the EMAX 4in1 esc which has 4 ESCs in one.
Step 3: Mounting the Motors
Depending on what kind of motors you purchased, this step will vary a bit. I used a vernier calliper to measure the distance between the mounting screw holes on the motors and drilled holes accordingly.
I also drilled a hole to allow the shaft and clip of the motor to move freely. This is applicable for these kind of motors and if your motors came with mountings then you may skip this part.
Finally I used appropriate screws to secure the motors in place.
Step 4: Mounting the ESC
Once the motors are mounted, I connected the ESC on the bottom side and I used zip ties to fix everything. I will be hanging the battery under the quad as well but the ESC is tied down and secured.
Step 5: The Landing Gear
For the landing gear, I cut 20mm thick pieces of 6inch diameter pipe. I have four pieces that are essentially rings and used duct tape to fix them there. They are not only cheap but also help in absorbing the shock when the quadcopter lands.
Step 6: Choosing a Flight Controller
In order to control the quadcopter and make the whole thing stable in air, we need to have an electronic system that can take care of everything. This computer is called the flight controller and we need to either make one or buy one. There are a number of open source flight controller projects out there and the more popular names are as follows.
1. ArduPilot I have followed this project for some number of years and it started as a shield for an arduino which was called an ‘oil pan’ and later was upgraded to bigger hardware and is currently one of the most expensive hardware for RC airframes. The GUI is great and the performance is great as well. It has automated flight modes etc but to a beginner its just too much.
2. DJI NAZA I have read good things about this one and the full featured version is called the DJI NAZA M V2 which is a costlier than the Ardupilot, is closed source but is the absolute best at what it does. Bucket load of features for a bucket load of money. There is also a DJI Naza Lite which is much cheaper but again closed source.
3. OpenPilot CC3D The best open source hardware I have read about is the CC3D which is based on an STM32 based chip and has the MPU6000 and 6 channels. Its open source and you can install your own firmware on this one like base flight and clean flight(more on this later). It was originally a kickstarter project but is now available from a number of sources. I recently bought one of these and I have to say its the EASIEST to setup as the software has a wizard to guide you through all the steps the first time around. You can mess with the advanced controls later.
4. NAZE32 The NAZE32 is the next best thing to the CC3D and is a bit more flexible BUT its a bit more difficult to setup as opposed to the CC3D. Its used by advanced fliers who have control over the controls and want their quads to do more tricks.
5. KK2.1 This is one of the first boards you will find online when you search for quadcopter controllers. It has an LCD which allows you to set it up without a PC and is based on the AVR controllers. It used the MPU6050 as a sensor and you may write your own firmware for it but you will need a AVR ISP programmer since it does not have one on board. Its cheap but requires manual tuning and is better for the more advanced flier.
6. KKMulticontroller Yes! its different… well almost. Its based on the Atmel AVR (168p) as well but I think the support for this one has been discontinued. Their website kkmulicopter com is gone and I think the makers have moved to making 32bit flightcontrollers or something. Its a bit outdated and used Murata Gyros only for measuring the orientation. No sensor fusion and the gyros themselves are analog and you have trims to set the offsets. Pretty neat but highly outdated.
I chose the OpenPilot CC3D due to it's simple configuration.
Step 7: Choosing a RC Tx Rx
In order to control the quadcopter in the air without wires, we need a wireless remote control system. There are number of option from Futaba, Spektrum etc which are very expensive and some other like Turnigy and FlySky that are cheaper.
The number of channels on the remote means the amount of control signals that you individually send to the aircraft. We need at least 4 channels for
In addition to these we may need channels for any camera control later. Hence I chose the flysky 6 channel which is cheap but not recommended for long range flying. Pick one according to your budget
Step 8: Mounting the Flight Controller
Before we calibrate the quadcopter, we need to fix everything. I mounted the flight controller on the top with the heading arrow in the X direction. It was fixed using zip ties the same as the ESC on the bottom. One major difference is the addition of a piece of sponge under the Flight Controller. This allows to absorb vibrations from the motors.
Step 9: Connecting the OpenPilot
We need to connect and configure the Flight controller to our ESC as well as to the Remote control. I have not been able to upload a video of my own due to bandwidth restriction at my end so I found a tutorial video which is quite good and to the point.
Additionally, there is a video on how to configure the Flysky remote and if you have a different remote, you will need to make the necessary changes accordingly.
Step 10: Testing Everything
Before we take flight, we need to verify using the OpenPilot GCS that everything is working right. GCS has a display to test the sensors etc. Take off the propellors and test with your remote to verify that everything works well.
I also tested the range by placing the quad at a location and moving away to a significant distance. The props make enough noise when ON to let you know that they are working well.
Step 11: Finally: Taking Flight
The quad is a dangerous machine and cause serious damage if not careful. Connect the battery and place the quad on the ground in an open place. From a safe distance, arm the flight controller and slowly throttle up. If you feel its trying to drift in a direction, use the trims to make the necessary correction. Once its stable, experiment and learn how the quad responds to the various inputs. You can tweak the various PID values till you get the desired response from the quad.
Congratulations you just built your own quadcopter from scratch! Be safe!