Why would you want to build a UAV? Well, first, what is a UAV? A UAV is anything that flys and doesn't have a pilot or someone directly controlling the aircraft. I bet you have heard about the CIA drones, well those drones are a type of UAV. Now, why you would want to build one. WHY NOT?! I mean, having your own plane that can fly itself based on waypoints....that's pretty awesome. Plus, we're going to do the whole thing for less than $400. Yes, you read that right. That's everything; plane, controller, RC connection and camera downlink. EVERYTHING.
So, if I have convinced you, let's start with the parts.
Oh, and please vote for this project! :) Every vote helps a lot.
Step 1: Parts - RC plane
This is going to be a long list, so just bare with me. These are the parts that you are going to need to just build the plane. If you aren't interested in making it autonomous (fly itself) this is still a pretty awesome plane. OK, here goes:
Fuselage - http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXFRU7&P=ML
***It seems as if this fuselage has been discontinued. You can by the RTF version here: http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXFXV0&P=ML and change out the motor.
****There is also a substitute frame that you can buy here: http://www.hobbyking.com/hobbyking/store/__16544__Hobbyking_Bixler_EPO_1400mm_ARF_.html
If you buy this plane, then you don't need to buy a motor or servos. It comes included.
Magnets - http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=8288
CA accelerator - http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=8456
CA glue - http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=8443
Hinges - http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=8424
Propellors - http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=8006
Carbon Fiber (x2) - http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXJDN9
Carbon Fiber (x2) - http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXJDP4
Foam sheeting...you can find it at your local hobby + crafts shop
ESC - http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=2165
Servos - http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=662
Motor (doesn't have to be this one, but something close) -http://www.hobbyking.com/hobbyking/store/__15190__S2858_2630_Brushless_Inrunner_2630kv_.html
Battery - http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?id
Charger - http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=7028
Power supply for charger: http://www.hobbyking.com/hobbyking/store/__20968__Hobbyking_60w_Power_Supply.html
Safety charger pack - http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=4134
XT60 connector - http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=9572
Battery monitor - http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=14627
Insane RC controller - http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=8992
Y harness - http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXSGN3
Step 2: Parts - UAV
So, this list isn't fully finalized. I'm still working on the best controlled for the UAV system that isn't to expensive and still gives the user enough flexibility in programming the system. So, this part of the project is still in progress and will be updated as I find new systems. Below are some of the pieces that I'm experimenting with.
Step 3: Lay out the parts
Ok, you have a ton of parts. Let's go over everything once again and what each part does/will do. The photos below will tell you what each part is...this is a good step to refer back to for more information on parts.
ESC - controller for the brushless motor.
Brushless motors - Ok, here's a crash course in a sensorless brushless motor. Brushless motors are better for a few reasons, they are more energy efficient and more controllable than brushled motors, hence why we use it on a long duration flying UAV. First, how a brushed motor works: it has a stator on the outside which consists of magnets and a rotor on the inside that has a coil of wire. When you run electricity through the coil, it creates a magnetic field which pushes against the stator spinning the rotor 180 degrees. Once it has spun 180 degrees the coil is now atracted to both sides of the rotor and doesn't want to spin. So, we flip the voltage in the coil flipping the magnetic field and spinning the rotor 180 degrees. In a brushed motor, the spinning rotor flips the magnetic field mechanicaly by use of brushes. In a brushless motor, the magnets are spinning, so we can't flip the magnetic field mechanically. Hence why we need a brushless controller, the controller pulses the magnetic field correctly to spin the motor.
Brushless motor rating - This is the little complex part. There are a few ways to rate brushless motors, but the most important for us is the kV value and the amps that it draws. the kV rating tells you the sed that the motors turns depending ont he voltages. The amps that the motors draws in pretty self explainatory... To find how long the plane is going to fly, take the maH of your battery and divide by the the amount of amps your motor wil draw (that will give you a rough estimat of duration-of-flight).
Servos - These aren't just great for RC planes but for anything robotics. Servos are a great way to get presice motion. There are three wires, black is negetive voltage, red is positive voltage and yellow/brown/orange is the signal wire. The signal is a pulse sent from the receiver that tells the servo what position to go to.
RC - Radio Control. Pretty self explanatory. We have a transmitter (the thing with joysticks) and the receiver (the little box that goes inside of the plane). I personally have a 9 channel transmitter, but you will only need a 5 channel transmitter (4 for flying the plane, and one shutoff channel for the autopilot).
Step 4: Cut out holding areas
Cutting out the holding areas is hard. What you want to do is cut out the bottom of the plane as close to flush with the inside wall ans you can. You can measure with a ruler to make sure that your cutting the right amount...I just used a piece of cardboard :). Once you have cut out either side of the hatch from the fusalage, you are going to want to glue the two halves together. Make sure that you remember which side goes where....you want the hatch to fit snuggly when the plane is flying.
Step 5: Layout carbon spars
Now it's time to layout the carbon spars to support the frame. I used 5 different types, 3 small tubes in the front of the plane and two large one running along the bottom of the plane. Here's how I installed them:
For the front of the plane:
There is one center spar and two spars on the outside. For the spars on the outside, I just stabbed the carbon spar into the foam and pushed it in as far as possible. For the middle spar, I tapped it in place then ran an exacto knife along the edge of the carbon spar. I then pushed the carbon spar into the goove and glued it in place using CA glue and then spraying it with CA accelerator.
For bottom of plane:
This is harder...You want to cut grooves the same size as your carbon spars along the inside edge of the plane. In other words, you want the spar to run along the inside (interior side) of the fusalage. I installed them to run along the edge of the cuts that we made for extra storage (look at the last picture below). Again, you want to glue these in place by putting CA glue in the foam cut and spraying the spar with CA accelerator.
Step 6: Cut out spaces for wires
Pretty self explanatory. You are going to want to be able to run power and control wires to the holding bins from the main compartment to both of the extra compartments that you have made. I've also added slots for the Y-channel to exit the fuselage and connect to the wings for the ailerons.
Also make a slot on either side of the back of the cockpit (first picture) You want these slots to be pretty wide, but they don't need to be that deep. You will be running the power and signal cables to the ESC.
**Ignore the magnet stuff in the picture. That's for the next step, just ignore them**
Step 7: Insert magnets and handle
Now to get everything together. Kinda. To keep the hatches in place, we're going to use square magnets. I cut out the space for the magnets in the hatch (the area that we cut out before). Use at least three magnets on each hatch (two on one side, one on the other). Once you glue the magnets into the hatch, snap a magnet on and then mark and glue that magnet into the fuselage.
Now move on to the next picture.
We now have to glue magnets into the main cabin cover. Do the same thing as before, glue the magnets into the main cabin cover then snap magnets on and mark and glue those magnets into the fuselage.
Lastly, we want to create a handle for the hatch to the extra compartments. To do so, I use a bent paper clip and some tape, but you can use really anything.
Step 8: Install motor
Install the motor as per the instructions in the manual that came with the easy star. Sorry...nothing special about this step, but I can give some help. Spray the motor with the CA accelerator. Then put beads of CA glue on the RAISED pieces of foam. Drop the motor in with the wires at the top of the plane (look at pictures) and make sure that it is sticking out a little bit (written in the Easy Star Manual).
Step 9: Glue sides together
Again, pretty self explanatory. Put CA accelerator on one side and CA glue on the other side. Stick the two sides together and clamp + rubber band. Make sure to watch the motor, it wont want to stay in place. I used a clamp (as per the picture) to hold the fuselage together around the motor.
Oh, and contrary to the manual, run the wires of the motor out through the ventilation hole (look at picture below).
Step 10: Solder connectors
Fire up that soldering iron (to 360F to be exact)! You don't need to follow these steps exactly, but they are just helpful suggestions. We will be first working with the 3 red wires that come out of one side of the ESC.
1. Put ball of solder on the motor wire
2. Hold down gold connector somehow....I use a pair of second hands
3. Stick wire with ball of solder into the gold connector (look at first picture to see which side, there's a finished one in the background).
4. Then solder! You might want to put in a little extra solder once it if in place...you don't want this to fall out.
Now for the battery connector:
1. Grab a XT60 connector (in picture below)
2. Take the red and black wire coming out of the ESC and solder them in place according to the pictures (make sure that the wires are correct!)
Step 11: Modify + install stabilizers
Time to cut a larger rudder This is crucial to make sure that you have control of your plane. Cut two pieces from the foam close to matching the pictures below. Make sure to cut an "up angle" so that the vertical stabilizer can still go up and down (you can't test this...you will later). Cut off the rudder from the plane. Make a slot in the vertical stabilizer to put in the hinges (one at the top, one at the bottom). Glue the hinge in place on the top and the bottom. Take one side of the foam cutout and glue it on one side of the protruding hinges. Then glue the other side onto the first side (so you have the foam sandwiching the hinge).
Ok, now install the elevator (as per the instructions). Install the servo horn in the elevator as per instructions. Install the servo horn into the rudder by making a slot for the bottom of the "T" of the plastic (look at picture). Then put CA accelerator on the foam, CA glue on the plastic horn, and shove in into place. Make sure that the holes are facing the front of the plane.
Step 12: Install ESC
First, put electrical tape around the gold connectors to make sure that nothing shorts. Then, plug the ESC into the receiver (I can't explain how to do this, it's going to be different for each receiver). Turn on the controller and plug the battery into the ESC. Plug the motor wires into the ESC gold connectors...there isn't a specific order, just plug 'em in. Install a prop onto the motor. Turn up the throttle. If the plane moves forward, your all set. If it moves backward mess with the motor wires (the three wires) until it goes forward. Then tape everything in place and run the power (red + black) and signal )the 3 wires together) down into the cockpit through the groove we made. Put a piece of tape over the wires.
Step 13: Install servos
Plug servo into a port on the receiver with the ESC and battery plugged in. Install servo horn to be facing the right direction (the two servos should be mirror images). Unplug everything. Rap servo with electrical tape to protect the gears from glue + other stuff. Next, install the plastic sheaves and wire to connect the servo to the horn on the rudder + vertical stabilizer. Slide the "Z" part into the servo horn, spray the servo with CA accelerator, spread CA glue on the foam and glue in place.
Step 14: Build the wingOk, for this I'm just going to say build the wind like the instructions in the Easy Star Manual. I know that we have the Y channels for ailerons, but I don't have good pictures for the mod. I'm re-doing the mod for my dad and will add that to this instructable soon.
Tip: spray paint the wings a bright color. Not only will this make the plane look awesome, but it will help you see it while flying.
Step 15: Install battery safety lights
Very important step...this makes sure that you don't crash because of low battery. Run the lights to areas that face a little downward in the front and back of the plane. Glue everything in place. Make sure that the end can run to the cockpit to connect to our flight battery.
Step 16: Install flight electronics
This is going to be a little different for each person. The battery should be velcro-ed into the bottom of the plane. The receiver can really go anywhere...I installed it right above the battery in the very nose of the cockpit.
****Make sure that when you install the battery you check the CG of the plane*** To check the CG, put the wings on and balance the plane on your finger right on the back edge of the foam piece that you installed into he wing (feel for the seam). Move the battery backward and forward to make sure that the plane is balanced. If you ever install more electronics into the holding bins, make sure that you recheck and fix the CG.