I have piloted the first successful flight of my experimental RC plane made from easily obtained parts.
Now I will share my creation so others may experiment with the design themselves.
Finished Product
Video of short successful flight into tree.
Control Demo Video
After crashing a balsa R/C airplane and contemplating the repair time, I decided I could make an entirely new airplane which would be much easier to repair in the event of unplanned ground contact.
There are quite a few resources out there for aspiring R/C builders:
Wing made from one standard 18"x24" 4mm coroplast campaign sign.
Tail attached using a standard 48" dowel, cut in half.
Must work with my existing R/C setup (2 servos, ESC and LiPo Battery)
Having these constraints actually made the project a lot more fun for me and kept it from getting too expensive.
Supplies
Body
One standard 18"x24" 4mm corrugated plastic campaign sign
Two 48" long, 0.21" diameter wooden dowels. (this is just the common size, for this project you only really need two 24" and one 36" dowel) OPTIONAL - Two 48" long carbon fiber tubes instead (much stronger) OPTIONAL - Use arrow shafts, they are between 22 and 30" and you can sometimes find free ones
One small plastic Odwalla bottle
4mm thick square piece of wood to fit in bottom of Odwalla bottle
A bunch of zip ties
Double sided foam tape
Electronics/Control/Prop
ESC (Electronic Speed Controller) (20 Amp)
Electric Motor (1400kv Brushless Outrunner)
Plastic Prop (10x9)
Three metal pushrods w/ threaded ends and clevises (18"x2mm diameter)
Three nylon control horns with screws
Three linkage stoppers (or you can just bend the pushrods into the holes)
Two servo arms
Two servos (Futuba)
Receiver (Futuba)
Transmitter (Futuba)
LiPo Battery (Zippy 2200 30C 3S)
LiPo Charger/Balancer (Thunder AC6)
You will need to figure out how to hook the LiPo, ESC, Motor, Receiver, and Servos together yourself. I soldered old molex connectors to the LiPo and used a lamp power switch.
Overview
CAD diagram showing the main dimensions, structural components of the airplane, and proper orientation of corrugated fluting.
Cut wings and tail from campaign sign (you may be able to use just one sign if you are careful)
Cut two 24" dowels and one 36" dowel
Cut along top flute approx 1.5" back from leading edge of main wings
Bend leading edge up and back
Fasten the main wing together using the 36" dowel and zip ties
Fasten main wing back along centerline using zip ties, possibly adding a thin balsa rectangle for strength
Make elevator and ailerons by cutting wedges out from the sides and making hinges as shown below
Tuck the 24" dowels under the 36" dowel
Fasten 24" dowels to wing and tail using zip ties
Cut a hatch from the Odwalla bottle
Place wood inside bottom of bottle
Fasten motor to wood using 4 screws through outside bottom of bottle, making sure it spins easily (you may need a spacer of some sort, depending on your motor)
Fasten bottle to main wing using zip ties
Screw control horns on to ailerons and elevator
Fasten the top wing elevator servo using zip ties
Fasten the under wing aileron servo using zip ties
Cut pushrods to appropriate sizes and attach clevises
Attach pushrods to servos and control horns
Fasten receiver and ESC using double stick tape/zip ties
Switch main power off, connect all electronics
Push LiPo battery into Odwalla bottle so that it will not come out in flight
Perform prop test in a safe environment so as not to cause damage/injury in event of failure
Calibrate servos
Fly!
Detail of a wire I added across top to keep the wing rigid
Detail of aileron and zip tie
Detail of elevator control horn and clevis
Vertical stabilizers added by cutting notches in tail and fins
Detail of motor mount
Odwalla bottle battery housing
Under wing aileron servo with protective bottle
Under wing aileron servo
Detail of under wing aileron control horn and clevis
Cutting Hinges into Corrugated Plastic
Because of the side to side orientation of the fluting I was able to create ailerons and an elevator without any additional hardware by carefully cutting the plastic along alternating flutes.
Use a knife or scissors to slice down the flutes, it is tricky at first, but goes smoothly once you get the hang of it.
