My Project - Sparrowhawk M5 (EP)

Specification:
Full Size plane: M5 Sparrowhawk
Original Design: Graham Reddin
Type : RC Electric Airplane
Electric Motor: AXI 2820-10 Brushless
Speed Control: Emax 60A ESC w/BEC 
Battery: LiPo - 3s 3300mAh
Servo: 4 x HS-81 Servos
Material: Balsa, some plywood for reinforcement and foam for wing core

Made from balsa in 2007, i started the project by plot the CAD file of M5-Sparrowhawk model aircraft on A0 paper size. Construction steps provided by the designer was really helpful with some detail photos on important part of the aircraft.

The plan which already plot before transferred to balsa sheet using thin thinner and brush. Once the inked outlined the balsa sheet, its ready to be cut using hobby knife / paper blade.

Start cutting the side skin and former part first then apply thin CA to form a fuselage. Follows by cutting and glued both horizontal and vertical stabilizer include rudder and the elevator as well.

Wing are made from foam core (cut using hot wire method with airfoil template) sheeted with balsa using odorless CA to prevent attacking the foam.

 

The three part (right, left and center part) of sheeted foam wing core shall be joined together with dihedral angle at joint line. I using fiberglass thin fiberglass cloth and long cure epoxy to bond it all together. This construction stage also being utilized to fitting the aileron servo and all wire inside the wing.

"Pre-commissioning" stage I like to say it, it's time to check the airframe alignment, weight-balance, control linkage movement and the functionality of the electronics parts.

Since the first flight, my M5 already gone trough several color scheme, from dark navy blue with white strips, light blue - orange and the latest one the pylon race scheme - sand brown.

The flight performance using mentioned setup give relatively short take off despite the take off weight which approximately 1.5 kg. For low wing type of model aircraft, tip stall eventually appeared as speed decreased. Therefore landing approach shall be made by approx 1/4 throttle and cut off only when it reach about 30cm above the runway.

I broke the landing gear several times especially when the there is a crosswind during landing. Improvement for landing gear bracing and shock absorber arrangement are strongly suggested.

*(original design by Graham Reddin - http://www.rcgroups.com/forums/showthread.php?t=160067)