The Black Diamond's Journey Part 02

Previously on the Black Diamond article, the wings are repaired temporary by taping ice cream sticks on the top and bottom surface.

Back to the workshop, the wings are further repaired. The tape skin is stripped and the cracks are filled with epoxy glue. Although the carbon spars in the wing are still intact and straight, ice cream sticks are glued to the top and bottom surface to further strengthen the wing. Finally, the wings are covered back with the tape.

This time, the Black Diamond is tested using a different motor with the specs as follows:

New motor : Emax BL 2220/07, 1200kv

Tested spec from the manufacturer : Using 3S Li-Po @ 8560 rpm / 28A with 10 x 4.7 Prop will produce 1300 g of thrust.

With this new motor spec, more efficient flight is expected. The X bracket motor mount has different holes dimension compared to the previous motor mount; therefore new holes’ positions are required to be prepared to mount this.

Tested Drive system :

•  Brushless motor : Emax BL 2220/07, 1200kv

•  ESC : Turnigy Plush 40A, timing set to low.

•  UBEC : Emax 3A/5V

•  Propeller : Revox 10x7E

•  Servos : 4 x Emax ES08MD Digital, Metal Gear servo (2 Ailerons, 2 Ailevators/Elevons)

•  Li-Po Batt 01 : Turnigy Nano Tech 3S-2200mAh (35C-70C) (Either one is connected)

•  Li-Po Batt 02 : Turnigy 3S-2200mAh (35C-45C) (Either one is connected)

Radio Tx/Rx system:

• Futaba T8FG Super, 2.4 GHz transmitter

• Futaba R6028SB, 8ch 2.4 GHz receiver

Flight review :

• The model feels underpowered for quick maneuvers and vertical climb.

• 80% - 90% throttle for effective flight; caused high heat production and inefficient flight.

• It is recommended to implement the previous setup using Turnigy park 480, 1320kv with 10 x 7E or 9 x 6E Prop.

• Airbrake mixing is implemented to alter the ailevators and ailerons position for take-off (side hand-launch).

• The second battery acts as a counter-weight to simulate FPV gears' weight.

Here is the flight video :

Further flight test of the Black Diamond was conducted with lesser A.U.W setup. One of the Li-Po batt (211g) is traded with a roll of tapes with lesser weight; the roll of tapes was attached to the nose (102 g). The C.O.G was shifted backwards approximately 1.5 cm; causing it a little tail heavy.

Flight review :

• The Airbrake mixing was applied too much upwards angle for the ailerons and elevons; causing it to pitch up at high angle, and then stall occurred. (This occurs during hand launch take-off and at the end of the video)

• The model feels underpowered for quick maneuvers and vertical climb.

• Lesser A.U.W makes 65 - 75% throttle for effective flight.

• It is recommended to implement the previous setup using Turnigy park 480, 1320kv with 10 x 7E or 9 x 6E Prop.

Here is the video of the event:

The journey will continue…

Future updates :

•  Implementing FPV system to the model.

•  Implementing UAV system to the model (autopilot).

The Black Diamond can be assembled with either FPV setups; with GoPro camera or CCD camera. The flight will be conducted soon.

D.L. ENGINEERING - The Sky is Home

www.dle-tech.info

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