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70" Extra 300 EXP V2

 - 1778mm (70") Wing Span
 - 1778mm (70") Length
 - 65.4 sq. decimeter Wing Area
 - ±5080 grams Flying Weight
 - 30cc Class

Out-of-Box and Build Comments

Review :

What a beautifully built plane this is!      March, 2020

Positives:
    - Very nice Oracover film finish - not a bit of additional shrinking required.
    - I like the cowl attachment method - actually fairly typical of planes this size.
    - Very well glued up airframe - nice and solid. The veneer of carbon fibre allows for a very light airframe that is quite strong.
    - The undercarriage mounting is very sturdy! - Very nice carbon undercarriage.
    - I like the wheel stub axles. Did however replace the foam wheels with Dubro low bounce that fitted into the spats.
    - Very nice canopy slide clips. They did require a bit of trimming and lubrication to get them to slide well. 
    - Ball jointed push rods are great.
    - Rolls Royce tail wheel assembly!
    - Robart round hinges used for all control surfaces - very nice.

    - Wing Bags provided with the plane - NICE. There's even a slot for the SFGs which I remove in order to pack away the wings in the bags. 

    - Lastly, the oracover finish design is beautiful....

Negatives:
    - Well, ... not a one!


Out-of-Box:

- Very sturdy packaging.

- All components nicely held and protected in place by bubble wrap, plastic bags and tape. 


Build:

- A spinner from my stock was sprayed a matching orange. Nice aluminium back and spins very square with no wobble.

- The undercarriage structural support is well considered and very tough.

- I took a long time to install all the hinged control surfaces, making sure they are nicely located and quite free of glue mess etc.

- In general, the build went very well. Rudder nice and square to the wings. The rear stabiliser required minimal shimming to get it parallel with the wings. I certainly like the innovative EF method for building the stabilizer in one piece.

- I employed  a center-located servo for the rudder (with comensurate pull-pull operation). 

- All servos fitted with EF push/pull arms.

- The motor mount is a proprietary EF standoff. Looks very nice.

- I like the air scoops for cooling the motor more effectively.

- Installed an arming switch (XT90 version) and 20 amp regulator. The regulator is connected to just one of the batteries and is armed when the arming switch is inserted.

Current (2020, March),
Successful Flying Setup

Power Considerations:

    - Using the 2 x 5S 5000 50C batteries, EF Xpwr 30cc motor and 19x12 APC prop was supposed to yield about 2180watts at the ESC. This equates to a theoretical 455w/kg just past the 450w/kg considered a minimum requirement for an aerobatic plane. Certainly, the plane has plenty of get up and go!

    - After a full 5 minute sequence, the plane lands with all cool components - nice.

    - The sound of the plane with this power system is very pleasing. Really quiet and powerful.

Comments after about 10 flights:

    - Even at high power the plane produces very low noise - pleasingly quiet in flight. I like calling it "quiet authority".

    - The very soft, "low bounce" Dubro wheels are very quiet even on the rough grass strip! The grease and snug tight wheel collars (no play along the shaft) contribute to this quiet performance. 

Overall Performance:

    - Altogether a very nice performing plane. I am well pleased. The Aura-8 may require some fiddling on the computer but it surely makes for a very smooth flight.

    - I have added the provided SFGs (Side Force Generators) and the roll performance is great with better knife edge boyancy. The SFGs must be checked for parallel installation to avoid left to right oscillation during flight.

    - Super plane, top marks to Extreme Flight.

Installed Equipment

Propellor

Manufacturer: APC
Size: 19x12 E

Spinner

76mm Spinner, with aluminium back, sprayed to match the aircraft orange.

Motor

Manuf.: Extreme Flight
Model: Xpwr 30cc
RPM/V: 214kv
Max Power: 3,000W
Shaft Diameter: 8mm
Weight: 536g

Motor Controller (ESC)

Manuf.: Turnigy
Model: RotorStar 
Rating: High Voltage, 80A
BEC: No! Opto.
Functionally the same as the equivalent YEP. Employs the YEP ESC-setting card.

Rx Power Regulator (SBEC)

Manuf.: YEP
Rating: 20A
High Voltage input allowed with variabl, to 8v, output.

All Servos

Manufacturer: Hitec
Size: HS-5495BH 
High Voltage with Karbonite gears.

Battery

Manufacturer: HRB
Size: 5S 5000mah 50C
Good quality batteries used as 2 x 5S in series. Very low internal resistance, <4mohms per cell.

Flight Control System - Stabiliser

Manuf.: Potenza
Model: Aura-8
Apart from initial Quick Setup and Quick Trim adjustments, all adjustments have to be made using a computer connected to the Aura-8. A bit of a pain. No useful flight control settings are maintained in the transmitter!!
Not withstanding all this, the stabiliser works very well.

Satelite Receivers

Manuf.: Spektrum
Model: DSMX Satelite
Two of these plug into the A and B ports on the Aura-8.