Coroplast Ver 4.0 - 150cm/43.5dm2 (called it ver 1.0 wing ) vs 170cm/51dm2 (called it ver 2.0 wing)

During the fly, it feels that the plane has less power than expected. The weight is about 3.7kg (not fill tank), the wing used is 150cm/43.dm2. If we calculate, the figure would be (see figures below). After changing the wing with wing ver 2.0, it changes the plane maneuverability/speed/etc. dramatically. It shows from the calculation below, lesson learned, it is not merely the power but it also depends on the wing load and watts per kg determining how your plane would fly ! ...

In summary:
- Calculate your WCL number and plane characteristics.
- Once you have the WCL, please take a loot at Watts/Kg your power RC plane installed.
Both will determine how your plane will fly beside other things such as control surface, length/width of your wing, location of your CG, and other things...

from http://www.ef-uk.net/data/wcl.htm
With ver 1.0 wing the calculation:

With ver 2.0 wing the calculation:

There are many excellent website to calculate Watts/Power requirements for your own design airplane, some examples:

http://www.motocalc.com/tutorial/
"
...

Determining Power Requirements

Regardless of the motor, battery, and propeller eventually chosen, any airplane needs a certain amount of power to achieve a desired level of performance. One simply cannot get around the laws of physics. Because of this basic fact, a number of "rules of thumb" have been proposed based on a plane's power to weight ratio. For example, it is suggested that a plane have about 40 to 60 Watts of power per pound (88 to 132 W/kg) of aircraft for typical "sport" type flying. More aggressive aerobatic flying requires about 70 to 100 Watts per pound (154 to 220 W/kg).

...

"
http://www.rcgroups.com/forums/showthread.php?t=29480
http://www.rcuniverse.com/magazine/reviews/976/ampd3.pdf

Coroplast Ver 4.0 - size 52 - 91 RC Plane

Coroplast ver 4.0 - size 52 - 91

After making 3 previous coroplast plane and learning from some mistakes, finally the ver.4.0 flies. It was not so powerful plane with 43.5dm2 (wing span 150cm) with ASP 52 2T since the wing load is considered more than scale aeroplane. After making the wing load with 51dm2 (wing span 170cm), it flies awesome and can do aerobatics move.

Another thought, i would like to upgrade the engine to 91 2T size. It seems that JBA 91AR is good for the plane. It will add the weight about 300-400 grams but the plane is still considered between aerobatics and scale plane. With this engine, I would expect having awesome speed and crazy maneuverability.

The specification can be seen below:

AUW : 3.6 – 3.8 Kg
Wing Span : a. 1.5 Meter and 43.5 dm2 for ver.1.0; weight approx 1.1kg.
            b. 1.7 Meter and 51.0 dm2 for ver.2.0; weight approx 1.1kg.
Engine : ASP 52 2T, plan to upgrade to JBA 91AR 2T.
Length: 130cm from the spinner to edge of elevator.
Propeller: see the engine specification below what it can accpet. For ASP 52T, my favorite propeller is 12x5
Servos: - 1 * 12g servo for throttle
            - 3 x 30g (2x mini servos for the wing and 1x for the rudder)
            - 1 x 50g (standard servo for elevator)

Engine specification can be seen below:

Type: ASP S52A II - now

Displacement: 8.477cc 
RPM range: 2,000-18,000(r.p.m)
Output: 1.47/17,500(kw/r.p.m) 
Weight: 475g 
Suitable Prop:11*7-12*6

Type: JBA 91AR - future

Displacement: 14.9cc
Bore (mm): 28.12
Stroke (mm): 24
Output (hp/r.p.m): 2.4/17000
Crankshaft: 5/16 x 24
Weight (oz) : 25.96
Recommended prop size: 13 x 8
Practical range: 2500/10500

I have not got a change to video it but soon I will make one...

Please see the picture below from some views :

Soon I will post the details...

Regards,
DS.