grant-RCU

My Feedback: (10)

I just bought a gws edp 50xc motor and prop combo. On 7.2 volts it makes 2.10 ounces of thrust and draws 1.66 amps of current. weight .53 ounces, A gws ics 50 speed controller weight .15 ounce
I also bought a E- Tech 7.4 volt 450 mah Li Poly battery weight .87 ounces.


The plane is made from pink foam like blue core and a stick of lattice cut down thin.

Wing is 14 inches X 6 inches H stab is 18% v stab 9%. 1 inch ailerons and 1 inch elevator. 2 hs 55 servos and a gws pico 4 channel rx.

AUW with 2 servos, push rods and horns and the rx a whopping 1.8 ounces
AUW total should be 3.36 ounces. Now i should be able to get 450/1660 * 60 16 mins of flight time at full throttle!

I am a tad concerned about the thrust to weight ratio. 2.1 ounces of thrust to 3.36 to 4 ounces of plane weight. How much variation can it be between the two?
The wing loading is around 6 ounces per sq inch it is in the good range for the Reynolds numbers as well around 7 on the 6 to 9 scale. 6 being a floater 9 getting on the heavy side.

Matt Kirsch

My Feedback: (21)

Thrust only has to overcome drag in order to accelerate the plane forward. The weight of the plane is irrelevant.

Actually, your thrust to weight ratio is quite good. A plane will fly with as little as 1:4 for thrust:weight ratio. I wouldn't worry about it.

grant-RCU

My Feedback: (10)

I was thinking if you scaled this up and had a engine producing 5lbs of thrust and a plane weight 10 lbs. Doesnt seem like it would fly.
At 4 ounces the wing loading will be 6.86 and the cubic wing loading 8.97. if it comes out a tad lighter like i expect it will be 5.76 and 7.5.

humm so my 2.1 ounce thrust motor could fly a 8 ounce plane if the wing loading was low enough.