Novice math figures

[TddBrwns]

Ok, looking at the weights of the parts I think I understand what the plane needs to weigh.

I am looking at the Jeti Phasor 15/4, Jeti 30/3P controller, 555 receiver.

Motor 4.8 oz
Controller .7 oz
Receiver .8 oz
Servos 4x(.3oz)= 1.2 oz
Batteries 12 oz +-

So, 19.5 oz. just in hardware.

The listing on this motor indicates for planes up to 56 oz.

Simple math 56 - 19.5 = 36.5 oz.

So I have to find/build a plane that is under 2.25 lbs. Including pushrods, covering, wheels, motor mount, etc.....

Does this sound right?

Some kits talk about flying weight, others just list weight. I assume flying weight on a glow model includes fuel, engine and throttle servo. Can I weigh those and subtract from the overall weight listed?


Thanks,
Todd.

Glanced at the Acro Pro and it is listed as a weight of 38 oz. This is the setup listed for this plane. So I assume these are approximate figures?

[Ollie]

Your math is correct. The lighter the airframe, the better the plane will fly. Any more weight than absolutely necessary will degrade the rate of climb.

[Dick Huang]

TddBrwns,
In the past before Electrics were available, we would take a kit and weigh the whole box and it would come close to the flying weight of the model i.e. including the engine, fuel, radio and everything.
Dick Huang