If I put carbon fiber tape on the leading edge of the wing, will I need a larger motor to keep the plane in the air?

What if I want to add a servo and a bomb?

If I was using a 400 motor, would I go to a 540? And what about the gearing and prop?

This seems so confusing!!!

Carbon fiber is very light, so unless you put the tape on edge, creating lots of drag, you should not have to increase the power.

As far as the other items go, it will depend on the airplane. If you have lots of power now, the plane flies and climbs well, you can get away with adding a little more weight. Just remember that the plane will not perform as well when the extra weight is added.

The amazing thing about electric motors is that you can get more power by simply using a slightly larger propeller in many cases. Another way is to add another cell to the battery pack. Yet another way is to change the ratio of the gearbox.

Just changing prop size, cell count, and gearing willy-nilly will not work, though. You need to do it intelligently, or you will lose efficiency and/or damage the motor, ESC, and battery.

It's not as simple as swapping in a physically larger motor. If you change nothing else, a bigger motor will often result in your plane having LESS power. You also need to change the propeller, gear ratio, and battery.

The biggest drawback to adding a bigger motor is that it adds weight. Bigger motors often require bigger batteries, which adds even MORE weight. All the added weight needs more power to move it, so you get into a vicious cycle of adding bigger motors and batteries until the plane weighs a ton and flies for 30 seconds...

Suffice it to say, there are many modifications you can make to an existing power system to squeeze more power out of it.

So if I have a 380 geared motor and a 8 x 6.5 prop, what would I need to change to add about 6oz of weight?

I'm assuming with a bigger prop it will fly slower, but have more power, right?

Thanks for your help.

What gear ratio?
How many cells?
How much does the plane weigh now?
How big is the plane?

Your plane may not have a useful payload of 6oz, no matter what motor you put on it. There may simply be more weight than the wing can lift.

Like I said, just putting a bigger prop on it MAY increase the power. MAYBE. Putting a larger prop on the motor may just cause it to burn up. It depends on how it's configured now. Unfortunately, you only provided half the information necessary to make that determination.

Maximum thrust with good speed can be made by a 6V 380 motor on 8 cells with a 3:1 gearbox and a 10x6 propeller. It may very well be that you have to change the motor, but you have to change EVERYTHING. That was my point. Sorry if I confused you.

Wingspan: 42.25 in.
Wing Area: 340 sq. in.
Length: 31.5 in.
Function: rudder, elevator, throttle
Power: 380 motor w/gear drive (included) - I'm not sure of the ratio - it doesn't say anywhere in the instructions.

8 cell battery

not sure of the weight either....It's a Wattage Fokker Eindecker


Thanks again.