Calculate The Weight Of The Mini Quadcopter

There really isn't any scope for the forum to conduct experiments to determine any of this. Experimentation is therefore best carried out by the original poster.

Everything else being equal, you get greater lift to power ratio with more rotor area. Force is the rate of change of mass x velocity whereas power is the rate of change of .5 x mass x velocity squared. Larger rotor area means lower downward air velocity creating the same lift.

You may have to reduce your gearing ratio between the motors and fans to make up for the greater torque required.

• The minimum lift has to exceed the weight of the equipment otherwise it won't take off.
• The maximum lift is a function of rate of increase of height, which is itself limited by the speed of sound.
• The maximum rate of increase of height is the power of the motors, multiplied by the motor/fan efficiency, divided by the weight of the equipment.

You mean you do not have a testing rig made up already? Go make it! Put a load cell on the motor setup and see what happens at various speeds.

Those are well-done, and nicely presented by the author in relevant units for modelers.

It is not the motors that provide lift nor the rpm of the motor. What is the pitch and length of the props used.

Lift is determined by the pitch of the blade, and the material used for the prop. What size prop does the motor manufacturer recommend for the motor?

If you don't know, then consult a prop sizing chart and pick an option which offers blade lengths and pitch for the motor.

If you put an oversize prop on an IC engine, the engine will likely stall. No harm done. Put an oversize prop on an electric motor and the motor won't stall, it'll just keep on trying to turn the prop.

The motor will draw more and more current as it tries to keep up with its Kv rating - the number of revolutions per minute it has been designed to turn, per each volt fed into it. With too big a propeller, the motor will just keep working harder and harder to spin the extra load, until something (likely the ESC) overheats and catches fire.

Too small a propeller on an EP motor won't do any damage, but you won't get the required performance for your plane. The motor will draw less current and the plane will likely be seriously under-powered.