
Electric Setup Guide
ATTENTION: For detailed information on a given edf size motor, click on either the 50-70mm Set Up Guide or the 90-120mm Set Up Guide link. Charts will be present that will give more information on the motors that we carry.
There are many combinations and set ups that will work for electric powered aircraft. Here are some formulas that will make it easy for you to determine what the proper set up will be for a jet.
Take the voltage of the battery and multiply the KV of the motor = Fan RPM 11.1v X 3600= 39,960 rpm.
Take the desired fan RPM divide it by the battery voltage = Needed Motor KV 45,000/ 14.8v=3040kv motor.
Take desired fan RPM divide it by the motor kv = Battery Size 45,000/ 3600kv=12.5v (3 cell).
Take watts divide it by the volts = Amps 800 watts/ 14.8v=54amps.
Take watts divide it by the amps = volts 450 watts/ 40amps= 11.25volts.
Take amps multiply it by volts = Watts 57amps X 14.8v= 843watts.
These are approximate numbers depending on efficiency, quality of connections, and resistance, but this guideline will help determine what setup to use with electrics. The data below are estimations based on the above formulas and information provided by the manufacturer. Fan Jets USA is not responsible for changes in the specifications of the motors by the manufacturer.
The following are recommended setups for edf units based on fan rpms. The higher the fan rpm, the faster the jet. Please note that 50-70mm fans are rated up to 50,000 rpm. Anything above this may exceed the manufacturer's recommendations. The 90mm edf's are designed to operate from 30,000 to 47,000 rpm. Speeds vary based on the weight and aerodynamics of the jet. The 120mm edf units are designed to operate around 24,000 to 38,000 rpm.
Be sure to use a watt meter when programming the power system to check the watt and amp draw. This can be limited by adjusting the throttle epa's. Going up in blade count will have an impact on the watt and amp draw. Generally, a lower kv motor should be used on edf's that have higher blade counts.
For more information on how electric power works in r.c. aircraft click on the following articles: