In order to pick out a motor and esc combination, you really need to know the weight of everything you are putting in the air. You already have the battery, so weigh that. Weight the servos, receiver, fuselage with the wing and tail, everything. Then go to a vendor's web page and get the weight of the motor and esc you would like to use and add it all up.

Read through the following and work it out.

Once done, you will know what wattage you are working with and what motor and esc to buy. Always go to the higher level when figuring out what motor and esc to buy.. if it works out to 17 amp ESC, go to a 20 amp ESC. Match the motor to the esc. If it doesn't match up with what you picked out, move to a motor/esc combination that does, get the weight (should not be that much difference) and work it out again and get the right one.

You should be fine.

Here are some guidelines:

1. Power can be measured in watts. For example: 1 horsepower = 746 watts

2. You determine watts by multiplying ‘volts’ times ‘amps’. Example: 10 volts x 10 amps = 100 watts

Volts x Amps = Watts

Therefore,

Amps = Watts / Volts ( / = divided by ). Simple elementary math.


3. You can determine the power requirements of a model based on the ‘Input Watts Per Pound’ guidelines found below, using the flying weight of the model (with battery):

50-70 watts per pound; Minimum level of power for decent performance, good for lightly loaded slow flyer and park flyer models
70-90 watts per pound; Trainer and slow flying scale models
90-110 watts per pound; Sport aerobatic and fast flying scale models
110-130 watts per pound; Advanced aerobatic and high-speed models
130-150 watts per pound; Lightly loaded 3D models and ducted fans
150-200+ watts per pound; Unlimited performance 3D and aerobatic models

4. Determine the Input Watts Per Pound required to achieve the desired level of performance:

Example:

Model: E-flite Brio 10 ARF
Estimated Flying Weight w/Battery: 2.1 lbs
Desired Level of Performance: 150-200+ watts per pound; Unlimited performance 3D and aerobatics
2.1 lbs x 150 watts per pound = 315 Input Watts of total power (minimum) required to achieve the desired performance

5. Determine a suitable motor based on the model’s power requirements. In this case, you will need a motor/esc/battery combination for 30 amps continuous... 3 cell LiPo at 11.1 volts (nominal) is 315/11.1=28.xxx amps, round out to the higher 30 amps.

So, get your paper and pencil out and work out the details. Let us know if we can help.



CGr