Over the years I have developed a procedure for setting up an Electric Aircraft that pretty well assures it will fly right off the board. Others have asked me about this, and here is the procedure that I use
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How do I choose the Motor etc.

I go into Hobby Lobby with the weight of the plane, and look at the AXI Motor (My particular Favorite) and choose a motor designed to fly that weight of plane. In the tables for that motor, you will be given the prop size, batteries required, and the ESC to be used.

Once the plane is fully assembled and setup in my transmitter.

1. Weigh the plane ready to fly.
2. Hook up the Eagletree Data Logger, and the power source.
3. Using a Fish Scale, measure the Pull at full throttle using a harness around the tail feathers. Using this figure and the total weight, you can compute the Thrust to Weight Ratio. Depending on the type of Aircraft, this can be from 70% to over 100%. I like to see at least 90% Thrust to Weight myself.  This also depends on the Aircraft,  my Viking Old Timer for example has only 65% thrust to weight and flies great.
4. Check the RPM if you have a Tach, or the Eagletree RPM sensor.
5. Tie the plane down, and run the motor at half throttle, with 10 seconds of full throttle ever minute. Checking the battery and motor for heating during the entire process. If it is the proper setup, they both may get warm, but not overheat. Run until it goes into cutoff, or you can see that the motor is sagging.
6. Take the Eagle tree to computer and check the graph. Look at the Amps, voltage curve, and Cumulative MAH etc. Using these values, you can determine if the power setup is going to work for you. Maybe a different prop is needed, or higher MAH batteries etc.
7. Using the timeline from the data logger, I set the times on my transmitter to insure not running out of battery in flight. I normally set it for 3-4 minutes less than the cutoff time for throttle time, and 2-3 minutes less for the total time. This pretty much insures that I will seldom get into trouble due to a total loss of power when landing. Plus it helps the batteries last longer.

Prior to the Eagletree Data logger, I was able to get most of this data and manually compute the information using my Astro Wattmeter. It as well will give you the AMPS, Volts etc. Enough to make the computations to see if you have the power setup right.

I have created a Database program in MS Access that allows me to input all the data obtained above, and it will do calculations to give the total picture. Over time I have collected enough data in the database, that I can usually go back to a previous setup, and use it with any new plane I build. This helps determine everything much quicker.

Click here to Download the Database - Requires Microsoft Access