Changes
/* Beginner guide/links/building */
* https://youtu.be/gRSPFYlKo58 How to build Retracts for Quadcopters/multirotors
* http://www.tjinguytech.com/charging-how-tos/parallel-charging Chargin two batteries pack
=== Failsafe with d4r-ii ===
* It's very very important to set the failsafe of the d4r-ii correctly
* By default it'll retain the last value of all channels, thus contuying on its course
* Procedure:
** Bind the receiver (bind mode on tx, turn on rx with the button pressed, turn off everything)
** turn on the rx only, press the button once
== Calculators ==
