Specifications

nel 3) and connect the brushless motor ESC to channel 5 on the receiver.
30.7.2. Adding a heading hold gyro to a brushed 3-in-1 controller
You can add a heading hold gyro to a brushed 3-in-1 controller by using a heading hold gyro
(without remote gain), and a tail ESC. You will need to rewire the electronics as follows:
1. The throttle channel will go to the 3-in-1 board, and the main motor will still be controlled
by the 3-in-1 board.
2. The rudder channel will now go to the heading hold gyro, and the tail motor ESC will plug
into the heading hold gyro.
Basically, you will only use the 3-in-1 board as a main motor ESC, and all other functions will
be handled by the other components.
30.7.3. Brushed tail motor to brushless conversion
If you are using a brushed 3-in-1 controller, then you can use a PowerZone board to convert
the brushed tail motor output into a servo signal, then you can plug a brushless motor control-
ler into the PowerZone board.
Otherwise, if you are already using separates, then just replace the brushed tail motor ESC
with a brushless tail motor ESC.
If you are using a heading hold gyro and you replace a brushed tail motor with a brushless tail
motor, then the tail will probably wag very badly because the brushless tail motor will generate
more thrust than the brushed tail motor.
If this occurs, you will need to trim the tail rotor to reduce the tail rotor thrust. You should trim
the tips of the tail rotor instead of the trailing edge of the tail rotor, because this will create a
more efficient tail rotor (smaller rotor with more pitch is more efficient at generating static thrust
than a larger rotor with less pitch).
Be sure to trim the tail rotor in small steps and test the tail rotor thrust by flying the heli to en-
sure you do not trim too much from the tail rotor.
30.8. Battery info
30.8.1. Battery terminology primer
LiPo batteries are usually described as something like "5S2P 4200 maH 10C". This can be a
bit confusing to understand.
30.8.2. Battery pack series/parallel rating
The xSxP parameter descdribes describes the arrangement of cells in the battery pack.
The "5S2P 4200 maH" means there are 5 batteries in series, with 2 sets of these in parallel for
a total of 10 cells. The capacity of the entire pack is 4200 maH and there are two sets of bat-
teries in parallel, so the capacity of each individual cell is 2100 maH.
Alternatively, you can think of the battery pack as each cell is doubled up in parallel, then 5 of
these doubled cells are connected in series. Either way, the pack will behave identically.
Technical Appendix
207