Castle Creation Thunderbird 36
 

I have a Thunderbird 36 I installed with a Himax 4200 gear box combo and when I slowly start the motor it will bump backwards befor going the right direction. I am using a Corona dual synth. RX and a Futaba 7 TX.
I have flown it a couple times like this but it worries me some.????

Sounds perfectly normal to me. When starting the sensorless ESC's we use have no idea what the initial rotor position is and so can't know which phase to energize first to start rotation in the desired direction. Once there is movement it can figure it out, or the rotor simply catches which way the phases are cycling and drops into sync.

Nothing to worry about, just looks slightly strange until you get used to it.

Thanks for the quick reply.