RE: Walkera #4 Fixed Pitch Helicopter Forum
The Walkera 4 uses a single 4410 transistor, which can handle 8A when they get hot. (Up to 71 degrees C)
These can easily drop off at higher loads, say, 10 amps continuous, and there is no airflow across them.
Solder it back on, then perhaps add a heatsink and some fins, held in by the case with the fins protruding into the airflow.
That should solve that problem.
Also check to see if the motor is binding. Mine barely gets hot, and I've just come in from a 10 minute + hover for the first time...
It was only warm after that.... But if the motor is too tight, it will take more current, and heat the driver a lot more.
Does yours take off and hover just barely under center stick?
David