While developing my driver for the Electronic Speed Controllers (ESC’s) for my quadrocopter (see “Kinetis Drone: Driving the Electronic Speed Controllers“), I noticed a some strange smell, followed by a failure of one motor ESC 😦
The four ESC’s are all in a rather tight compartment under the quadrocopter. And one of the ESC’s started producing heat, and did not drive the motor any more. The ESC’s are protected in heat shrink tubing to isolate and protect them.
Opening it did not show any obvious problem on the top side:
The problem is on the bottom side:
One of the motor wires of the Graupner S3055 ESC has been placed over the edge of one of the motor drivers. These drivers can get rather hot, and with the shrink-wrap and probably some pressure/vibration it was enough to ‘melt’ the cable isolation enough the reduce the isolation enough that it created some shortcut, melting away even some of the solder :-(. Interestingly, the wire isolation only seems to be ‘melted’ half way through, but that was enough to reduce the isolation enough.
I will see if I can repair the ESC, or if I have to order a new one. In any case, it will take some time to have all motors spinning again. I think it is really a bad design to have the wires going over the motor drivers. I think I will open up the remaining ESC’s and make sure that the wires are not going over the motor drivers. And I’m always learning from failure :-).
Happy Smoking 🙂