We have received reports of a small number ESCs failing in the field. After reviewing the failed units and their setups, we believe that we have found the cause. On certain applications, we have discovered that plugging the motor’s timing wires directly into the ESC can lead to a failure.
This can be caused by two factors:
One, the motor’s timing wires are inflexible and usually less than 3 inches in length. This makes it difficult to plug the motor’s male bullets into the ESCs female connectors. This can lead to damaging/bending the male connector, which in turn results in a loose and poor connection. As a result, this loose connection can potentially disconnect during use which can cause an immediate and catastrophic failure of the ESC.
The second potential issue is due to vibrations. Because the motor’s timing wires are stiff they have no slack or relief. Due to the extreme nature of some setups, the vibrations and the motor’s movement from torque can stress the female bullet connectors installed on the board and lead to a failure.
Castle highly recommends using 2 – 3 inches of appropriately sized silicone wire. The silicone wire (like the battery wires on the ESC) is quite flexible and provides some strain relief to the bullet connectors.
Below are two images from Helifreak user, “rotary guy” and a Talon 90 installed in a Goblin 500 helicopter. Note the extra lengths of wire between the connections and how this provides some post-installation flexibility, reducing the amount of “wire pulling” during flight while still maintaining a neat and tidy installation.