RE: When do I need to use a voltage regulator?
I had installed the Futaba Gy401 Gyro and S9254 servo on a newly built heli. The battery I built for it was a five-cell 6.0 v and I had only been flying the heli for a second week when the rudder servo stopped working in flight. Just prior to turning off power to the heli, the servo began smoking violently. I found out that the S9254 does not handle 6.0v, but the gyro does. Expensive lesson. I now use the regulator with all planes and helis when utilizing 6.0v packs.