RE: Futaba 3154 on 6 volts???
well since he's using it on the tail and not the swash 5v is fine and it's still faster than a 65hb. I think the issue is probably the fact that a tail servo is always working, adjusting to the conditions where a cyclic servo only moves with input. So running it at 6v when it's continously in use is probably what's killing them.