ORIGINAL: helibutt
Is there a technical reason for the torque-shaft not being available for an electric version ?
Why is a torque tube considered "a step up" from a belt tail?
Answer to first question is "price increase".
Electric motors have enough torque to rip the teeth off the main gears, so a lack of torque is not even possible.
Answer to second question is " torque tube gives you an extra minute of flight time from the same input power" and less heat too.
reason is " shaft drive has less parasitic drag than a belt does".
Harry [8D]