Is there a difference between air and surface servos?

[BrianG]

The only thing I can think of is the gearset, despite being metal, maybe isn't as durable as surface-specific servos? Electrically-speaking, servos operate on the same pulse stream scheme (not like air vs surface ESCs).

[Overdriven]

Originally Posted by BrianG

The only thing I can think of is the gearset, despite being metal, maybe isn't as durable as surface-specific servos?

That was always my understanding of it. The gearset not being able to withstand the shockloads a land vehicle would see in say the steering system. Aircraft servos see loads that are more steady (or ramp up more slowly) instead of shock loads (like hitting a rock while driving). I'd imagine the gearsets for land based vehicles are wider to better deal with shock loads.

I think the nicd thing is just a holdover from the old days. Most planes were almost always 4.8v when nitro and gas was king. Keep the input voltage within the servos limits and everything will be ok either way.