Hi guys,

Possibly dumb question: What makes a 'surface' servo unsuitable for air? For example, the Spektrum 6040? It's described as a surface servo, but the specs sound good for jet use. Why not?

TIA

Mounting height and size are usually the big difference

Hi,

Thanks, Len. Nothing else, though? There's not like some little chip in there that senses altitude and then self-destructs the servo because it's supposed to stay on the ground?

LOL. I've wondered the same thing myself. Conversely, there are stickers on some servos that say "aircraft use only".
Go figure.

A friend who used to work in a hobby shop said it refers to the length of the lead.

I bought a pair of 'surface' Futaba analog servos to drive flaps (high torque, reasonable price)
and the leads are shorter than what I would expect.

The instructions do warn about using 'ni-cd batteries only' perhaps because some people would
use dry cell batteries in their cars which could not provide the current to drive these servos properly
but I checked the current draw & it was nothing too outrageous.

John.

Sean I've used those servos for years. A little slower response and less precise otherwise fine.