Hi Justin,

OK, expo - -

Forgetting the effects of geometry for a second, normally the control surface will move a given amount for a given amount of transmitter stick movement.

That's the set up you have now.

But it's a good idea to have less sensitivity in the middle of the stick movement than at the extremes. This would mean that very accurate adjustments could be made to the control surface around their straight and level flight positions, but when sensitivity wasn't needed, at the extreme of the movement, it is still available.

Exponential movement allows this to happen by taking the linear nature of the movement and dipping the curve so that the further you are away from the centre, the greater the effect of moving the sticks.

Negative exponential (in Hitec, but it may be different in other radios) will reduce the sensitivity in the centre, whereas positive exponential will increase the sensitivity in the centre (used sometimes in the rotor control of a helicopter)

Incidentally, see here :-

http://www.hitecrcd.com/Support/Manu...pse7Manual.pdf

for the Hitec manual that explains it far better than I could!

You will need Adobe to read that, but if you haven't, come back to me here and I will email you the manual.

Hope that helped!

-David C.