leading edge radius

[bearsa]

is there an optimum leading edge rad for out right speed and does this varie for an aerobatic plane

[Andy W]

The leading edge of the wing is merely the forward-most part of the airfoil. There is no 'correct' radius, it is the shape designed into the airfoil, which varies for any of the multitude of airfoils out there. In general, however, faster models tend to have thinner airfoils, and as a result, the leading edge is 'sharper' or has a smaller radius.
..a

[Sparky Paul]

"outright speed" and "aerobatics" are somewhat mutually exclusive flight domains.
Skinny wing for the forner, fat wings for the latter.
Bluntish leading edges and slow(er) speeds keep the airflow attached longer when manuvering.

[DaveSawers]

A sharp leading edge stalls easier and may be of use for an aerobatic model.