Abstract: An indicator for indicating displacement of a controller displaceable about an axis angled to vertical direction: the indicator comprising an epicyclical gear comprising a sun gear, a planetary gear and an annular gear; the sun gear being coaxial with the annular gear; the annular gear being asymmetrically weighted to be self rightening by gravity; the sun gear being fixable to the controller and serving as a driving gear; the planetary gear being driven around the inside of the annular gear by the sun gear, wherein a centre of the planetary gear serves as a pointer and a reference indication is fixed to the annular gear such that relative position of pointer with respect to reference indication indicates displacement of the controller about its axis.