With curved blades the freehand grinding technique can follow the edge due to our highly developed hand-eye coordination. In the factory a grinding fixture is used for curved blades which has a carbide "finger" set vertically at the axis of the wheel, on the outer radius. It is pointed and just clears the grind stone. The blade is fitted to a movable table or sleeve and the wheel is lowered to achieve the desired cutting edge. The blade is run over the finger and maintains a constant set. Expensive wheels are used like the pink Bradley wheel or the white Nortons. Beautiful results are achieved. But satisfactory results can be acheived with the H-Frt 10" pedestal grinder (or equivalent) and the common grey wheel. (with practice) :drink: