With scales, the best way to achieve eveness is playing them stacatto. First loud, then soft.
This will seem obvious and maybe it is, but...........To play scales evenly, your hand cannot move evenly. The notes must be equidistant in time, but your hand does not move the same distance for each note. Some note changes require the hand to shift rapidly, while others don't. Read Bernhard's Pearly Scales thread again.