I centered my router to the plate I just made out of 1/2 flexiglass. I located the center of my plate then drilled a small hole, layed my router with center bit on it and everything was measured from the center hole. I included the center insert came from Rocker by routing the depth of insert and drilled a 3" hole. The insert accommodate the PC bushing. Also I included 8 leveling set screws seating on magnets