When using the CNC rotary table on a Sherline mill, the stepper motor mount will normally overhang the edge of the table. The fact that the bottom of the stepper motor mount is a little below the bottom surface of the rotary table is of no consequence. However, when mounting the CNC rotary table on a large mill table or other flat fixture, the bottom of the stepper motor mount will keep the table from seating flat on the surface. This 1/2" thick plate raises the rotary table an amount sufficient that there will be no interference problem between the stepper motor or mount and the surface of the table.