The Difference between Electric Spindle and Mechanical Spindle
The electric spindle is usually used in CNC machinery, while the mechanical spindle is used in general machine tools.
The electric spindle integrates the machine tool spindle and the spindle motor. The belt drive and gear drive were eliminated from the high-speed numerically-controlled machine's main drive system. The machine spindle is driven directly by the built-in motor so the length of main drive chain is zero.
The mechanical spindle is used in the machine tool that drives the workpiece or the cutter to rotate. It is composed of spindle, bearing and transmission parts (gear or belt pulley).