Open Loop CNC Drive Systems

It is characterized by no feedback system in the drive system. MCU gives control to the drive motors. This is being assumed by the system that the machine table shall reach the target position. There is no way from the MCU to identify the real performance of the system. Given figure shows a block diagram of an open loop CNC drive system.

                                                                                       Figure: Open loop CNC Drive system

Usually PTP system uses open loop drive systems, where cutting tool doesn't engage with workpiece throughout positioning. They might also be utilized in light-loaded cutting machines. Though they are economical but are vulnerable to load resistances throughout positioning.