Open Loop: the open loop configuration means no additional position feedback on the stage and the location is kept by knowing where home is and the controller keeping track of the motor steps. KOHZU’s standard offering is 5-phase motors thus the chance for losing steps is very unlikely.
Rotary Encoder: this position feedback is an encoder mounted to the output shaft of the motor which is coupled to the ball screw or ground lead screw driving the stage. These are for applications where linear accuracy are less critical but wanting feedback for the controller. It is important to understand that a rotary encoder cannot compensate for any potential backlash in the system.
Linear Encoder: when the highest level of accuracy is mandatory, the use of a linear encoder is prudent. The linear encoder is mounted to the table (moving portion of the stage). This mounting configuration allows the controller to compensate for any backlash in the system. Keep in mind for this discussion, the term “linear” is a generic term. These encoders can be mounted on most KOHZU stages including the linear, rotary and swivel/goniometers. These mounting configurations measure the displacement of the table even in rotation thus allowing the controller to convert to a rotational move.