Basically,  is a rectangular plane base with a CNC mechanism on it  (ball-screw, two guides, cart and four linear bearings); the CNC simple mechanism is, actually, replacing an expensive actuator; on sides there are two triangular rods sistem needed for lateral stability of leg. The CNC mechanism is driven by a step-by-step DC motor, witch is driven by an MCU. This MCU is a PIC648 wich send to stepper impulses for STEP & DIR, using a simple stepper driver with L298 and diodes...