D ^ Driver That portion of the electronic package that receives the stepping sequence from the translator and provides the switching of the windings in the stepper motor. R ^ Ramping The process of controlling the pulse frequency to accelerate or decelerate a stepper motor. Ramping increases the ability to drive larger loads at greater speeds by slowing the first series of pulses allowing the motor to overcome inertial loads and reduces overshooting by slowing the motor down more gradually than an unramped motor. S ^ Step Angle The angular increment the motor shaft will turn each time the windings (coils) are energized. The angle is specified in degrees. For a 200 step per revolution motor the step angle will be 1.8 degrees. Step per revolution The total number of steps to rotate the motor shaft 360 degrees. For CNC, 200 or 400 steps per revolution are usually used. Stepper motor Adevice that translates electrical pulses into precise mechanical movement. The output shaft may deliver rotary or linear motion. T ^ Translator An electronic device that converts pulses into the correct switching sequence which will operate the motor one step for each pulse received. U ^ Unipolar A bifilar wound motor. The current flows only in one direction through each winding. Normally there are two winding per bobbin and eight bobbins per motor. Usually is a 5, 6 or eight wire motor. One or more common leads are used per winding. Has less torque than a bipolar stepper motor but is simpler to drive. Bipolar stepper motor- just two windings. The electronic controls reverse the current alternately between the coils. This motor has more torque but requires more electronic controls. X ^ X Axis An axis that is left or right. All movement left of a zero point is minus (-X), all movement right of the zero point is plus (+X). Y ^ Y axis An axis that is at right angles to the X axis and intersect the zero point of the X axis. All movement further away from the zero point is plus (+Y). All movement closer than the zero point is minus (-Y). Z ^ Z axis An axis that is vertically perpendicular to the X-Y zero point. All movement above the zero point is positive (+Z) while all movement below the zero point is (-Z).