A low-cost machine for grinding the flutes in twist drills requires two axis of movement. One moves the drill forwards underneath the grinding wheel, the other rotates the drill to produce the helical flute. At the end of the cut, the rotary axes has to index the drill round by 180 degrees to be ready to grind the second flute. The linear speed of the workpiece does not exceed 0.5 inches/sec.

Machine Objectives:

• Two-axis control
• Low cost
• Easy set-up and change over of part programs
• Smooth, accurate cutting motion

Motion Control Requirements:

• Two-axis control
• Linear interpolation between axes
• Nonvolatile program storage
• Flexible data pad input
• Moderate Speed
• Programmable I/O

Application Solution:

This is a natural application for stepper motors, since the speeds are moderate and the solution must be minimum-cost. The grinding process requires that the two axes move at accurately related speeds, so the controller must be capable of performing linear interpolation. The small dynamic position error of the stepper system ensures that the two axes will track accurately at all speeds.

Product Solutions:

• Controller - 6K
• Driver - ZETA4-240
• Motor - RS42C
• Operator Interface - RP240