DM-9CNC Wheel Dressing Machine Download Brochure

For position feedback, other CNC dressers often employ rotary encoders. In such a setup, the servomotor shaft position is reported by the encoder, and this plus the pitch of the motion screw is used to calculate slide position. Even with a precision ballscrew, there is error between this calculated position and the actual slide position -- especially during direction changes -- due to backlash, friction, compliance, etc. As the mechanics wear, the position error gets progressively worse. Dressing a circular contour with only rotary feedback is a nightmare, since doing so  requires coordinated motion with multiple direction changes. The DM-9CNC uses linear encoders attached directly to the slide, ensuring accurate positioning under all conditions so the resulting contour is always true to form.