MAG IAS has introduced new W/Z zero tracking capability for its horizontal boring mills and HMCs with the Siemens 840D control. Previously available only on the NumeriPath 8000 control, W/Z zero tracking for up to three collinear axes can be retrofitted to existing MAG machines with 840D controls or added to new machines. W/Z tracking accounts for changes in machine geometry when one of the axes in a collinear set is repositioned in the part program. It is designed to electronically track each axis of the collinear set to calculate and maintain the correct part reference coordinate when one of the axes is repositioned. For example, the Z-axis reference point is typically the spindle gage line, while the W-axis reference point is a surface on the workpiece. After the W/Z relationship is established through part referencing, the control tracks all Z and W axis moves, displays their relationship, and moves one of the two axes to maintain the correct gap position.