The Relative plunge attribute in 3D machining affects how the Plunge clearance attribute is used.
When Relative plunge is deselected, the tool plunges to the Plunge clearance as an absolute value. This can cause the tool to feed an unnecessary amount for parts that are not flat. For example, in this uphill only surface toolpath the tool rapids to a set Z value and then feeds to the part on each end:
When Relative plunge is selected, Plunge clearance is used as a relative distance from the surface. For example, here the tool plunges down closer to the part.
