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--Chapter VII-- VII、Face Milling Z-Level Milling overview Z-Level Milling geometry Z-Level Milling Operation Parameters Z-Level Milling Cutting Parameters Z-level Milling Example Mechanical Engineering@XiHua University

To be able to Create a ZLevel Milling. Chapter VII To understand the Z-Level milling. To understand Steep Containment. Objectives To be able to Create a ZLevel Milling.

7.1 Z-Level Milling Overview 7.1.1 What’s Z-Level milling Use Z-Level Milling for fixed- axis semi-finishing and finishing. Z-Level Milling maintains a near constant scallop height and chip load on steep walls and can be especially effective for high speed machining. Z-Level Milling

7.1 Z-Level Milling Overview With Z-Level Milling, you can do the following: Profile the entire part, or specify Steep Containment so that only areas with a steepness greater than the specified angle are profiled. Cut multiple levels in one operation. Cut multiple features (regions) in one operation. Cut by level for thin-walled parts. Maintain the tool in constant contact with the material.

7.1 Z-Level Milling Overview 7.1.2 Advantage to use Z-Level milling Z-Level Milling has the following advantages for semi-finishing and finishing: Advantages Zlevel does not require blank geometry. Zlevel has steep containment. When cutting depth first, Zlevel orders by shape, where Cavity Milling orders by region. On closed shapes, Zlevel can move from level to level by ramping directly on the part, to create a helical-like path. On open shapes, Zlevel can cut in alternating directions, creating a zig-zag motion down a wall.

7.1 Z-Level Milling Overview 7.1.3 Z-Level Milling operation Subtypes Tab.7-1 Z-Level Milling operation subtypes

7.2 Z-Level Milling Geometry Tab.7-2 Valid geometry for Z-Level Milling

7.3 Z-Level Milling Operation Parameters Steep Angle The steepness of the part at any given point is defined by the angle between the tool axis and the normal of the face. When specifying Steep Containment, only areas with a steepness greater than the specified angle are profiled. Option Description Steep Containment Restricting the cut area based on the steepness of the part Merge Distance Connecting the end points of cutting moves that are less than the specified distance apart to eliminate unwanted tool retracts . Minimum Cut Length Eliminating tool path segments shorter than the specified value.

7.4 Z-Level Milling Cutting Parameters 7.4.2 Between Levels Between Levels is available for Z-level Milling only. It allows users to cut all levels without lifting back up to the clearance plane. Use Transfer Method Direct on Part Ramp on Part Stagger Ramp on Part

7.4 Z-Level Milling Cutting Parameters 7.4.3 Cut Between Levels Cut Between Levels option is used to create extra cuts when there is a gap between the cut levels in Z-level machining, which eliminates the large scallops in shallow regions left from standard level-to-level machining and eliminates the need to create a separate area milling operation for non-steep areas, or to use a very small depth of cut to control scallops in non-steep areas. It can minimizes excessive tool wear or even breakage from rapidly loading and unloading the tool in areas that have large scallops left behind from previous operations, producing a more uniform stock for semi-finishing and a more consistent surface finish with fewer retracts and engages for finishing.

7.4 Z-Level Milling Cutting Parameters 7.4.3 Cut Between Levels Cut Between Levels off Cut Between Levels on Notice the shallow regions have large gaps Notice it produces a more uniform cut path and eliminates large gaps between cut levels.

7.4 Z-Level Milling Cutting Parameters 7.4.5 Reference Tool  Reference Tool is used to eliminate tool motion where there is no material. It references a larger tool from a previous operation. The smaller tool in the current operation removes the remaining material in the uncut regions where the larger reference tool could not fit. Overlap Distance: Extends the width of the area to machine for the specified distance along the tangent surfaces of the remaining material. (a) Overlap Distance set to zero (b) Overlap Distance set to a value of 15.00

7.5 Z-Level Milling Example Z-Level Milling Part Model Tool Path of Z-level Milling with Direct on Part Option Tool Path of Z-level Milling with User Defined Cutting Levels

THANKS 封志明/机械工程学院 2019年5月19日