How to Greatly Improve the Efficiency of CNC Finishing

The purpose of finishing is to ensure the final dimensional accuracy and surface quality of the workpiece. To improve the finishing efficiency, it is necessary to consider both the surface quality of finishing and the finishing time. First, analyze the surface quality of finishing, which largely depends on the height of the ridge left after processing.

What is CUSP height?
CUSP height refers to the maximum height of the raised part of the residual material after the cutter passes through two adjacent cutter paths during machining.


How to reduce the height of CUSP?
A feasible method is to reduce the step over, reduce the distance between adjacent toolpaths. But this means increasing the number and density of toolpaths per unit area, that will increase the finishing time.
Better surface = longer machining time.

Another feasible method is to use large tool. Because the larger the tool radius, the larger the arc at the point of contact with material. Under the same tool path density, the obtained CUSP is about small.

10mm ball cutter with 4mm steps
The CUSP: 0.4322mm

25mm ball cutter, the step distance is also set to 4mm
The CUSP: 0.152mm

Two knives of different sizes use the same step distance, and the CUSP are compared.

The CUSP can be reduced by using a tool with a larger arc.