Roughing strategies (adaptive, pocket) in CNC Programming

Introduction

Roughing strategies help remove large amounts of material quickly and safely before finishing the part.

When you need to remove most of the metal from a block before fine details.

When you want to save time by cutting efficiently without stressing the tool.

When the shape is complex and needs careful tool paths to avoid crashes.

When preparing a part for finishing passes that require smooth surfaces.

Syntax

CNC Programming

ROUGHING_STRATEGY(strategy_type, parameters)

# strategy_type: 'adaptive' or 'pocket'
# parameters: dictionary with keys like 'stepover', 'stepdown', 'feedrate', 'tool_diameter'

Adaptive roughing uses smart paths to keep the tool load steady and avoid sharp turns.

Pocket roughing clears out inside areas by moving in layers or spirals.

Examples

This sets an adaptive roughing path with half the tool diameter as stepover and 2 mm stepdown.

CNC Programming

ROUGHING_STRATEGY('adaptive', {'stepover': 0.5, 'stepdown': 2, 'feedrate': 1000, 'tool_diameter': 10})

This sets a pocket roughing path for clearing inside areas with smaller stepdown.

CNC Programming

ROUGHING_STRATEGY('pocket', {'stepover': 0.4, 'stepdown': 1.5, 'feedrate': 800, 'tool_diameter': 8})

Sample Program

This program shows how to set up and start an adaptive roughing operation with a 10 mm tool.

CNC Programming

# Example CNC program snippet for adaptive roughing

TOOL 10 ; Select 10 mm tool
SPINDLE ON 12000 ; Start spindle at 12000 RPM

; Adaptive roughing parameters
STEP_OVER = 5 ; mm
STEP_DOWN = 2 ; mm
FEED_RATE = 1000 ; mm/min

; Start adaptive roughing
G1 Z5 F500 ; Move tool above part
G1 Z0 F300 ; Lower tool to surface

; Roughing passes
G1 X0 Y0 F1000
; ... (complex adaptive path commands here) ...

G1 Z5 F500 ; Retract tool
SPINDLE OFF
M30 ; End program

Important Notes

Adaptive roughing keeps the tool cutting evenly to avoid tool wear and breakage.

Pocket roughing is good for clearing inside areas but may leave corners for finishing.

Always check tool paths in simulation before running on the machine.

Summary

Roughing strategies remove most material fast and prepare for finishing.

Adaptive roughing uses smart paths to keep tool load steady.

Pocket roughing clears inside areas layer by layer.