fickfräsning

Fickfräsning, or pocket milling, is a milling operation used to create pockets or cavities in a workpiece by removing material with rotating cutting tools. It is common in metalworking and woodworking and is performed on milling machines, including CNC milling centers. The goal is to produce a defined cavity with flat or contoured bottoms and straight walls, suitable for hardware, weight reduction, or assembly clearances.

The process begins with fixturing and tool selection. A CAM-generated toolpath is used to clear material from the pocket through one or more passes. Common strategies include roughing passes that remove the majority of material with relatively large stepovers and depths, followed by finishing passes with smaller stepover to improve surface quality. Pocketing paths may follow the pocket boundary, spiral patterns from the edges toward the center, or a zigzag pattern, depending on machine capabilities and geometry.

Tools and parameters: Pocketing typically uses end mills or ball-nose mills. The choice depends on pocket size, wall geometry, and bottom finish. Key parameters include step-down (depth per pass), stepover (lateral advance), and cut direction (climb versus conventional milling). In wood, chip removal and vibration are important considerations; in metal, coolant and chip evacuation are important for productivity and surface finish.

Applications and considerations: Fickfräsning is used for creating housings for electronics, pockets for fasteners, weight-reducing cavities, or decorative or functional features. Limitations include tool deflection, chatter, and the need for rigid fixturing and good chip removal to maintain dimensional accuracy and surface quality.