Milling and turning are daily operations in CNC machining workshops. Both technologies use cutting tools to remove material from solid blocks to make 3D parts. Material removal is a method of classifying them as a subtractive manufacturing process, but there are key differences in these operations.
Turning means that the workpiece rotates around the central axis. The cutting tool remains stationary and moves into and out of the workpiece for cutting. Turning is used to create cylindrical parts and cylindrical derivatives; for example, think of parts shaped like baseball bats, shafts, railings, and uprights.
The chuck holds the workpiece in the center of the rotating spindle. The base is fixed with a cutting tool so that it can move along the axis of the workpiece and enter and exit radially. Feed and speed depend on the rotation speed of the part, the radial cutting depth and the speed of the tool moving along the workpiece axis.
Turning operations include OD and ID cutting and grooving, boring, chamfering and drilling. Since the cutting tool applies force to the workpiece in a direction perpendicular to the axis of the workpiece, it is important to support the workpiece to reduce deflection.
On the other hand, in the milling operation, the cutting tool rotates, and at the same time firmly fixes the workpiece to the table.
The cutting tool or worktable can be moved orthogonally in the X, Y, or Z directions for cutting. Milling can produce more complex shapes than turning. It can even produce cylindrical shapes, but in order to save costs, it is best to leave these shapes to the lathe.
In CNC milling part machines, the chuck holds the tool in a rotating spindle. The tool is moved relative to the workpiece to create a pattern on the surface of the workpiece. The feed rate and speed are calculated based on the rotation rate of the cutting tool, the diameter and cutting edge number of the cutting tool, the cutting depth, and the rate at which the cutting tool moves on the part.
The limitation of milling involves whether the tool can enter the cutting surface. Using longer and thinner tools can improve the operating range, but these tools may be skewed, resulting in poor machining tolerances, poor surface finish, and more tool wear. Some advanced milling machines have articulated joints that can perform angle cutting and improve operability.
Both turning and milling operations can be used to create complex parts. The main difference is the shape of the final part. For cylindrical parts, please turn. For most other parts, milling works best.
Post time: Feb-11-2021
