CNC machining technology has gained dominance in metal forming industry in the recent past as it offers highly accurate and repeatable machining capabilities that go further than those achievable by traditional manual methods. For us to decide on which process is suitable for manufacturing our parts, let’s learn the basics of CNC machining Turning.
What is CNC Turning?
CNC turning is a computerized machinist process used in generating cylindrical parts. It can be referred to as computer numerical control for turning under CNC machining types. In this approach, a rotating workpiece is secured into a lathe while cutting tools are used to eliminate material from the workpiece until its shape and dimensions are achieved.
The process of CNC turning
CNC machine turning uses a CNC turning machine to remove material from rotating workpieces with precision so as to make cylindrical parts accurately.
1. Work piece Setup: At first, mount raw material that typically takes form of cylindrical rods made of either metal or plastic, in the chuck or collet part of lathe machine. It means ensuring the correct alignment during machining on which the piece is mounted and centered.
2. CNC Programming: This involves generating or creating a computer program using Computer-Aided Design (CAD) and Computer-Aided Manufacturing (CAM) software. The program will have specific instructions for the CNC machines including tool path, cutting speed, feed rates among other parameters.
3. Tool Selection: Suitable cutting tools are chosen depending on design requirements and material being cut.They may comprise different inserts, drill bits,boring bars ,threading devices etc.
4. Machining Operations : After setting up the workpiece and loading it into the cnc machine; this starts off the process of turnery .The cnc machine rotates at an output speed set by operator while holding onto one axis before & after it cut into materials removing bits at areas where they overlap.
5.Tool Movements: As it engages with rotating workpiece,the CNC system precisely controls the movements of the cutting tool in multiple axes (commonly X and Z axes for simple turning). Thus, tool removes material and shapes the workpiece as per programmed design.
6. Continuous Machining : CNC turning is a continuous process where the cutting tool moves smoothly along the workpiece to remove materials layer by layer until it gets to its desired shape and dimensions according to requirements.
7.Finishing: To meet target surface finish and dimensional accuracy, several passes may be made using different types of cutters. These are usually used for fine finishing which creates smooth surfaces with tight tolerances.
8.Inspection And Quality Control: Once all machining is done, a finished part is taken out of lathe machine while checking it to meet required specifications and tolerances. It may undergo some adjustments or other treatments if need be
Parts suitable for CNC turning
CNC turning is one of the most common methods of making parts in various industries. Here are answers about CNC turning parts suitable for turning according to their categorizations:
Cylindrical parts
– Shafts: like transmission shafts and drive shafts.
– Bushings: like bearing bushings and bushings.
– Pipes & pipe fittings: like pipe fittings, hydraulic pipes.
– Threaded rods: such as threaded bars and nuts.
Disc-shaped parts
-Nuts : for example screws, bolts.
-Flanges : e.g. bearing housing flanges, flanged discs
-The brake disc, clutch disc.
Ring-shaped parts
-Shaft rings; e.g. reducer shaft rings, coupling shaft rings
-Bearing housing rings
Tapered parts
-Conical like conical sleeves, conical shafts.
-3 taper gears
Bump-shaped parts
– Cams including automotive engine cams, camshafts
Complex shaped parts
– Rotationally symmetrical parts such as propellers or fan blades;
– Free-Form Surfaces—turning in more than two axes is required.
In the manufacturing industry turning is employed extensively because all objects that have any form of rotation symmetry or rotational axial shape are turned on this machine. Turning is a method with many applications and it is highly adaptable to nearly any material group including metals, plastics and composites.
Advantages of CNC Turning
- Precision and Accuracy
The highly precise and most accurate cylindrical parts production can be accomplished through CNC turning. The cutting tools that are computer controlled can achieve tight tolerances and maintain a steady output, guaranteeing that the final products satisfy exact requirements.
- Versatility
CNC turning is applicable to many materials including metals, plastics, as well as some composites. It is thus suitable in making different components used across diverse industries.
- Efficiency and Productivity
Once the CNC program is put in place, it automates much of the machining process. This reduces manual intervention thereby increasing productivity and reducing lead times for parts production.
- Complex Geometries
CNC turning allows for the manufacture of complex geometries such as threads, grooves or contoured surfaces with varying shapes. The capability to create complex shapes therefore opens up new design possibilities for engineers and designers.
- Consistency and Reproducibility
CNC turning ensures uniformity of results over several production runs. Once a reliable CNC program has been set up, it can easily be repeated in order to yield identical parts having same precision levels.
- Cost-Effectiveness
While there may be initial setup costs and programming expenses involved, large-scale CNC turning may prove cost-efficient due to factors like efficiency, low scrap rate and uniform output.
The Differences Between CNC Milling and Turning
CNC milling and turning are separate machining processes for making different kinds of parts. While they are both computer numerical control (CNC) methods, their operations, capabilities and applications differ considerably. These are the main differences between CNC milling and turning:
| Types | CNC turning | CNC milling |
| Workpiece motion | The workpiece rotates while the cutting tool remains stationary. | The workpiece is fixed and the cutting tool moves in several axes. |
| Geometries Produced | Cylindrical or rotationally symmetric parts such as cylinders, cones, and disks. | Complex shapes, pockets, slots, and intricate 3D features. |
| Surface finish | Smoother, more polished finish | High-quality surface finish, but may leave tool marks |
| Tools and Setup | Fewer tools and fast processing | Multiple tools, complex setup, slow time |
| Production Capabilities | Chemical Electrical Mechanical Thermal | Boring Drilling Facing Grooving Knurling Parting |
| Industries | 1.Woodworking 2.Electrical industry 3.Electrical discharge machining 4.Metal removing (in automotive or manufacturing) 5.Material fabrication | 1.Woodworking 2.Electrical industry 3.Electrical discharge machining 4.Metal removing (in automotive or manufacturing) 5.Material fabrication |
Conclusion
In CNC turning, a cutting tool removes material while the workpiece rotates so as to shape it. In sharp contrast with ordinary methods of turning, CNC turning is automated and managed by computer programs to deliver unmatched accuracy time after another.
