Introduction to CNC Turning(is brass and bronze the same Clara)
- source:ESKRIDGE CNC Machining
What is CNC Turning?
CNC turning is a machining process where the cutting tool moves while the workpiece rotates. The turning processes cut away material from the outer diameter of a cylindrical or conical workpiece to create the desired shape and dimensions. CNC refers to computer numerical control, meaning the lathe's movements are controlled by computer instructions programmed into the CNC machine.
On a manual lathe, the operator controls the cutting tools and machine movements by hand. With CNC turning, the operator develops the machining program offline using CAM (computer-aided manufacturing) software. The program contains code telling the CNC machine how to move the tool and workpiece to create the desired part geometry. This automation provides more consistency and precision than manual machining.
Key Components of a CNC Lathe
A CNC lathe contains several essential components:
- Headstock: Holds the workpiece in place and rotates it at a defined speed. The headstock contains a spindle which grips the workpiece as well as a motor to provide rotation.
- Tailstock: Located opposite the headstock, the tailstock supports the end of long workpieces using a center point or chuck.
- Tool turret: Contains multiple cutting tools for automatic tool changes programmed into the CNC code. Tool changers swap tools in and out as needed.
- Tool posts: Holds tool holders containing the cutting tools. The tool posts position the tools at the proper height and angle.
- Coolant systems: Provide coolant to lubricate and remove heat from the cutting area. Coolant prolongs tool life and improves surface finishes.
- CNC control: The brains of the machine, the CNC controller interprets the machining program code and drives the machine components.
- Bed: Provides a rigid frame to locate the headstock, tailstock, and tool posts. High rigidity minimizes vibration and deflection during cutting.
Common CNC Turning Operations
CNC turning utilizes a variety of operations to produce common features on machined parts:
- Facing: Machining the end face of a cylindrical part perpendicular to its axis. Prepares the surface for other operations.
- Turning: Machining the outer diameter of a rotating cylindrical workpiece to a desired dimension and surface finish. The most fundamental CNC turning operation.
- Boring: Enlarging the inner diameter of a hole using a boring bar tool. Produces precise hole size and finish quality.
- Grooving: Cutting grooves or circular cuts into the workpiece surface using a tool shaped like the desired groove profile.
- Threading: Producing external or internal threads using the coordinated movement of the tool with the workpiece rotation.
- Drilling: Machining a hole axially into the face or side of the workpiece using a rotating drill bit.
- Taper turning: Creating conical or tapered shapes by offsetting the tool post from the workpiece centerline.
- Parting/Cutoff: Separating a completed workpiece from the remaining stock using a specially-shaped parting tool.
Benefits of CNC Turning
Compared to manual turning, CNC turning provides significant advantages:
- Increased accuracy and repeatability: CNC automation minimizes human error and inconsistency in machine movements. Parts can be repeatedly produced within microns of tolerance.
- Improved productivity: CNC turning machines work unattended for lights-out production. Cycle times can be optimized through programming. Multiple parts can be machined in sequence.
- Complex geometries: Intricate shapes unachievable manually can be programmed into a CNC turning center. Eccentrics, contours, and asymmetrical forms are possible.
- Quick changeovers: Changing programs and tools on a CNC machine allows different parts to be run in flexible batches. Setup time is minimized.
- Advanced features: CNC controls enable advanced features like thread chasing, repetitive cycles, and synchronized spindle/tool movements.
- Automated in-process metrology: Probing cycles and other in-process inspection checks can provide real-time process control and SPC data collection.
Applications of CNC Turning
CNC turning now dominates the production of rotational parts across many industries:
- Automotive: Engine components, steering/suspension parts, wheels, axles, drive train parts
- Aerospace: Structural aircraft components, engine parts, landing gear, missiles
- Medical: Implants, surgical instruments, dental parts, orthopedic devices
- Oil/gas: Pump components, valves, compressor parts, tooling
- Construction/mining: Bucket teeth, drill bits, shear pins, liners
- Industrial: Gears, cams, shafts, couplings, bushings, rollers
Nearly any application requiring high-volume production of cylindrical metal components utilizes CNC turning for its speed, accuracy, and reliability.
The CNC turning process has revolutionized the manufacturing of rotational parts. Its precision, efficiency, and versatility have made CNC the standard for metalcutting industries producing engineered components. With CNC programming capability, a limitless range of part geometries can be created to tight tolerances. CNC turning will continue as a core manufacturing process enabling critical components across diverse applications. CNC Milling CNC Machining