Introduction to CNC Turning(cnc laser cutting machine for metal Louise)
- source:ESKRIDGE CNC Machining
How CNC Turning Works
CNC turning centers utilize two axes of motion - the X and Z axes. The workpiece is held and rotated on the C axis, providing the third axis of motion. The cutting tool is mounted on a tool turret and can move in two directions. The X-axis controls the infeed of the tool perpendicular to the rotation axis of the part. The Z-axis controls the position of the tool along the rotation axis. By precisely controlling the movement of the tool along these axes, material can be removed to create turned features like diameters, grooves, tapers, threads, etc.
The CNC machine follows programmed instructions from CAM software to position the tool and control the cutting parameters. Common instructions include the tool position, spindle speed, feed rate, depth of cut, and more. The use of optimized tool paths and cutting data allows high quality parts to be produced quickly. The closed-loop controls ensure precision by constantly adjusting for variations during machining.
Setup for CNC Turning
CNC turning requires production-ready setup including proper fixturing of the workpiece, tool presetting, and verification of the CNC program. The workpiece must be securely mounted onto a chuck, collet, or fixture on the spindle. Manual setup tasks are minimized by the use of robotic part loading/unloading systems.
Cutting tools need to be preset to accurately establish tool offsets. This is done using an automated tool presetter. CAM software accounts for the tool dimensions and positions so that the programmed coordinates correspond to the required part features.
The CNC code is simulated in CAM before being sent to the machine control. Any issues can be detected and corrected in the digital environment prior to machining the actual part. Doing so avoids machining errors and collisions.
Types of CNC Turning Operations
Different types of turning operations are possible depending on the required part features. Common turning operations include:
- Facing - Machining the face of the part to create a flat reference surface.
- OD Turning - Machining the external diameter of a cylindrical or conical part.
- Boring - Enlarging the internal diameter of holes.
- Grooving/Cut-off - Cutting grooves and parting off finished parts.
- Threading - Producing external and internal threads using thread cutting tools.
- Tapering - Creating linear, convex, or concave tapers.
- Contouring - Following 2D profiles using turning and simultaneous multi-axis interpolation.
- Drilling/Boring - Machining center holes and producing bores.
- Tapping - Producing internal threads by tapping holes.
The operations can be combined in sequence to produce complex turned parts with multiple features. Programming patterns and cycles are used to simplify CNC code for repetitive features like grooves, threads, etc.
CNC Turning Machines
There are several types of CNC turning machines:
- CNC lathes - The most common type designed for general turning applications. Examples are 2-axis lathes, multi-axis turning centers, and multi-tasking lathes.
- CNC screw machines - Used for high production of small, precision parts like fasteners and medical components.
- CNC cylindrical grinders - Machines internal and external diameters to tight tolerances and fine finishes.
- CNC vertical turning - For larger diameter parts. The workpiece is positioned vertically with horizontal tooling.
- CNC multi-spindle lathes - Multiple cutting heads allow simultaneous machining for high-volume production.
The capabilities of the machine impact the complexity of parts that can be produced. Advanced turning centers include live tooling, Y-axis capability, and B-axis milling functions. Twin spindle machines allow simultaneous front and back machining of parts. Bar feeders, gantry loaders, and robotic systems can be integrated for automation.
CNC Turning Applications
CNC turning produces parts across many industries including automotive, aerospace, medical, energy, electronics, and more. Typical applications include:
- Automotive - Engine components like shafts, pulleys, gears, valves, etc. Transmission and drivetrain parts like axles, bearings, couplings.
- Aerospace - Structural aircraft parts, engine components, nozzles, rotors, and fasteners.
- Medical - Implants, surgical instruments, connectors, orthopedic and prosthetic devices.
- Industrial Machinery - Pump housings, hydraulic cylinders, valve bodies, precision shafts and couplings.
- Consumer Products - Household items, sporting goods, computer peripherals, electronics housings.
- Defense - Precision ordnance like shells and casings. Parts for guidance systems and electronics.
The accuracy, repeatability and production rates make CNC turning ideal for these applications. Industries continue to adopt CNC turning to streamline manufacturing processes.
CNC turning is an essential, efficient machining technology. The computer control and optimized tool paths provide precision and speed not achievable with manual turning. Setup is simplified with the use of automated tool presetting and verification with CAM simulation. Different turning operations can produce a range of part features and complex geometries. With continued advancements, CNC turning will take on more critical roles in high-performance applications across manufacturing industries. CNC Milling CNC Machining