What is CNC Turning?(cnc machine for automotive industry Leo)
- source:ESKRIDGE CNC Machining
How Does CNC Turning Work?
CNC turning utilizes programmable machine tools called CNC lathes. Like conventional lathes, CNC lathes have a headstock, carriage, and cutting tool. The workpiece is securely clamped in the headstock and rotated at high speeds. The cutting tool is mounted to the carriage and can move in multiple axes to cut material as the workpiece rotates.
CNC lathes follow program instructions from CAD/CAM software to position the cutting tool and perform different turning operations like facing, boring, drilling, grooving, and threading. Precision ground leadscrews move the carriage and cutting tool based on programmed coordinates, speeds, feed rates, and other parameters. This automation results in fast, accurate machining.
Types of CNC Lathes
There are several types of CNC lathes designed for different turning applications:
- Vertical lathes - Oriented with spindle in vertical position, ideal for machining larger diameter parts. The cutter moves vertically parallel to the axis of rotation.
- Horizontal lathes - Spindle is parallel to the ground, optimal for high precision turning of small to medium parts. The cutter moves horizontally across the face of the part.
- Chucking lathes - Uses collets or chucks to grip workpieces, versatile for bar and shaft type turning operations.
- Bar feeders - Feeds bar stock through spindle to allow for production turning of multiple parts.
- Multi-axis lathes - Additional axes besides X and Z allow for more advanced operations like contouring, tapering, profiling, etc.
- Twin spindle lathes - Has two spindles working simultaneously, doubling production output.
CNC Turning Operations
Common turning processes done on CNC lathes include:
- Facing - Machining the end surface of a workpiece flat and perpendicular to its axis. Prepares part for further operations.
- Roughing - Removing large amounts of material to roughly achieve desired shape. Uses deeper cuts and lower feeds.
- Finishing - Final pass with fine cuts to obtain smooth surface finish and high dimensional accuracy.
- Boring - Enlarging interior surfaces by moving single point boring bar along axis. For precise internal dimensions.
- Grooving/parting - Cutting grooves and recesses or parting off finished parts from bar stock.
- Drilling - Creating holes axially in the center of workpieces. Performed with rotating drill bits.
- Threading - Cutting helical threads inside holes or on outer diameters. Multiple pass process to create precise screw threads.
- Taper turning - Shaping workpiece to create angled/tapered diameters. Done by offsetting tool position or tailstock.
- Profiling - Shaping complex and concave/convex contours by interpolating tool in multiple axes.
Benefits of CNC Turning
There are many advantages to using CNC turning:
- Higher accuracy and precision compared to manual turning. Tolerances within 0.001 inches are achievable.
- Ability to produce complex geometries and contours using multi-axis capabilities.
- Faster production times due to computer driven automation. More parts produced per hour.
- Less skilled labor required. The CNC program guides the machining process.
- Quick changeover between jobs. Minimal setup time with stored CNC programs.
- High repeatability. CNC ensures each part is machined identically.
- Intricate operations like threading, grooving are handled precisely.
- Safer with reduced operator involvement. Protective guards around moving parts.
- Increased tool life and optimized cutting parameters derived from CNC.
- Reliable unattended production. CNC lathes can run 24/7.
Overall, CNC turning utilizes programmable automation to accurately and efficiently machine high quality precision turned parts. The computer numerical control enhances productivity and capabilities compared to manual turning methods. CNC turning is an indispensable manufacturing process used globally across many industries. CNC Milling CNC Machining