What is CNC Turning?(cnc laser cut Ingram)

  • Time:
  • Click:9
  • source:ESKRIDGE CNC Machining
CNC turning is a machining process that uses computer numerical control (CNC) to automate the turning of parts on a lathe. It enables precise control over the machining of cylindrical parts and can produce intricate features, shapes and finishes.
How Does CNC Turning Work?
A CNC turning center consists of a lathe that has been retrofitted with CNC capabilities. This means it is controlled by a computer that follows a programmed set of instructions to cut material from a workpiece. The steps in CNC turning are:
1. The operator loads a program into the CNC control which defines the actions needed to produce the desired part features. Common CNC languages like G-code are used to program the motions.
2. The raw material, usually a rod or bar of metal, is loaded into the machine and clamped in the chuck. The chuck provides the rotating drive that will spin the material during machining.
3. The cutting tool is mounted into the tool turret or tool post at the appropriate height for machining. Common turning tools include bits for facing, boring, turning, grooving, cutting off and threading.
4. The operator starts the program execution which initiates the machining sequence. The turret will index to bring the needed tools into position above the workpiece and the chuck will rotate the part at the defined speeds for turning.
5. As the part spins, the cutting tools are fed towards the workpiece and make cuts according to the programmed contours and dimensions. Slower speeds are used for facing off material and hitting final dimensions while higher speeds are used for rough cutting and stock removal.
6. Cutting fluid is pumped over the work area to cool the material and tools while also flushing away chips. The fluid helps prevent heat buildup and tool wear during machining.
7. Once the program finishes, the machine retracts the tool turret, stops the chuck from spinning and indicates the program is complete. The finished part is then unloaded.
CNC turning centers are able to produce parts unattended, often overnight, enabling high volumes of parts to be machined. The CNC capability provides precision, repeatability and accuracy during turning.
Features of CNC Turning
Some of the key features and benefits of CNC turning include:
- Automation - Parts are produced without an operator needing to make manual adjustments during the process. Human intervention is only needed for setup and program changes.
- Accuracy and Repeatability - The computer control minimizes variation in the process and can repeatedly hit tolerances within 0.001 inches or better. Manual turning processes can't achieve the same level of precision.
- Complexity - CNC allows the production of parts with complex curves, threads and profiles that would otherwise require multiple turning operations or secondary processes like milling.
- Quick Changeover - Changing from one part to another simply requires loading the new part program. No mechanical adjustments are necessary with the tools preset in the turret.
- Reduced Labor - One operator can run multiple machines. The automation increases productivity without extra staff.
- Intricate Features - Precise boring holes, threads and grooves can be added via CNC. Special tooling and techniques enable micromachining for small delicate parts.
Applications of CNC Turning
CNC turning is ideal for producing parts that require rotational features and fits a variety of manufacturing applications:
- Automotive - Engine valves, pistons, transmission shafts and bearings
- Aerospace - Bushings, fasteners, fittings and engine components
- Medical - Small implanted devices, surgical instruments, orthopedic joints
- Military/Defense - Missile, rocket and artillery shell casings
- Fluid Handling - Fittings, nozzles, ball valves and pump shafts
- Fasteners - Screws, nuts and bolts
- Electronics - Connectors, insulators, lenses and switch components
Advantages of CNC Turning
Some of the main advantages of CNC turning include:
- Higher Production Rates - The automation facilitates high volumes without relying solely on operator skills.
- Better Quality Control - The computer numeric control improves consistency and enables statistical process control.
- Lower Labor Costs - One programmer and machinist can run multiple machines reducing direct labor requirements.
- Less Waste - CNC optimizes tool paths saving material compared to manual methods. Minimum excess stock also reduces waste.
- Safer Working - Removing the need for manual machining improves the safety of the operator and reduces accidents.
- More Flexibility - Quick changeovers let machines adapt to new part production with minimal downtime for retooling.
- Part Complexity - Intricate contours, threads and profiles can be machined in a single setup that otherwise would require multiple operations.
Disadvantages of CNC Turning
Some potential downsides to CNC turning include:
- Higher Machine Cost - The CNC components increase the initial capital investment compared to basic manual lathes.
- Tooling Costs - A wide assortment of cutting tools are needed to fully utilize CNC capabilities. This expands upfront costs.
- Programming Time - While shorter runs can use canned cycles, programming complex parts or long runs from scratch takes time and skill.
- Operator Training - Machinists have to learn programming basics and CAD/CAM software to program and operate CNC machines.
- Maintenance Requirements - Preventative maintenance must be performed on the computer components to keep the machines running accurately.
- Part Size Limits - Large diameter or long parts may exceed the capacity of a typical CNC turning center. Larger machines are considerably more expensive.
Getting Started with CNC Turning
Here are some recommendations if you're considering adding CNC turning capabilities:
1. Assess part sizes and production volumes. Make sure CNC turning is well-suited and can handle the necessary capacity.
2. Evaluate different CNC turning machines suited for your parts. Factors like power, accuracy, torque, and tool capacity should align with your needs.
3. Budget for cutting tools, workholding, programming software and initial training. Tooling takes ongoing investment as parts change.
4. Hire a skilled CNC machinist or plan to train existing staff. The programmer must know G-code, CAM software and machining practices.
5. Implement scheduling, workholding setups, maintenance routines and quality control for the CNC area. This infrastructure enables smooth production.
6. Start with simpler turning operations and allow complexity to increase over time. Get the foundations in place before taking on challenging parts.
With the right groundwork, CNC turning can significantly boost an operation's productivity and part quality. The automation and precision opens many possibilities over basic manual turning methods. By leveraging this technology appropriately, manufacturers can access new opportunities and grow their business. CNC Milling CNC Machining