The risk of not choosing the right CNC machine can be catastrophic – from rejected parts, high machining costs, inconsistent tolerance to massive loss in revenue.
With many CNC machines available in the market, at times it can be difficult to select the right machine. In this guide, we will help your team make the right manufacturing decision between turning centers and machining centers.
What is Turning Center?
In turning centers, the workpiece is rotated at a very high speed with a stationary cutting tool removing the unwanted metal in a predetermined manner. The machine is capable of producing cylindrical or radial parts, shafts, bushings, and spindles with outstanding concentricity and diametrical precision.
Types of Turning Centers
Horizontal Turning Centers
This is one of the most popular types of turning centers employed in production. It features a horizontal spindle axis that holds the workpiece and is known for its short cycle time, excellent chip removal capabilities, and suitability for manufacturing high-speed shafts and bushes.
Vertical Turning Centers
In vertical turning centers, the workpiece is held by a vertical rotating table. Such machinery is well-suited for producing heavy, large disc-like workpieces due to gravity support.
Multi-Axis Turning Centers
The turning centers can be set up on up to 5 axes, which include the C axis, Y axis, and live tooling operations.
This type of equipment will help you minimize parts handling, avoid misalignments, and significantly reduce the manufacturing time of intricate parts with eccentric designs.
Swiss-Type Turning Centers
The Swiss-type turning centers employ the guide bushing technique to clamp the workpiece, which ensures excellent stability during machining operations. These centers produce precision parts suitable for use in watches, the medical industry, and aircraft fasteners.
What is a Machining Center?
Machining center is popular for its stationary configuration, where it holds the part still and firm at the table while a tool moves along various guideways.
The machining center performs processes such as drilling, milling, boring, tapping, and shaping as a single process. They are specifically made for prismatic parts with complicated features.
Types of Machining Centers
Vertical Machining Centers (VMC)
VMCs position their spindle vertically and are the most commonly used machining centers for typical manufacturing operations.
Vertical machining centers are suitable for processing flat workpieces, molds, and plates; they demonstrate relatively easy programming, chip removal, and affordable initial costs compared to other machining centers.
Horizontal Machining Centers (HMC)
In horizontal machining centers, the spindle is mounted horizontally, which is ideal for efficient chip removal and processing multiple faces of workpieces using pallet changers. They operate faster than vertical machining centers for your continuous production facilities, especially when handling complex parts.
In 3-axis machining centers, the cutting tool moves along the three axes, X, Y, and Z. These machining centers will provide an affordable starting point if you are producing components without undercuts, angles, or multi-sided processing needs.
A 4-axis machining center incorporates a rotary A axis to the conventional 3-axis machine. This makes the machining process easier and faster; you can operate one component from several sides without repositioning it.
This machining center features two additional rotary axes that allow simultaneous processing of multi-faceted surfaces. Besides, this machine produces aerospace impellers, turbine blades, and orthopedic implants in a single setup without any need for part relocation.
Differences between Turning Centers and Machining Centers
· Operating Principle
While in machining centers, the workpiece remains stationary as the cutting tool rotates on various programmed axes, turning centers utilize the rotation of the workpiece against a stationary cutting tool.
Therefore, it is important to align the machine working principle to match the required part specifications. For instance, the working principle of turning centers involves the manufacturing of cylindrical parts. On the other hand, the working principle of a machining center favors complex parts manufacturing and flexible production processes.
· Part Geometry Capability
Unlike turning centers, which manufacture cylindrical parts and symmetric shapes such as shafts, pins, and bushings. Machining centers produce block-shaped pieces with slots, pockets, holes, and complex contoured surfaces.
By choosing machining centers for multi-face machining operations and turning centers for concentric parts, it is easier to eliminate bottlenecks in the entire machining process. This is critical in improving machining efficiency and consistency.
· Axis Configurations
During setup, machining centers move from 3 axes to 5 axes concurrently, while standard turning centers use 2 axes (X and Z) and C and Y axes when in their advanced stage.
It is important to note that the expanded axis configurations allow for a versatile machining process. With such expansions, it reduces the cost of secondary operations, which can be costly.
Additionally, with more axes, it implies that with only one machine setup at a time, it’s easier to handle different machining operations. This improves precision and production.
· Tooling Differences
In contrast to turning centers, where the operator attaches a single-point tool to a turret with interchangeable tooling spindles, machining centers have multi-point rotating tools attached to automatic tool changers that hold 20 to 120+ tools.
With the turning machine configurations, CNC parts manufacturers can achieve a repeatable production workflow. On the other hand, the automatic tool changers can handle a wide range of cutting options without reinstalling the tooling system. This minimizes manual intervention, while supporting complex multi-process machining.
· Production Speed
Turning centers have a reputation for producing large volumes of cylindrical parts with small variations in arrangements at higher speeds.
Machining centers, on the other hand, work well for low-to-medium production volumes when various parts and job preparation define the operation.
When you match the equipment and expected production speed, it is easier to optimize the utilization rate. This will eventually translate to manufacturing profitability.
· Precision and Surface Finish
With good, timely maintenance, both machines have a tolerance of ±0.005 mm, which is recommended in high-performance fields.
Unlike turning centers, which achieve accuracy with relation to concentricity and diameters, machining centers rely on the positioning of various features on multi-faced parts.
By carefully paying attention to precision and surface finish, you can reduce scrap rates, while also improving product quality
· Cost
Turning centers provide less capital investment for cylindrical shaping than machining centers.
Although the upfront costs of machining centers are generally high, they fabricate highly complex and costly workpieces that require multiple machining processes in a single setting, thus generating a maximum return on investment.
Practical Applications
Where to use Turning Center:
Automotive: Car automation is evolving worldwide, and machines such as turning centers are gaining more attention for large-scale production.
They manufacture crucial auto components like crankshafts, axles, and wheel hubs in large quantities and with high dimensional tolerance from each batch.
Aerospace: Turning machines fabricate complex parts that are durable and lightweight with efficiency and precision, e.g., engine shafts, landing gears, and hydraulic actuators to ensure the safety of the airplane.
Medical Equipment: Turning centers produce sensitive implants, joints, and artificial tooth devices, which require high levels of accuracy and smooth surface texture because they directly impact not only the medical equipment but also the patients.
Electrical Components: In today’s economy, electricity runs everything, from businesses, agriculture, medical facilities, and institutions.
Therefore, turning center machines are in demand for high-volume production of connectors, terminals, and pins.
Industrial Machinery: To compete in the modern market and reduce manufacturing time, you require the accuracy of turning centers for precise pump shafts, valves, pistons, and other critical mechanical components.
Where to Use Machining Center:
Automotive Industry: The automobile sector depends on machining centers to machine engine blocks, transmission housings, brake calipers, and suspension knuckles.
They perfectly perform all the operations you need and feed them in a single setup, making the manufacturing process fast and economical.
Aerospace Industry: The aviation sector uses a 5-axis machining center to manufacture highly intricate turbine blades, fuselage structures, and wing ribs.
They reduce material wastage by adjusting the cutting tool across the 5-axis with the correct positioning within very tight specifications.
Electronics Industry: Electronic engineers employ machining centers to design and manufacture heat sinks, enclosures, circuit board frames, and connector bodies with the exact positioning of features necessary for their reliable operation.
Precision Engineering: In engineering, precision mechanics use machining centers to create dies, molds, jigs, and fixtures of irregular shapes and true dimensions.
This ensures quality-sensitive operations in subsequent production processes.
Custom Solutions: In this new era of innovation, customers come up with new concepts daily.
Thanks to machining centers, they create tailored spindle speeds, layouts, and individual processing capabilities, allowing you to produce whatever design your clients need.
FAQs
What is Turn-Mill Center?
This is a machine that integrates the two processes, both turning and milling, into one single operation to enable you to perform an efficient, complete machining of a part using only one clamping.
What are the limitations of turning centers?
Downsides of turning centers include: high initial costs, non-circular shapes, surfaces with complex angles, prismatic parts, and parts that demand tooling on various planes.
What are the limitations of machining center?
The machining centers, on the other hand, require very well-trained operators, enough time to set them up, and they also encounter problems in managing the wear and tear in large-scale cylindrical parts production.
Is machining center the same as turning center?
Not really. The machining center uses the principle of rotating the tool to generate prismatic components, whereas the turning center uses the workpiece to revolve in it to make round or cylindrical parts.
Is CNC lathe the same as turning center?
No, they are different. When operating a CNC lathe, you will realize that it usually uses a 2-axis principle with a single spindle.
A turning center, on the other hand, has been upgraded into a much more sophisticated 5-axis machine.
Need Help in Selecting the Right CNC Machine?
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