CNC machining centres: types and selection criteria
What is a CNC machining centre?
A CNC machining centre is a numerically controlled machine tool that performs milling, drilling, tapping and finishing operations automatically, with a tool magazine that allows tool changes in seconds without operator intervention. This automatic tool changer (ATC) is precisely what distinguishes a machining centre from a conventional CNC milling machine.
Whereas a CNC milling machine requires the operator to change tools manually or semi-automatically, a machining centre has a magazine holding 20 to 120 tools that are swapped autonomously according to the program sequence. This makes it possible to chain multiple operations — face milling, pocketing, drilling, tapping, finishing — in a single workpiece setup, without stoppages.
At MECVIL we operate CNC machining centres daily at our facilities in Sallent and Navarcles, with capacity for parts ranging from precision components to structures of up to 20 metres. Our experience of over 50 years allows us to select the optimum type of machining centre for each project.
Types of CNC machining centres
Vertical machining centre (VMC)
The spindle is oriented vertically, perpendicular to the worktable. It is the most widespread type thanks to its versatility and accessible cost. Typical travels: 1,000 × 660 × 635 mm, with spindle speeds from 8,000 to 15,000 RPM.
Ideal for: flat parts, plates, covers, moulds, prototypes and medium-run production. Top access makes workpiece loading and visual process monitoring straightforward.
Horizontal machining centre (HMC)
The spindle is oriented horizontally. The main advantage: gravity evacuates the swarf away from the cutting zone, which protects the tool, improves surface finish and enables longer unattended cycles. An HMC can multiply productivity by up to three times compared with a VMC on multi-face prismatic parts.
Ideal for: parts with multiple working faces (engine blocks, valve bodies, housings), series production and lights-out operations.
5-axis machining centre
Two rotary axes (A+B or A+C) are added to the three linear axes, enabling complex geometries to be machined in a single setup. It can operate in 3+2 mode (indexed positioning) or in simultaneous 5-axis mode (continuous movement on all 5 axes).
Ideal for: turbine blades, medical implants, aerospace components, complex moulds and any part requiring access from multiple angles. At MECVIL we have 5-axis CNC machining centres that reduce repositioning and eliminate cumulative errors between setups.
Gantry machining centre
It uses a bridge structure spanning the entire worktable, providing maximum rigidity for large-dimension parts. Two configurations: fixed bridge (the table moves in X) and travelling bridge (the table is stationary).
Ideal for: aeronautical panels, aluminium structures, composite components and parts that exceed the dimensions of a conventional VMC or HMC.
High-speed machining centre (HSM)
Designed for spindle speeds above 15,000 RPM (up to 60,000 RPM on specialised units), with rapid traverses of up to 120 m/min. It uses high-frequency spindles and linear motor drives.
Ideal for: moulds and dies with fine detail, thin walls, high-speed aluminium machining (>500 m/min cutting speed) and surface finishes that eliminate the need for subsequent polishing.
Not sure which type of machining centre your part needs?
Send us your drawings and our technical team will recommend the optimum process and equipment.
How to choose the right machining centre for your part
Selecting the right type of machining centre depends on four main factors:
- 1.Part geometry: does it have a single working face (VMC) or multiple faces (HMC, 5-axis)? Does it require complex curved surfaces (simultaneous 5-axis)?
- 2.Dimensions and weight: small and medium parts suit standard VMC or HMC machines. Large parts need gantry centres or fixed-bed milling machines with extended travels.
- 3.Tolerances and finish: for ISO 2768-f tolerances or tighter, 5-axis offers clear advantages by eliminating repositioning. For fine finishes (Ra <0.8 µm), an HSM centre reduces or eliminates subsequent grinding.
- 4.Production volume: the HMC with pallet changer maximises productivity for medium and long runs. The VMC is more efficient for prototypes and short runs.
In practice, many parts can be manufactured on more than one type of centre. The final decision depends on the balance between precision, cost per part and lead time. A manufacturer with a range of equipment — such as MECVIL, with VMC, 5-axis and fixed-bed machines up to 20 m — can select the optimum centre for each project without being limited to a single technology.
The machining centre within a turnkey project
A CNC machining centre does not work in isolation. In a turnkey project for special machinery, machining is one phase within a broader workflow:
- 1.[Engineering](/en/servicios/ingenieria) designs the part, optimising it for manufacturability
- 2.[CNC machining](/en/servicios/mecanizado) manufactures the part to drawing with the specified tolerances
- 3.[Assembly](/en/servicios/montaje) integrates the machined part into the mechanical assembly
- 4.[Automation](/en/servicios/electrica) adds the electrical and control intelligence
At MECVIL, these four phases are carried out in our 10,500 m² facilities, with a team of +110 professionals and ISO 9001 and EN 1090 certifications. This means we optimise part design with the available machining centre in mind, reducing programming time and maximising process efficiency.
To understand how machining centres integrate with continuous improvement principles in a manufacturing workshop, see our article on lean manufacturing applied to machining.
Machining centres and materials
Each material requires a different type of centre and different parameters:
- [Aluminium](/en/servicios/mecanizado/mecanizado-aluminio): benefits enormously from HSM centres. Cutting speeds above 500 m/min with excellent finish. Ideal for railway and aeronautical structural profiles.
- Steel and stainless steel: require centres with high rigidity and spindle torque. HMCs are preferable for their swarf evacuation capability and stability.
- Titanium and superalloys: demand centres with high static and dynamic rigidity, low spindle speed and high-pressure coolant. 5-axis centres allow shorter tools to be used, reducing vibration.
The choice between CNC turning and milling on a machining centre depends on the part's symmetry: cylindrical parts go to the lathe, prismatic parts to the machining centre.
Looking for a manufacturer with a range of CNC machining centres?
At MECVIL we operate VMCs, 5-axis centres and fixed-bed milling machines up to 20 metres. Contact our technical team to evaluate your project.