What is a machining centre?

A machining centre is a CNC machine tool for milling, drilling, tapping and boring that changes tools automatically from a magazine, so it can run several operations in one setup. There are vertical machines, with the spindle coming from above, and horizontal ones, with the spindle from the side and usually a rotary table. Three linear axes are the baseline; a fourth axis, or two rotary axes for 5-axis work, adds reach. On the shop floor it is often just called the mill.

What decides which work a machining centre can take?

Which work a machining centre can take depends on envelope and table load, kinematics, spindle power, torque and speed, the tool interface and number of magazine pockets, the stiffness and thermal stability of the machine, and the control. A horizontal machine reaches several sides of a workpiece in one setup through its rotary table, and chips fall away more easily; it often carries a tombstone holding several workpieces. A pallet changer lets you clamp outside the machine while the spindle keeps cutting.

How does a machining centre work in practice?

Machining centres differ widely in hourly rate, from a small vertical 3-axis machine to a large horizontal with a pallet system. Which machine makes a part most economically depends on the number of setups, access to the features, metal removal, batch size and machine load. If an order's tool set does not fit in the magazine, tool changing becomes setup time. With a pallet changer part of the setup moves outside the machine: the labour remains, the spindle stands idle less.

What is a machining centre often confused with?

A machining centre is not a lathe: in milling the tool rotates; the workpiece is held still or moved by the table and rotary axes, but does not spin as the cutting motion. Some machining centres have a table that can also act as a turning spindle; that is the reverse approach to a mill-turn centre, which is built up from a lathe. A CNC milling machine without an automatic tool changer is usually not called a machining centre.

How do you see a machining centre in Blake?

Each machining centre sits in Blake with its envelope, axes and own hourly rate. For a part you see a first check per machine on envelope and axes, with the deciding limit. More on milling.