Milling Machines

Table and travel

Table size and axis travel decide what a mill can work. X runs along the table, Y across it, and Z is the head moving up and down the column. A long table (700 mm, say) means a longer slot or several parts in one setup.

Capacity is given three ways: end mill diameter, face mill diameter and drilling diameter. End mill capacity can be smaller than drilling capacity on the same machine, because side cutting loads the spindle harder than drilling.

Variable speed or gear head?

A variable speed head sets speed steplessly and shows it on a digital display; handy in a shop that runs cutters of very different sizes. A gear head selects speed in steps through a gearbox; it gives more torque at low speed and suits large cutters.

Digital readout and power feed

A digital readout (DRO) shows each axis position on screen, so hole centres and slot lengths are measured without counting handwheel turns. A power feed drives the table at constant speed, evens out the finish on a long pass and spares the operator. On some models the X power feed is optional, on others it is fitted.