Want to understand more about interpolation? Say, for example, you wish to move only one linear axis in a command. Say you request to move the X axis to a location one inch to the right of program zero.

In this circumstance, the command X1 would be used (assuming the total mode is instated). The machine would move along a flawlessly straight line during this drive (since only one axis is moving).

Now let’s say you wish to include a Y axis movement to a location one inch overhead program zero in Y (with the X movement). We’ll say you are trying to machine a tapered or chamfered exterior of your work piece in this command.

For the regulator to move along a flawlessly straight line to get to the programmed finish point, it must flawlessly synchronize the X and Y axis actions. Likewise, if machining is to happen during the motion, a motion rate (feed-rate) must also be stated. This needs linear interpolation.


Throughout linear interpolation commands, the control will exactly and automatically calculate a series of very small single axis departures, keeping the tool as close to the programmed linear path as possible. With today’s CNC machine tools, it will seem that the machine is moving in a perfectly straight line of motion.

Other Interpolation Forms

Dependent on the machine’s application, you may find that you have other interpolation forms available. For a second time, CNC control builders try to make it as easy as possible to program their controls. If an application needs a special kind of movement, the control builder can give the applicable interpolation type.

For example, many machining center users do thread milling operations on their machines. Throughout thread milling, the machine must change in a circular manner along two axes (usually X and Y) at the similar time a third axis (usually Z) moves in a linear way.

This allows the helix of the thread to be correctly machined. This motion looks like a strengthening motion (though the range of the spiral remains constant).