Abstract: In a numerical control apparatus, a speed difference ?S between a program command value Sc of spindle speed and a spindle rotational speed Sov to which a spindle rotational override is applied is determined. From the speed difference ?S and a pitch command value P and a response sensitivity K of a servo system during thread cutting, a follow-up error variation ?Z of a feed axis caused by the speed difference ?S is calculated. The follow-up error variation ?Z is converted into a delay time Td of a movement start of the feed axis based on the thread pitch command value P during the thread cutting. And the movement start of the feed axis is carried out behind the converted delay time Td.

Abstract: A numerical controller designed to reduce a wait time between power turn-on and machine activation. When power to the numerical controller is turned on, programs of additional functions are each selected to be either transferred or not. The selection is made by setting each of the programs of the additional functions either to be transferred or not on a display screen or by an external input signal inputted from a machine operation panel or the like. Only the selected system programs of the additional functions are transferred from the nonvolatile memory to the volatile memory. At the time of the power turn-on of the numerical controller, only the system programs of the additional functions to be used at the moment are transferred. The data to be transferred from the nonvolatile memory to the volatile memory is thus reduced, and the transfer time is shortened. Consequently, the wait time between power turn-on and machine activation is reduced.

Abstract: A numerical controller capable of performing synchronous control of a master axis and a slave axis in different control systems at a desired ratio and with a desired relation in phase. A workpiece attached to a master axis of a first system is machined into a first gear by a rotary tool attached to a slave axis of the first system and machined into a second gear by a rotary tool attached to a slave axis of a second system. Synchronous motion amounts of the slave axes are obtained by multiplying a motion amount of the master axis by set synchronous ratios to be converted into motion amounts of the slave axes. The synchronous motion amounts are added to the motion commands for the slave axes to drive the slave axes, so that the slave axes are driven at the set ratios in synchronism with the master axis. Further, the motion commands for the slave axes are compensated such that positional phases of the slave axes have set relations with respect to a positional phase of the master axis.

Abstract: In a numerical control apparatus, a speed difference ?S between a program command value Sc of spindle speed and a spindle rotational speed Sov to which a spindle rotational override is applied is determined. From the speed difference ?S and a pitch command value P and a response sensitivity K of a servo system during thread cutting, a follow-up error variation ?Z of a feed axis caused by the speed difference ?S is calculated. The follow-up error varitation ?Z is converted into a delay time Td of a movement start of the feed axis based on the thread pitch command value P during the thread cutting. And the movement start of the feed axis is carried out behind the converted delay time Td.