NCT Group NCT 2000T, NCT 100T, NCT 990T manual Override Switches, Feedrate Override Switch

9 Override Switches

9 Override Switches

The control can operate three override switches:

–the feedrate,

–the rapid traverse, and

–the spindle speed override switches.

9.1 Feedrate Override Switch

The feedrate override switch has 16 positions. The feedrate switch determines, by how many percent of the programmed feedrate (F) should the axes be moved. The diagram beside shows the position of the switch and the percentage belonging to the position. Position 0% stops the movement of not only the feed, but also of rapid traverse movements.

In basic configuration feedrate override switch can be selected on OPERATOR’S PANEL or POSITION screen. After pressing the action menu key, action F4 % must be selected. This way the percentage can be decreased (by means of softkey F–), as well as increased (by means of softkey F+).

The NCT machine control board is mounted with a

16-position rotary switch. In this case in place of

the above mentioned override adjustment with

softkeys this feedrate switch can be used.

The feedrate switch position is interpreted in jog mode on the basis of parameter adjustment. If the value of parameter 1372 JOGFEED is 0, the speed of jog is the modal

value F. If the value of parameter 1372 JOGFEED is 1, the control registers the speed fixed in table on the basis of feedrate switch position. (See table of jog mode.)

In the following cases the feedrate switch is ineffective:

–G63, i.e. state of override disabled,

–at the values of variable #3004 listed in programmer’s manual, and

–during thread cutting G33, G34, G76, G78 and tapping cycles G84.1,

switch	%
state
1	0
2	1
3	2
4	5
5	10
6	20
7	30
8	40
9	50
10	60
11	70
12	80
13	90
14	100
15	110
16	120

G84.

In these cases the control always supposes 100% independent of switch position.

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