What is Dwell?
By specifying a dwell (G04), the execution of the next cnc program block is delayed by the specified time.
A program dwell time can be created at any point within a program.
Fanuc G04 Dwell time is a non-modal G-code.
G04 Dwell time is from G-code group 00.
Some CNC programming cycles have their own dwell facilities within the cycle itself.
Fanuc Dwell G04Format
G04 X… (sec) G04 U… (sec) G04 P… (msec)
The dwell time starts at the moment when the tool movement speed is zero.
With address P no decimal point is allowed.
Fanuc Dwell G04 Examples
G04 P1000 (equals 1 second)
so to program 10 Seconds dwell
G04 X10 G04 U10 G04 P10000
G04 X2.5 (dwell time = 2.5sec) G04 P1000 (dwell time = 1 sec = 1000 msec)
How dwell for Specified Revolutions?
Fanuc Dwell G04 pause in seconds.
It is possible to have the pause in number of revolutions by using following formula,
Seconds of pause for one spindle revolution = 60 / S (spindle speed in rpm)
If the spindle rotates at 300 rpm, the pause time for one revolution will be 60 / 300 = 0.2 seconds
If a pause is required equal to 3 rpm,
G4 U0.6 (0.2 seconds x 3 rpm)