Fanuc G72 Facing Cycle One-line Format
Fanuc cnc control has many versions with variety of different cnc programming techniques and styles.
But other fanuc cnc controls (Fanuc 10T/15T) use One-line format for canned cycles (G71, G72).
Below is the Fanuc G72 facing cycle One-line format version described in full detail.
G72 P… Q… U… W… D… F… S…
|P||Contour start block number.|
|Q||Contour end block number.|
|U||Finishing allowance in x-axis.|
|W||Finishing allowance in z-axis.|
|D||Depth of cut.|
|F||Feed-rate (overrides the feed-rates given between P block and Q block)|
|S||Spindle Speed (overrides the spindle speed given between P block and Q block)|
P & Q – The cnc program blocks between the P block number and Q block number will be repeated until the end dimension is not met.
F (feed-rate) – The benefit of using F (feed-rate) in G72 block is that during facing cycle machine will use this feed-rate, and will ignore any feed-rates given between P block and Q block program.
The feed-rate given between P block and Q block program will only be used if you call G70 Finishing Cycle later in program with same P block and Q block numbers.
This is very handy way gives cnc machinist opportunity to keep different feed-rates for “rough facing cuts” and “final finishing cut”.
S (spindle speed) – works the same way to keep different spindle speeds for roughing cuts and finish cut.