G76 CALCULATION FOR A "G 2 1/2" THREAD?

[flidstik]

Hello,

I am trying to calculate the G76 program co-ordinates for a G2.5 thread?it is 11 TPI,major diameter is 75.184,minor
diameter is 72.226,pitch diameter is 73.705.
Can any one reply with an example of a 2 line G76 program using fanuc?

I have previously programmed unc threads with a 14TPI and feed of 0.714.
any advise would be appreciated.

 

[desertfox]

How about this I found:-


Example: G76 Threading Cycle in 2 line format for OT and later controls.
2" diameter, 20 Threads per Inch, Mild Steel.
O2006*
N1 G50 S1500*
N2 T0101*
N3 G97 S700 M3*(Speed for threading, always in RPM)
N4 G0 X2.2 Z.2 M8*(Rapid to above part, .2" from face)
N5 G76 P021060 Q20 R5*(The first 2 digits in P represent the amount of finish passes, the next 2 are the pullout distance at the end of the threading motion, expressed in tenths of revolutions, the 60 is the angle of the tool)
N6 G76 X1.94 Z-1.0 P300(total thread depth) Q150(depth of first cut) F.05*
R if needed is the amount of taper over total distance in thread motion.
The P value is figured by taking the F-value times the constant of .6, once figured you also have the X value.( The actual value is P times .62 but its safer to use .6 as a constant and the correct the size by using an offset)
N7 G0 X6.0 Z6.0 M9*
N8 M30*

 

[flidstik]

Ok,thanks for your help.I will give it a try later today.