N_ G76 X_ Z_ K_ D_ I_ A_ F_
This is a brief explination on the old fanuc style thread cycles.
The G76 command automatically performs all cutting operations required to achieve a thread. From the programmed variables the cycle will calculate the toolpaths, based on the desired thread pitch, depth, and tool angle. X designates the minor diameter of thread. Z specifies the end of the thread. D designates the depth of the first pass. K specifies the depth of the thread. F specifies the desired pitch of the thread. A is tool angle. I defines a tapper line or tappered thread. +I# will mean the back of the thread will be larger than the minor dia specified by X and a -I# will cause the back of the thread to be smaller than the mionr dia. Use I on pipe threads or on long threads to compensate for machine varience over distance.
Also I believe there are also 2 other varibles you can add to leave stock for a final pass at end of cycle and make repetative dead passes.
I will check this out on 2/18/05 and repost
I will also give an example program
GOD BLESS THE CAD/CAM
NOW THE COMPUTER REMEMBERS NOT ME.