My industrial CNC turning center with 2 speed geared head and 15hp spindle has a table of thread pitch vrs max threading rpm. The issue isn't as much acceleration at the start of the thread as it is being able to make a perfect 90° retract when threading up to a shoulder. On threads which are the same nominal diameter as the material a threading exit can be a 135° and can be safely pushed a bit more it you also allow lead in space at the start.
CSS with threading is generally just a bad idea. the only time I have done it was on large 2" NPT fittings running in low gear. I also write my NPT threading cycles deeper (Z) to thread out to a dia. larger than the material when ever possible. Basically think of it this way as a programmer. A G00 X command should never be found within the program path while CSS is active. Pre-calculate the required Sxxxx value for your initial positioning move and have that as your M03 S#### so that when CSS is activated the machine does not need to make an instantaneous correction. Greg, Out yonder in Yoder. ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
