Hi:
I'm having problems with a tapping cycle on a 3 X VMC with a FAGOR 8055iA milling control. The tap keeps on pulling itself out of the holder on the retract part of a G84 cycle ( I think). I read the tapholder instructions, and made sure to use R=0 (floating tapping cycle). I have tried to use some dwell (K=200) and also tried reducing the feedrate to 49 IPM on Tapmatics advise. They say to reduce the feedrate by up to 5% on through hole tapping.
Material= 6061 T6 1/4 thick
Tap: 1/4-20 Spiral flute
tap drill=#7
RPM=1000
Feed= 50 IPM, also tried 47.5,48 and 49 IPM
Floating Tapholder=Tapamtic NS4 with a jacobs rubber collet sized for a .257 OD shank.
Cooloant= Flood semi synthetic
My gut tells me that I may be using up the float (.25 inch) when I get to the bottom of the hole, and the spindle may be continuing to rotate.(After all it only takes 5 revs to eat up .25 inch).
Then, when it retracts, I may have already used up my travel with the holder, so the tap has no choice but to be pulled out.
Not only am I pulling out the taps, but I'm beginning to pull out my hair on this one. I'm not blessed with alot of hair to begin with.
regards