Originally Posted by
DouglasR
Generally, the rigid tap function (M29) is set to what the factory thinks is the lowest the machine can safely go. Bert is correct, for 0iM-D and 0iM-F. However, I would caution against going below what this is set to. You didn't mention what model machine and which spindle it has. Many of the high speed spindle options have very little torque at low RPMs and tapping is a very torque demanding application. I saw someone set this to 50 RPM and had the machine stall mid-cut, forcing him to unclamp the tool from the holder manually and then retracting "Z" as the machine didn't have the tap retract function.