What's new
What's new

G84 face taping with sub spindle.


Feb 7, 2019
Hey, I am fairly new to this site. We have been creating a program for this new part at work. The machine we are using is a NexturnSA20B. Ultimately in the end the part is only .366 in length and the material is 303 stainless steel. It's a hex nut with a cone on the end essentially and the center of the nut gets tapped with a M8 self lock. Now our fanuc control Nexturns have been taping with M8 self locking taps for years with the vertical tool rack. Same 303 material and the distance is twice that of the locking nut we are making.

So we pick the part up on the cone end with the sub spindle and then we spot and chamfer the end of the nut on the center of the through hole. After we have to tap with the M8 self lock. Now we have gotten the spindle to tap this part but it wont keep doing it continuously. Eventually it will stall at the lead of the tap and give a sv0410 C Excess alarm. We are driving using the live tooling on the sub side. Also starting at z.65 to give it momentum infront of the tap for momentum. This is how the program looks.


If the spindle is refrenced to 0 just like we have it doing in the program it will start giving the c excess alarm. Its almost like once it meets contact with the tap, the tap is trying to drive the spindle head past 0 so it alarms. I have tried so mant different iterations in the program, such as using a m103 for the sub spindle to run the rigid tap mode and using a static holder for the tap. Also have tried IPR. The program above is the best of those iterations. I think it has something to do with the spindles positioning and timing. Was wondering who could be of help. If the m50 isnt in the programing to initiate milling the spindle will just sit in front of the tap and not read the g84. If I try and lock the spindle with a m70 its pointless because of the m50. The position screen even reads the c2 axis as rotating during this canned cycle.