在五轴编程加工中，机床极限常常是一个困扰编程人员的问题。以Mikron ucp1350为例，如下图所示的方向，Y轴不能超过中心的140mm, Y正是500mm。这种情况下，若是伸的太远，则会使精度变差，所以会把Y轴的极限往里控制一点，让主轴头不会往外超得太远。

例如，下图所示Y轴是-240.983mm，机床未超程，若是将鼠标点在最外侧，显示-302.623mm Hc-, 说明已经超程。

http://www.qianghu.com/attached/image/20190424/20190424110024_62820.jpg 

http://www.qianghu.com/attached/image/20190424/20190424110326_81353.jpg

http://www.qianghu.com/attached/image/20190424/20190424110356_48580.jpg

http://www.qianghu.com/attached/image/20190424/20190424110418_88172.jpg

http://www.qianghu.com/attached/image/20190424/20190424110446_42571.jpg

http://www.qianghu.com/attached/image/20190424/20190424110507_55691.jpg

然后点选刀路，选择“A”,选择“Z向旋转”，选择“重新计算”，点击关闭。

http://www.qianghu.com/attached/image/20190424/20190424110611_28640.jpg

http://www.qianghu.com/attached/image/20190424/20190424110626_17733.jpg

http://www.qianghu.com/attached/image/20190424/20190424110638_69985.jpg

http://www.qianghu.com/attached/image/20190424/20190424110650_33271.jpg

计算后得到“M”没有超程的图标，此时获得的刀路完全没有问题。

http://www.qianghu.com/attached/image/20190424/20190424110705_56369.jpg

为了看的更加清楚，可以通过模拟进行确认。

http://www.qianghu.com/attached/image/20190424/20190424110743_74408.jpg

http://www.qianghu.com/attached/image/20190424/20190424110805_90818.gif

模拟后可以确认没有出现问题。

http://www.qianghu.com/attached/image/20190424/20190424110827_79932.jpg