For some thing new I decided to have a go at doing a batch of four lever lock arms two right hand and two left arm out of 6061 alloy I used 2d adaptive , 2d contour, thread milling and chamfering, but after adjusting the feeds and speeds before machining the fourth part some thing very strange happened in the second last operation the 2d contour around the outside of the part the spindle speed was ramping up and down if you have any ideas about this please leave a comment ok . Well I got a lot out of making these parts and I hope people get something out of watching the video, cheers Bill