[M-man]

If I make a small taper. ex W-200U0.05, metric.. I get some visual "rings" every 17th mm, I can feel them too, a straigth cut in z direction doesnt give me this kind of surface. Any ideas?

[DocHod]

Could be the material that you are using I had this happen to me I was machining 4140 hot roll and had the same problem , to test this out to see if it does it all the time you will need to try to machine a different type of material with the same program to see if you get the rings that you are talking about if that doesn't do it you may have slop in your ball screws or your gibbs may need adjusting , hope this helps.