I think something that was left out on this was the machine in question that did not do weel witht he fanuc control (coming from my friend shop who useses fanuc and heiednhim (sp) controls) they had to replace the machine, it was nto the control as first thought. The servos could not respond fast enough to generate the hi feedrates required.. What control of fanuc were your tests performed on? Recently in s HSM test the fanuc 18i worked wonders even at 2000 IPM
.... I know my control I can change the circular spline fit of the machine and greatly affect he concentricity of a interpolated cirlce arc from lees then .0005 to greater tha .001.. All with one little change in the control parameters..