OK Himy was kind of correct. This problem still exists, kind of. So I don't do any rapid moves during machining anymore, I stay at 20 IPM. But I noticed recently that the problem would present itself at 30 IPM if both the X and Y were moving at the same time, such as going around a corner at full chip load, so 1/2" endmill 30 IPM and 1/4" DOC. I believe the gibs to be adjusted accurately and both axis' are solid and move smoothly. I can't move the tables by pulling more than .001 - .0005 and it's certainly not binding. When the machine is off I can turn the ballscrews by hand and they are very smooth. The only mechanical fault I would see is maybe the steppers are not strong enough for this mill under full chip load.
So PLEASE HELP ME solve this problem. Specs: Keling 1200 oz./in. Steppers -- Direct Drive to Ball Screws -- Keling 8078 Drives -- 72 VDC @ 20 Amps Power Supply (The Steppers are set to 5.7 amps on the drives). At 150 IPM it can drag me across the floor without losing steps, but that's not a very technical test and a full load cutter might be more. Is there any way this could be an electronic problem with the drives or something? If it's not an electrical thing would I get more power from a 1810 oz./in. or 2830 oz./in. Stepper with the same 72VDC Power Supply? I'm asking cause I don't know how much more power at 20-50 IPM I would get from the other motors.