elongated holes

[Little Bit]

Hello fellow enthusiasts I have a LDR motion system 5 X10 Plasma table which I love (Dan The Man !!!!!) Hyp 85( draw Auto Cad / Sheet cam) I built a water tray for pipe that goes on the side of the table I mostly cut 2'' SCH 40 pipe a 1'' through hole at the one end then at 6'' cut off as you know its difficult to get the holes round I draw them egg shaped that helps they come out pretty round .lately not so much. The machine cuts the first hole then turns 180D then cuts the other side of the through hole Oddly the first hole comes out nice but the second hole is elongated from side to side I believe a Y axes problem one time I had the ground clamp to tight and the holes were coming out elongated the other way front to back x axes problem I have one more clue when you start cutting I might cut three or four lengths of pipe 120 holes before I start to have a problem I think it has to do with the Y axes stepper motors Cand CNC Bladrunner I think Black Box 620 oz 60 HS 100DE062 could they be worn out ? they seem to be loosing steps . thanks a bunch for listening
Having Fun
Little Bit