We have an older 4020 vmc with fadal cnc 88 controler.
when drilling it will sometimes go's to wrong position, starts to drill, then it will try to go to correct position, causing crash, or while milling, feed will hesitate, then rapid over to where it thinks it should be; not good.
This problem is intermittent, we have had techs out swapping cards, jiggling wires etc., Problem doesn't happen when they are around. can anybody
help?