My cnc unit has slight moves along Y axix

[nitro270]

any body has idea why my CNC machine has an unwanted moves along Y axix
it is a milling unit ( 5 axis) and moves about 1 mm along Y axis every min of work, so is not consistent
any help appreciated

[phred]

hello
i have had similar problems on my mill
i would suspect electrical interference ,this can originate from motors with brushes that are worn
also from electronic motor controllers , or just a loose connection.
is it a new machine or has the fault arisen after some use?
phred