Understanding ball migration

All ball bearing slides function by having rolling balls between the members, and it is this principle that enables a high load to be moved with a low force.

A common issue with all ball bearing slides is that the ball cages, under certain circumstances, can move temporarily out of position and may require additional force to fully open or close the slide.  This condition is referred to as Ball Migration, or Drawer Creep, and all slides suffer from it, not just Accuride slides.

Ball Migration mainly occurs when a drawer is partially opened, repeatedly, and not to the full extent of travel.  When this happens often enough the ball cages (retainers) start to move out of position, and because the ball retainers form part of the slide’s stopping arrangement, this causes the drawer to stop in the wrong place. This generally means that the slide will stop short of its fully open position. Sometimes the slide will neither open nor close fully, but mostly it is the open position that is affected.

If the slide does stop in the wrong place then the best way to overcome this is by forcing the moving element to its fully open or closed position by pulling on the slide or by lightly slamming it. This should overcome the non-rolling friction of the balls, and force the slide back into the correct position.