Abstract: The sliding member of a ball slide is supported for linear travel on a base member by two linear sets of ball bearings. In a typical embodiment each set of ball bearings has rolling engagement adjacent diametral opposite sides thereof with two pairs of spaced, parallel bearing rods that are housed, respectively, in longtitudinal grooves formed in confronting sides of the sliding member and base member, respectively. The spaces separating the two bearing rods of each pair thereof on the sliding member are equal to each other but greater than the spaces separating each pair of bearing rods on the base member, whereby for each revolution of a ball bearing the ball bearing will travel on the slide member at a rate lower than the rate of which the ball bearing will travel on the base member.