Abstract: A workpiece positioning device includes a frame; an elevator assembly mounted on the frame for motion along a z-axis; an inclined plane assembly attached to the elevator assembly; and a drive assembly mounted on the frame and configured to cause the elevator assembly to move along the z-axis, the drive assembly including a slide member and a bearing positioned in a first end portion of the slide member (which is formed in the shape of a wedge) to contact the inclined plane assembly. The drive assembly further includes a leadscrew for driving the slide member toward and away from the inclined plane assembly. The bearing is positioned in the first end portion of the slide member such that a portion of a circumference of the bearing protrudes from a surface of the first end portion of the slide member such that the bearing contacts the inclined plane assembly at a single point to cause the elevator assembly to move along a z-axis as the slide member is driven toward and away from the inclined plane assembly.