This is a fix for the two z axis threaded rods on an ordbot binding up. Unless they are perfectly aligned, as the axis travels up and down it can bind up causing skipped steps and ruined prints.Unscrew the metal block from the frame, and screw this block instead. The threaded rod threads onto the metal block, which sits below the printed part, with its too-big hole. This allows the threaded rod to wobble around without binding up. I believe it will introduce a small amount of backlash into the z-axis, but that's better than binding up and skipping steps.