These Z Axis supports for left and right rods can be adjusted to suit the precise dimensions of your Robo 3D. Brackets fit to the case using 1" double sided foam or mounting tape. Fit the brackets loosely first and mark with a pencil where each bracket needs to stick. Make sure the bracket tab is on top so it is easier to remove the case later. Before tightening up the M4 nuts make sure the X Axis carriage moves freely up and down the Z Axis.