A workpiece support mountable onto a workpiece conveyor, the support including a rigid vertically upstanding member, which is vertical when mounted onto an upper-most surface of the workpiece conveyor, and a cap mounted onto the upstanding member. The cap includes a housing defining a cavity. The housing is substantially entirely sealed around the cavity so as to inhibit detritus entering the cavity. The cavity has an opening at a lower-most end thereof. The opening is for snug mounting of the cap onto the upstanding member when the upstanding member is journalled snugly in the cavity.