I created this cover system for a production DeskTop to protect the exposed Y-axis rails from swarf, chips and dust. The prototype was made with plastic angle stock attached to the gantry vertical above the bearing blocks and plastic sheet stock was mounted to the frame, covering the rails and overlapping the angle stock. All was attached using double stick tape. In use, the covers have kept the rails much cleaner and have held up to daily production use. At some point I'll install a few hold down screws so the covers can be easily be removed for rail maintenance.
Ed