How to Make Expanding Miter Slot Runners for Jigs

What were they thinking??? Miter slots on cheap table saws miter slot INCRA Mitre Sliders are the greatest shortcut ever invented for getting a sled or other fixture tracking perfectly through a miter slot miter slot miter slot track It's a metal bar with a movable end that serves as a guide fence and slides into a dedicated slot in the table saw The miter gauge may be

miter slot runners The NoPlay Miter bar is designed for use in any standard 34” x 38” miter slot Made from aluminum, the bar will not bow or warp like some plastic or wood bars