Plexiglass railing holder for plywood.

thingiverse

This rounded clip securely holds Optix 0.09" plexiglass vertically, designed to be screwed directly onto plywood for maximum stability. Its primary function is to prevent derailments on overhead HO scale model train tracks, which can become catastrophic - an 80" drop in real life equates to a heart-stopping 580 foot scale drop that's sure to destroy any locomotive or rolling stock. To secure the clip firmly to plywood, use Spax #6 0.5" multipurpose construction screws, which can be purchased at affordable prices from nearby big box hardware stores - usually around $2 per pack of 50 screws. The plexiglass simply drops into place within the top clip, where gravity takes over and holds it securely in position.