Sliding Under Cabinet Shelf

I wanted a shelf under my HO scale model train layout that would store under the table and slide out when I was playing with the trains. The shelf needed to be large enough to accommodate the power supply, (transformer), and various electrical switches. The ready-made shelves that swing up and out are perfect, but way above my budget, which brought me to ...print it yourself, girl!. So here it is. Still in process, as I've not yet printed it. The system consists of 1) a stationary bracket that mounts under the table with the grooved side down. The outside edge of the bracket is closed so that the shelf bracket won't keep sliding completely off the slide. 2) sliding brackets, the ends of these 4 pieces fit into the top of the shelf bracket and will be glued into that bracket, then the other end fits into the stationary bracket. The slider and the shelf bracket had to be printed separately to fit my Longer LK4 print bed. The top of the sliding bracket fits into the grooves in the statio