ZigZag Loop for a marble run

Hello,I thought about a "ZigZag Loop" for our marble run and had some time...The ring is only needed 2 times, only for the 2 bottom parts.I don't glue them in, only stack together.Maybe you have to scale the ring a little bit, so it fit into the bottom plate.Video 1Update 23.08.20: Added some more tiles, if someone can use them. Video 2Update 10.02.21: Added 5mm higher tiles. ("H" for "high", in the name), the rail get a little bit steeper, and the marble got more spe