Mexican Train Game Hub

Our Mexican Train game has a sloping space where you put the trains, and they fall off during play. The two versions of the hub here have (a) a flat ledge for the trains, and (b) 3 mm indentations to help hold the trains in place. UPDATE: The version with the indentations had one train indent that was smaller than the rest by 2 mm in width. The new 3mf file has fixed that. The white and green hub in the images shows the fixed version.