Edge distance
Work in progress: This section is still a work in progress — content is being added and revised continuously.
What is checked? Whether tracks run too close to the baseboard edge or overhang it.
Why does it matter? A train that derails at an unguarded edge falls — with an H0 locomotive that is easily three-digit damage. Experienced planners therefore keep main tracks at least 10 cm from the edge (or guard it with a raised rim/acrylic). Tracks overhanging the board simply cannot be built — unless they are a deliberate interchange/expansion stub towards the edge.
How to fix it: Shift the run inwards, shorten the end piece — or enlarge the board (sometimes it really is too small for the dream; the plan check would rather tell you before the build than after).
Numbers & defaults: minimum distance 100 mm (H0, scaled), editable — a value of your own applies unscaled; overhang is always an error.