Bulkweigher for your N Scale layout. Combine with Ladders for Bulkweigher,
https://www.shapeways.com/product/BE83UXT28/?key=54a955ce47cff46fefc22573ed63f13d , to get access to all levels of the Bulkweigher.
Hint: Soak in Bestine overnight prior to painting. Not intended for children under 14 years of age.