About this 3D model

A diminutive staircase style Marblevator featuring knobs at both ends for clockwise, counter clockwise, left or right hand operation. After seeing the prototype with multicolored steps, my wife thought "Rainbow Roll" (sushi reference) was a better name; I'm sticking with Baby Steps. Uses 8mm (5/16") ball bearings as marbles. Video of prototype is here: https://www.youtube.com/watch?v=yeF4z9jjIDE. Designed using Sketchup Make 2015, and printed in PLA on a Makerbot Replicator 2 using Makerware 2.3.3.42 "Standard" Settings (.2mm layer height, 2 shells, 10% infill).