MakerBot Print is our newest print-prepration software, which supports native CAD files and STL assemblies,
allows you to interact with all your printers via the Cloud, and many other exciting new features.
I model in 1:48 scale in general, to scale down to 1:72 use the scale tool and reduce to 0.67 or 66% I think the same can be applied to O to HO/OO, to scale up from 1:72 to 1:48, multiply by 1.50, 150%. I think n scale is 1:144, so to scale up to O scale multiply by 4, 400% but there is a conversion table on wikipedia. I approximate O scale to 28mm , and 1:48.