Is the nozzle size setting used when calculating the print head path for the outer edge?

[billplate 0]

To put my question in context, I've designed and published (as .STL files) an object, comprising mutable parts, some of which have to move. The tolerances between components are reasonably tight but fit together and move perfectly smoothly when printed on my ultimaker2. However i'e got a reasonable number of comments from people complaining that parts are stiff or wont fit and i don't think its all down to cheap or poorly maintained printers.

someone told me slicing software directed the print head to follow the outline of digital model rather than work within the outline there for the outline of the actual print would be increased by the radeus of the nozzle.

Is this true and or dose it depend on the slicing software being used?

[IRobertI 521]

I can't speak for other slicers but cura works within the borders of the model. And I can't imagine other slicers do not, that would be silly.