Stl's always load sideways into slic3r

I am trying to load stl’s to slic3r and they come out on the side and I can not figure how to rotate them. I am using inventor and have tried rotating and saving but I am sure I am missing something minor here. Anyone else run into this problem

I generate mine with Inventor. Basically you need to ensure that the X and Y plane arrows are at the bottom of the part, and the Z arrow is pointing up in the design view. If you can’t flip them in inventor, download the free version of netfabb, it has a really easy STL flipper, as well as a “repair wierdness that Inventor sometimes makes” button.