Lego Parts in Inventor

[7-11number1]

Hi this is team 1711. This coming season will only be our 3rd year in FIRST so we trying more at becoming a more organized team and give students more hands on experience in the build. One idea was to give students lego mind storm in a tech class and follow that with having the students go on computers and create 3d models of their robots in Inventor.
Our problem is that we do not have any lego parts in .ipt files to use. I have searched online and found lego building programs but that will not work because we are using school computers, so my only option is to take every lego we have and create a library of dozens of parts.
I was hoping some one would know if we could buy a package online that would have the pre-built lego files, and if not just some good inventor tips for organizing and creating such a large number of parts.