How to retrieve an Inventor drawing without the software

I designed a CNC machine completely with every detail while working at my old job using Inventor. At my new job, I only have the AutoCAD package. I still have the CNC machine files saved on a drive, but I cannot afford to purchase Inventor, and my new employer will not because we don't need it here. I need a way to retrieve those parts and assemblies so I can finish the build and do not know how. I know there is a way to convert it IF you have Inventor, but I don't know if getting the 30 day trial will allow me to or if there is another way or free software that will assist me.