2 Liter Bottle Cap Start

I tried to use eagleapex's 2 Liter bottle threads in Autodesk Inventor and got nowhere: http://www.thingiverse.com/thing:10489 I'm sure it's because I'm not using the program properly, or just because Autodesk doesn't like pulling in STLs.

So I measured it up and built a simple cylinder .5" tall with a 1/8" wall that has threads on the bottom half. I have included both the STL and the IPT so that if you are using Inventor you can also make random objects that attach to a 2 Liter Bottle.