Hey, Al. I do a lot of work in SketchUp and would be happy to help you if needed. By default, there is no Export STL option in the software and you will need to get the SketchUp STL plugin from the Extension Warehouse. If you are using 2016, once you install the plugin there are still a couple of steps to enable the Export STL option. Let me know if I can help you get on track with this.