Create own model by sketchup

I want to export one file of ketchup, but it doesn’t work.
what do I have to do?
Export in *.stl doesn’t work… “file don’t exist”…
whats the best way to create an own model?

In Sketchup, go to Window/Extension Warehouse, then search for Sketchup STL. The first result should take you to this page:

Because you loaded it from within Sketchup, it’s a breeze to install.

I’ve been exporting Selected Only as STL (ASCII) in MM for the Zim.

Then I open the part in Netfabb Basic and check for errors. It’s complicated enough were I should probably make a simple tutorial video of the error fixing part, but here’s some initial help: