Hey folks,
From time to time on the forum, someone asks how to trim these models for flight. This video link to Youtube shows the basic premise for the downthrust shim.
http://www.youtube.com/watch?v=RUqtrIC2J2k
He doesn't mention it in this video but, I think this is the flight with the downthrust shim.
http://www.youtube.com/watch?v=iDy8UqzRNB8