ORIGINAL: BMatthews
A couple of the old designs had some really crazy amounts of downthrust specified. The gull winged one by Ontario Modelcraft is one but the name of the model elludes me at the moment. A flying buddy has built a few of them and they all needed a silly amount of downthrust.
Also the closer the engine to the balance point the bigger the angle has to be to achieve the desired effect. The ones that need this the most are also the ones with the power axis located well below the wing, which forms the lion's share of the overall drag of course.
The further the thrust POINT from the wing - the more the moment arm for thrust becomes
this is the REAL problem - just like a old rc trainer with a very high wing location and a very low thrust line
sam ting.
This is a bult in loop setup - th so called excessive thrust simply was an attempt to circumvent this problem
The fast fix is to move the thrust line up -
I know -that spoils the old timer setup
You can't have your Kate and Edith too.