Hi guys,
I've build and flew the RetroM prototype from those videos you are reffering to, so I think It worths to share some feed-back on this.
First of all, I don't speak german, so I have to relly on Google translate, altough is quite difficult because of so many technical terms :-).
Anyway, my understanding is that you are wondering if there is some risk of surfaces fluttering or fuselage/ wings torsion at high speeds; even if the fuselage of the prototype was made of fiberglass, not airrex as the production version, so supossely not so stiff, I didn't notice any torsion or flutter in flight.
The elevator had indeed some play from the linkage connection ( I did not used a ball link joint, it was only a steel wire creted a small play in the control horn), so it might be possible that the pitch movement you've notice in video to have something to do with that.
I only used one rate in those flights, with the following control throw settings/ rates:
- aileron: 23 degrees up/ down, exp 40%
- elevator: 15 degrees up/down, exp 30%
- rudder: 20 degrees left/right, exp 30%
- flaps: take off/ landing, 37 degrees down, mix with down elevator 12%
The Center of Gravity was at 143mm from LE of wing at fuselage
No other mix/ ail differential was uses.
I ussually fly 3D airplanes, but I fell in love with the design the first time I saw it at Mugu, so RetroM became my first jet/edf airplane :-). I'm sure you guys have a lot more experience with jets/ edf to get the best out of this beautiful airplane, so I'm equally following Heiner building/ flight report.
Regards,
Andu