Hello,
Please see the attached.
This is my Big Red after changes to its aerodynamics in July 2021.
Change 1: addition of 2mm. carbon composite tube to the LE of the horizontal stabilizer. LE radius before (in 2019): 2.2 mm.
Change 2: addition of "wart" to the outside flap. Location and dimensions - from Igor Burger's Max Bee II plans
Change 3: increase of the area of the elevator by 8% (yellow extensions along the TE)
Changes 1 and 2 were suggested by Igor.
Krystian Borzecki, the best F2B flier in Poland, flew Big Red in August 2019 and told me: "this plane does not want to turn".
No further explanations were provided.
I have made about fifty patterns with Big Red until September 2019 but could not fix the "no turning" problem, whatever the root cause was.
At that time, I did not fully understand the hinging problem in sharp corners for the models having unequal wing panels and one propeller. Change 2 fixed this problem completely. Funny thing: I had Igor's plans but simply forgot to add "wart" in 2019. Consequently, for the entire 2019 flying season, I was flying the model that exhibited all sort of parasite yawing and rolling, associated with the eulerian movement of the rigid body in the 3D space when the sum of the moments is not zero.
Change 3 is my own initiative, based on my current understanding of the sharp corner dynamics.
Big Red flies very well now: there is no hinging, pivoting corners are executed with the audible "swish"and the parasite yawing and rolling disappeared. I managed to move the CG about 13 mm. aft. and this made the model very sensitive in the pitch channel. I can handle this increased sensitivity because my flying skills improved in 2020 and in the first half of 2021. Tracking and grooving are very good and I am quite pleased with everything I learned (and I am still learning) in the process.
Thank you to all who, on this forum, participated in discussion about hinging in sharp corners.
Happy Summer Flying!
Best Regards,
M