Mailtje teruggekregen van fvk:
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Hello Johan,
My name is Alex, I answer your mail to Jiri because my English is better than his and I tested the Plasma with a high power pylon setup (1.4kW, 35.000rpm, 5.25x6.25, 350kph propspeed, 900g).
Sorry for answering with a delay, but I was very busy the last weeks, this is not Jiri’s fault.
Your setup is extremely powerful; it will definitely bring the Plasma to its limits. Turning the 7x10 with 22.000 rpm will result in a maximum speed beyond 300kph. At this speed it is vitally important to fix the outer edge of the ailerons with adhesive tape otherwise you will definitely get fluttering. I’ve seen your pictures and it looks like your ailerons where not taped.
I believe that fluttering is the only reason that can cause such extreme forces that are necessary to break Plasma’s wing including the carbon connector in a straight and level flight. I’ve experienced it before with other models; it looks like the model simply explodes without any warning.
I don’t believe that a failure or a crack of material can be the reason. The crash would then happen during a turn. Even with lower speeds the aerodynamic force to the wing in a turn is much greater than in a fast level flight.
I hope I could help you finding the reasons for the crash.
I’m really sorry for your bad luck with Plasma. But with such an extreme setup you operate the model outside the spectrum for which it was developed. I’m very sorry we can not replace the damaged parts in this case.
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Dit is dus grote zever, mijn tipjes waren heel stevig vastgetaped.
Ik dit heb intussen al geleerd met hun sunracer en wou al van in het begin geen risico nemen, dus heb ik ze maar meteen getaped.
Ik heb ook op geen enkel moment flutter gehad.
Dit heb ik teruggemaild:
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Hello Alex;
The outside off my ailerons was fixed with tape just like I do with my sunracers !
I have several years of experience with high speed models and pylonracers and I can assure you there was no flutter at all when the wing broke down.
All the links were very tight , with zero tolerance and high power and precision Graupner DS 292 MG servos.
The prop was balanced and everything was running very smoothly and without any kind of vibration.
I am sorry to tell you that the airframe of the plasma is just no good, a thin profile on a very high speed plane can not be made in a two piece wing.
The small cfk rod in the middle can not thake the force wihout braking.
The sunracer from your company has a one piece wing and has never let me down.
best regards Johan