Raptor Composite Aircraft

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pictsidhe

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What I see now, Peter is making some kind of brackets, to install "Push-Pull" cables, but how he will rout this cables trough airframe? This cables are much bigger in diameter that steel cables installed now and you can't bent them like this go around the rollers now. What he's thinking? With so many 90 degrees turns and small radius bends - ailerons would be even more "loose" with new cables and much "stiff" to control!
I'm not convinced that his new ailerons are going to work too well, either. One long cable per aileron, with multiple (3?) fairly tight bends. Let's see what Marc says. As someone commented weeks ago, all that friction should help with flutter!

Weight control? Yeah, that's probably the main reason I have redesigned so many parts of my project so many times. "I'm not fine with that'!
 

BoKu

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If he's adding the mass balance to the midline for flutter then it won't work.
It depends on the flutter modes and the stiffness of the elevator, stabilizer, and fuselage.

Plenty of airplanes (including my sailplane) have elevator mass balances at the plane of symmetry that work just fine. Usually those are there to mitigate flutter modes that couple the elevator mass with the resonant frequency of the fuselage. That's probably not a point of concern for Raptor, but I don't want people to think that no elevator counterweight at the POS can be effective.

--Bob K.
 

BoKu

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BoKu

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I'm not convinced that his new ailerons are going to work too well, either. One long cable per aileron, with multiple (3?) fairly tight bends. Let's see what Marc says. As someone commented weeks ago, all that friction should help with flutter!...
I could be wrong, but from the video it appears to me that he is planning on using a push-pull cable inside each wing, and a pair of sleeved pull-only cables inside the fuselage where the sleeves replace the four pulleys in the fuselage belly. If that is the case, he has a rude awakening in his future when he goes to tighten the cables to remove the slop.

At any reasonable cable tension, those sleeves are going to add so much friction the ailerons are going to be very hard to move. If he reduces the tension, it will increase the system slop. There might be a level of tension that is a reasonable compromise, but that won't last for long as the cable wears into the sleeve.
 
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Doggzilla

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Im not familiar with the types of cables and how they perform. What would you recommend?

And how does Malish use them? Maybe Peter can learn from Malish. The PJ is a good aircraft.
 

pictsidhe

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Marc's comment wasn't very clear to me. Since the test crew won't fly the Raptor if it has something they deem unsafe, I was curious as to whether the video solution was an 'appropriate implementation'.
 

Malish

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bmcj

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Keep in mind that a teleflex push-pull cable need not travel the entire cable run. He can add teleflex to get past the trouble areas and then transition to bellcranks and rods in the areas that have more structural stability. That way, the teleflex need not make multiple sharp bends.
 

PagoBay

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The FAA is promising relief from the 51% rule soon. (2years?) Could be up to 3000 pounds and four seats. I don't know if there will be a speed limit.
As promised by the FAA Acting Director at Theater in The Woods, Airventure 2019.
The weight increase and other possible changes are pertinent to Light Sport Aircraft in general.

The Major Portion rule is E-AB specific.

Can you quote what was said -- Specifically about the Major Portion 49/51 % rule?
 
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