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Post by Dennis on Aug 11, 2018 13:00:10 GMT -4
No, it does not want to!
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Post by krmckay "Bombs away" on Aug 11, 2018 13:49:43 GMT -4
So Dennis after all the testing today what's the plan now? These Hi speed taxi tests aren't producing any lift.
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Post by coyote on Aug 11, 2018 14:09:53 GMT -4
May be have Glenn or Jimmy look at it or an EDF or jet subject matter expert? With a weight of 22 lbs, and 14.5 lb thrust, she should lift.
It may be something obvious we're missing?
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Post by Dennis on Aug 11, 2018 19:15:15 GMT -4
So Dennis after all the testing today what's the plan now? These Hi speed taxi tests aren't producing any lift. Not really sure ,14 cell is an option but I'll need new esc,motor,lipos, and a bucket full of money to pay for it all
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Post by krmckay "Bombs away" on Aug 11, 2018 19:19:40 GMT -4
What if you slightly increased the diameter of the nose wheel to lift the nose and allow more air under the wing.
It would not allow you to raise the landing gear but might give you the angle of attack enough to break free from the ground on take off roll. Just a thought.
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glen
Instructor
Posts: 647
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Post by glen on Aug 12, 2018 16:15:08 GMT -4
How fast were the taxi speeds ? Kevin has a very good point, If you're racing down the runway with a negative pitch, it'll actually "stick" the airplane to the ground. That's the first thing I'd look at.
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Post by krmckay "Bombs away" on Aug 12, 2018 17:02:33 GMT -4
Glen,
The first take off tests over a week ago were way too slow you could tell just by watching. Dennis modified the intake and exhaust sizes and doubled his static thrust. Yesterday the attempted takeoff test was at least twice the speed and should have lifted off but full back on the elevator and it never broke free of the ground. This is why I'm suggesting changing the angle of attack while on the ground so as to get air under the main wing and provide lift, which should get the plane airborne. There is just nothing else I can think of or see why it should not fly.
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Post by Richard on Aug 12, 2018 18:30:59 GMT -4
Have you tried a takeoff with flaps down ?
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Post by Richard on Aug 12, 2018 18:45:54 GMT -4
I just watched a Ziroli F9F taking off with flaps partially down on YouTube. More lift !
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Post by Dennis on Aug 12, 2018 19:13:40 GMT -4
What if you slightly increased the diameter of the nose wheel to lift the nose and allow more air under the wing. It would not allow you to raise the landing gear but might give you the angle of attack enough to break free from the ground on take off roll. Just a thought.
Jet sits with positive angle as it sits now on gear.
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Post by Dennis on Aug 12, 2018 19:14:53 GMT -4
Have you tried a takeoff with flaps down ? Never tried flaps.
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ET
Silver Member
Posts: 64
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Post by ET on Aug 16, 2018 14:47:32 GMT -4
I agree with Ritchard, half flaps would not slow you down on takeoff and increase lift.
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Post by Richard on Aug 16, 2018 19:33:59 GMT -4
the full size F9F used half flaps on takeoff .
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Post by Dennis on Aug 19, 2018 16:47:12 GMT -4
the full size F9F used half flaps on takeoff . I guess this will be next , to test with half flaps.
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Post by Dennis on Jul 17, 2022 18:49:35 GMT -4
UPDATE Almost 4 years waiting to fly this, finally today with Al's help trimming and guidance and helpful tips from other flyers it took off and flew, aside from the landing(too fast) I'm extremely happy for this accomplishment . And thanks to Jack for video so I can watch and correct my flying.
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Post by krmckay "Bombs away" on Jul 17, 2022 19:17:45 GMT -4
Congrats Dennis. Great video...
Jack did you have a filter over the len as the sun didn't interfere with the video?
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