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Old May 22, 2012, 03:14 PM
MYC is offline
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Inconceivable!
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Now thats funny MadisonMaster! I do fly from the Nesaquake School fields on occasion but its a bit tighter there than out in Calverton (4250 Middle Country Rd Calverton NY) where I usually fly! I look forward to hearing about the nanotech packs tests...
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Old May 22, 2012, 05:15 PM
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Advice


Hey guys
I just maidened my F100 with CS 12 blade Het 700 68 1400, 8S.I noticed it would drop the nose in a turn, and it takes a fair bit of elevator to get it back. More power only exaggerates the prob.It is trimmed ok straight and level, CG is at 270mm.
Do you think it is still nose heavy? or is this a characteristic of swept back wings?
AUW approx 2.75KG( from memory)
Old May 22, 2012, 05:36 PM
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Make sure it is not rudder trim first by seeing if the nose drop happens in left and right turns. If not then CG may be the answer particularly if the elevator is insensitive.
Old May 22, 2012, 05:53 PM
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Originally Posted by twang View Post
Make sure it is not rudder trim first by seeing if the nose drop happens in left and right turns. If not then CG may be the answer particularly if the elevator is insensitive.
Hi Twang
Dont have rudder option at this stage, but this incident has convinced me to fit one.
steve
Old May 22, 2012, 06:05 PM
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Quote:
Originally Posted by heliclown View Post
Hey guys
I just maidened my F100 with CS 12 blade Het 700 68 1400, 8S.I noticed it would drop the nose in a turn, and it takes a fair bit of elevator to get it back. More power only exaggerates the prob.It is trimmed ok straight and level, CG is at 270mm.
Do you think it is still nose heavy? or is this a characteristic of swept back wings?
AUW approx 2.75KG( from memory)
At 280mm mine flies light on the elevator in turns (and it weighs 4kg).
Old May 22, 2012, 06:48 PM
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Originally Posted by heliclown View Post
Hi Twang
Dont have rudder option at this stage, but this incident has convinced me to fit one.
steve
Shouldn't have said rudder, more your fin may not be quite straight. Either way see if the nose drop happens in turns to the left and right. I see next post is using 280mm so maybe CG is the answer.
Old May 22, 2012, 10:49 PM
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Quote:
Originally Posted by heliclown View Post
Hey guys
I just maidened my F100 with CS 12 blade Het 700 68 1400, 8S.I noticed it would drop the nose in a turn, and it takes a fair bit of elevator to get it back. More power only exaggerates the prob.It is trimmed ok straight and level, CG is at 270mm.
Do you think it is still nose heavy? or is this a characteristic of swept back wings?
AUW approx 2.75KG( from memory)
I experienced the same characteristics with my CG at 265mm. Haven't had a chance to try a further aft CG but I'm planning on moving it back to 275 or 280 once I have a chance to install replacement blades.
Old May 23, 2012, 12:26 AM
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From what I can see ALL my planes drop a fair bit in banked turns. Which would seem totally normal to me... seeing your lift vector is moving well away from vertical and thus 'weakens' lift in the vertical direction dramatically then. And is of course why you need up elevator through turns too - whether the turn was aileron, or rudder, initiated/continued.
And if nose heavy it makes that worse, but even with good CofG it happens a lot anyway.
From P-51 to Mig-15 to Sport Jet.... all somewhat the same (P-51's seem quite bad at it), and as I mentioned.... seems totally normal to me.
If a plane did NOT fall through turns then that would be something amiss.

To maintain level flight through a turn you are pretty well feeding in elevator at nearly the exact same time as aileron and/or rudder. Pretty well in 'prediction', from experience, so that to an observer (or pilot) no "fall" was ever even seen to occur. Not turn/bank and then add elevator once you see fall is occurring. And some aircraft types need a bit more than others.
Old May 23, 2012, 01:08 AM
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You're right Peter, the airplane will descend, it should not however rotate in the yaw plane (ie rotate nose toward the ground) when in the turn. It will lose height but to a point the attitude shouldn't change.
Old May 23, 2012, 01:57 AM
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I'll have to pay more specific attention to the "banking drop" next time, LOL.
I can't really remember, but I can picture it 'yawing down' too. And would expect it to (thinking about it). Though, what amount is normal or not....

If you did nothing to correct it, it would just go more and more towards vertical (ultimately). So to get to that it had to yaw. A slower 'linear' yaw, or a more sudden dramatic one that goes beyond 'linear'? I guess that would depend on the amount of turn radius and banking, and the aircraft wing design too. All aircraft could be 'corrected' (elevator) - whether real-time, or after the fact - but how much you need, or how soon etc, could vary.

If a fin was mis-aligned, even by a small amount, you will know pretty soon! And would have trimmed it out too, whether correctly with rudder, or incorrectly with aileron. But you should have recognised a specific direction issue quite soon, and thus would associate further 'odd' flight moves to that, as applicable.
So I don't think it is that.

I think it sounds more like it is notably nose heavy.....
And some aircraft are probably more sensitive to that than others too - thus a more dramatic result of its influences/consequences.
Old May 23, 2012, 05:24 AM
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4Stripes


Hey Mate
How did you achieve 280mm Cg?,Did you remove some foam at the back of the battery compartment?. My Lipos are as far back as they go,at present,so i would need to cut away more foam at the back.But i will add (temporarily) 130gm lead in the tail, to achieve 280mm cg, and give it a go.
I stuffed up on the AUW also, it is really 3.75 KG, not 2.75(so much for the memory).
I cant get over how quiet the fan is!I am impressed!
Old May 23, 2012, 06:46 AM
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WHO's your DADDY!!!
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Heliclown you didn't happen to take any video did ya? I'm curious to hear the 12 blade in this airframe or even the F86, I have both and am considering a fan upgrade
Old May 23, 2012, 07:45 AM
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Quote:
Originally Posted by heliclown View Post
Hey Mate
How did you achieve 280mm Cg?,Did you remove some foam at the back of the battery compartment?. My Lipos are as far back as they go,at present,so i would need to cut away more foam at the back.But i will add (temporarily) 130gm lead in the tail, to achieve 280mm cg, and give it a go.
I stuffed up on the AUW also, it is really 3.75 KG, not 2.75(so much for the memory).
I cant get over how quiet the fan is!I am impressed!
My battery is also all the way back. My fan/motor is pretty heavy at 500g because of the Turnigy XK4074-B-1400. With 6s mine flies at 280mm CG and with my extra 1S pack added for 7S it moves forward a little (the amount of elevator needed for any maneuvers is noticeably more).
Old May 23, 2012, 04:16 PM
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Originally Posted by 4stripes View Post
My battery is also all the way back. My fan/motor is pretty heavy at 500g because of the Turnigy XK4074-B-1400. With 6s mine flies at 280mm CG and with my extra 1S pack added for 7S it moves forward a little (the amount of elevator needed for any maneuvers is noticeably more).
thx for the info, Another thought, I flew with the large inboard wing tanks.This would add to the drag no doubt,coupled with the fact that this thing is so quiet,maybe i am simply flying(turning) with too low a power setting for this config?

JCB
Sorry mate, too busy trying not to crash at this stage,and hard to get camera man at 6am and 1 degree C. LOL
Old May 23, 2012, 04:18 PM
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Jbc


Sorry JBC, for getting your name wrong!!


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