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RE: Flaperons? - 4/22/2012 4:47 PM   
eddieC



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Only fix one problem at a time. The most obvious is the CG issue. After you fix that fly it and see how it fly's. You will have other adjustments to make after that, such as elevator throw and trim. If you change more than one thing at a time you will be chasing problems until you eventually get it all balled up.   


Cfircav8r's comments are spot on. Fix one thing at a time, in this case CG, then test.

Is it me, or are rctech's posts challenging to read?  It's like I'm decoding a puzzle, and the diagrams were way too much info. 

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RE: Flaperons? - 4/22/2012 5:30 PM   
combatpigg



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ORIGINAL: cfircav8r

CG will not effect the stall other than increase (nose heavy) or decrease (less nose heavy) the speed at which it stalls. How it stalls is controlled by wing design and pilot inputs.

Edit: this was not directed at you Speed I forgot to hit the reply button.


A CG that is too far forward will make the plane behave like it is heavier than what it really is.
The OP should take note of his elevator trim for level flight after he lands it. If he has a bunch of UP elevator dialed in, he needs to shift the weight aft.


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RE: Flaperons? - 4/22/2012 7:41 PM   
Aviator 25


 

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Status: offline 		Well I think what we have here is everyone here all being a little right about my problem.
1. The CG not being right. (The plane's CG was quite far out and this is not good at all, I should have know better then to just fly it with out properly checking the CG).
2. The plane is going to land different then before. (I need some time getting to know this all new setup, if only this weather would give me a chance!).
3. The engine has a LOT more power then before! (Just touching the throttle stick makes this plane jump making it hard to land under power).
4. The plane is heaver now affecting stall speed. (this is true and not much I can do about it....or can I?).
5. Spoilerons and flaperons, the reason I posted here. (Going back to above problem 4. I was wondering if there was a way to cheat using spoilerons or flaperons to shorten the planes landing distance, after all I have all this computer crap on my radio to use at my disposal).

The weather is not agreable so I have spent my time tinkering with the plane. I have moved the CG back a bit more (I don't see why I should be having to add up elevator trim to fly this plane). I have also programed 15 degree spolerons into my radio as well as 5 degrees of flaperons. I don't know if any of these will help shorten landings. Any ideas?




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RE: Flaperons? - 4/22/2012 8:13 PM   
combatpigg



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Status: offline 		Make sure you haven't left any tools [like a socket set or anything similar] inside the plane.
I've flown a few planes in the 700 sq inch size range and the heaviest might have been around 7 pounds with 5 servos, a AA cell battery pack and .60 sized engine.


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RE: Flaperons? - 4/22/2012 10:26 PM   
BFoote


 

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quote:

ORIGINAL: cfircav8r

CG talk is garbage? So you don't balance your planes? If it were garbage then why would ''real computer controlled airplanes'' require the CG to be within a specified range. That would be because too far forward and you loose tail authority (yes I know you said that), but too far aft you loose pitch stability, such that even a computer can't compensate. Long range aircraft generally keep the CG more aft during cruise to noticeably increase range (amazing how such a small change in load can help so much.) I am saying fine tune your airplane, sure you can fly almost anything if its kinda close on balance, incidence, and weight, but don't they fly so much nicer when it is adjusted to normal ranges. What Speed and I are advising will benefit the performance throughout the envelope, not just on landing. If after tweaking it a little he still feels it has bad tendencies then by all means he should try some reflex. If you choose to fly a TLAR airplane be my guest, but not everybody is willing to accept mediocre on an A/C that is made to perform, and without the fine tuning adding reflex is a second rate fix on what is supposed to be a first rate A/C.


Does everyone take a comment to the extreme?

Its the internet baby!

Guess I should expect nothing less.

Its rather humorous, all I did was pretty much quote what you said combined with what BMatthews said on the 1st page of this discussion till the definition shavers got involved whereupon you descended to their level.

CG @ MAC for most everyone's plane: Since you believe everyone on the internet is an idiot besides you.
Depends on NP, VTAC, VHTAC, how many other terms do you want thrown in there? Does anyone on this forum actually know these numbers for their model? No. So, generalities is the name of the game. The OP wanted to get his plane down without stalling his main wing, at which point CG of the plane matters not one damn unless its insanely far forward, as long as you have enough tail authority over the A/C's velocity profile. Thus its back to Spoilerons discussion.

Trainer: 25%
Pattern flyer 30% or wherever their plane is neutral for their airspeed stunt speeds pick your poison, loops, hammerheads, etc
Heavy Lift 35%

Now, why the heck did I waste my time typing this?
Guess I am the stupid one.



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RE: Flaperons? - 4/23/2012 5:58 PM   
BMatthews



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Status: offline 		Gentlemen, would some of you talk this way if you were face to face over a beer? I suspect not. Please consider that if someone misunderstands something you type that it may well be due to the nature of how discussion forums work and try to be polite and respectful in correcting them. Similary if you feel you found a glaring error in someone's post try reading it again with a more open mind. It's likely they made some sort of assumption based on a previous post or missed out including some important detail. Don't use it as an opportunity to leap on their post. Instead ask for clarification. Doing so makes things a lot less heated and results in less deleted posts.

It's been my experience that often the worst posting enemies would be great friends if they only discussed things over a beer. Try to look at forums such as this as the same venue.

This post applies to many throughout this thread and only the last few.

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RE: Flaperons? - 4/24/2012 2:36 AM   
rctech2k7



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Status: offline 		With that post even if you don't see the person, it makes him look professional, mature and therefore more respected...

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RE: Flaperons? - 4/24/2012 2:40 AM   
rctech2k7



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Status: offline 		cfircav8r, BFoote just want to support your statement that it's all depends on the aircraft... as the CG can be compensated by many factors...


EddieC - you know better than what I have posted.


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RE: Flaperons? - 4/24/2012 2:51 AM   
rctech2k7



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Status: offline 		Aviator 25 - I don't suggest to move the CG more back then applying spoileron. Spoilerons are better for slightly nose heavy as per your OP...

If you move the CG more back it will makes more difficult to land. Most likely worse on windy. You've experienced to stall when you move your CG back and if you activate spoilerons you would stall more. Flaps would help you to increase lift but it will reduce your authority to your plane. Spoilerons may not be applicable anymore with your present CG but I may be wrong when you determine some parameters including MAC of your plane.

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RE: Flaperons? - 4/24/2012 8:40 PM   
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Status: offline 		Well my plane is coming in hot using up all the runway so what I'm thinking about is using spoilerons just before the plane touches down to get it down and make it stay down so it does not keep bouncing down the runway until it runs out. Maybe the drag will also slow the plane down after it lands.

By the way I'm still waiting on the weather, the wind just keeps blowing and blowing.

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RE: Flaperons? - 4/24/2012 10:08 PM   
eddieC



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Status: offline 		How does it slow-fly at altitude, any bad habits? Have you moved the CG back and tried it? We've been having lots of winds for the last week, so it's understandable if you haven't been out.

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RE: Flaperons? - 4/25/2012 2:58 AM   
Aviator 25


 

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Status: offline 		Well I've not had much time to get much flying in because of weather but I did at one point try a little hovering on its tail on one of the last flights I did and it seemed like it was doing good, though I only tryed it quickly. I'm still getting used to this new setup and I didn't want to push my luck. But next time I fly I'm planing on trying some slow flight to see how it acts.

WIND WIND GO AWAY!!!

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RE: Flaperons? - 4/26/2012 4:42 AM   
rctech2k7



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quote:

ORIGINAL: Aviator 25

Well my plane is coming in hot using up all the runway so what I'm thinking about is using spoilerons just before the plane touches down to get it down and make it stay down so it does not keep bouncing down the runway until it runs out. Maybe the drag will also slow the plane down after it lands.

By the way I'm still waiting on the weather, the wind just keeps blowing and blowing.


That's a good idea but spoilerons will makes you to descend faster. Last time when you were nose heavy your plane won't land due to more lift and since you've feel great with flying that's why we recommend to add spoilers to increase descend rate as you can see from our earlier post. How come now your plane has lesser lift when you move your CG back? Should be lighter or you're probably using same landing style as you were nose heavy before. If you are comfortable and more advantage with your present CG leave it as it is otherwise if you want to descend smoother and slow, move your CG forward and raise your AOA and with power on landing but if you gain more lift then you can use spoilerons. You can probably change in between where you can avoid using spoilerons, as well as being too nose heavy. But at this time because of the new nature of your plane I discourage you to use spoilerons. You can use slight flaperons would be better to slows down rather than using spoilerons at this time. With your flaps you can reduce AOA but still have lift. Spoilerons is applicable to increase your descend rate but not to lower your speed. However in some way it slows down the aircraft by increasing your AOA as spoilerons increases your stall angle and it creates pitch up moment depending on the nature of an aircraft and stability. It also use to increase authority by increasing speed.

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RE: Flaperons? - 4/27/2012 2:25 AM   
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Status: offline 		Ok, I finally got out to fly last night and the results are in. Take off was good with no problems and the plane flew great, it didn't even need any elevator trim. I tryed some slow flying and the plane had GREAT maneuverability (I think even better than at higher speeds). I did some landing approaches and the plane seemed to behave better and at slower speed. I decided to get some altitude and try out the flaperons so I slowed down and set it with only 5 degrees. The plane start to increase lift and rise at a level attitude, no elevator input was needed. I tryed some slow flight like this and the plane flew much slower with out stalling so I decided to try a landing approach. The plane came in so nice that I could not help but land and it slowly touched down on all 3 points. The plane rolled about 8 feet in total, it was perfect! I didn't get time to try spoilerons but maybe another day. It looks like we have finally nip this problem in the bud.

Thanks guys!

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RE: Flaperons? - 4/27/2012 2:48 AM   
eddieC



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quote:

I decided to get some altitude and try out the flaperons so I slowed down and set it with only 5 degrees. The plane start to increase lift and rise at a level attitude, no elevator input was needed


Sounds like you experienced some 'ballooning', which is to be expected. You could try spoilerons next, but it will have the opposite effect; will cause a descent, and you'll probably need some up-trim or carry some elevator.  Sounds spot-on the way it is. How much of a CG change was it?
Good job ! 

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RE: Flaperons? - 4/27/2012 3:40 AM   
speedracerntrixie


 

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Status: offline 		Aviator, glad you are getting good results. I want to thank you for following through with moving the CG back and reporting the results. I knew it would lead to overall better performance.


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RE: Flaperons? - 4/28/2012 2:36 AM   
rctech2k7



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Status: offline 		Aviator 25 - you've made it, 5-deg is good enough for slight lift differential with negligible drag. Flaperons produce wing camber which increase lift but may cause nose down effect... Your plane overcome that changes in moment, so it means you have made a perfect balance of CG, AOA and airspeed combination. Supposed to be surface extended produce an added stability other than prone to wind strike in some condition but your aircraft seems already gained stability as you've mentioned on your high speed. If you have that spoilerons may not affect any change in moment other than lift reduction which we are expected. As per as eddieC post, just be ready for those tendency when you test that.

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RE: Flaperons? - 4/28/2012 5:09 PM   
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Status: offline 		eddieC the CG was moved from 4.125" to 4.25".
I think this engine's weight just had such a huge effect on this plane that the original manufacturer's CG recommendation would not work. After all the plane was never really designed with the DLE 20 in mind.

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RE: Flaperons? - 4/28/2012 5:38 PM   
rctech2k7



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Status: offline 		Good result, so the flaperons is the one that probably compensate for the CG and vise versa. It's my mistake to expect an increase in stability during normal flight but actually the feel softness of an aicraft that what it feels great on higher speed not being solid because of the resistance of an aicraft to follow changes... If you don't mind, do you know where it falls based on MAC of your aircraft?

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RE: Flaperons? - 4/28/2012 6:30 PM   
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Status: offline 		rctech2k7 I think the Mean Aerodynamic Chord is around 13" over from the wing root and that puts the CG at that point around 3.625" from the LE.

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RE: Flaperons? - 4/28/2012 10:25 PM   
rctech2k7



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Status: offline 		Thank you for your prompt respond. That's 28% which is almost close to 30% of MAC. BFoote is correct for specifying 30% on this category. Even if speedracerntrixie didn't mention anything about his expertise it proves that you can trust this guy with regards to this aircraft. With no doubt, this aircraft can land on negative stability. The manufacturer is quite conservative for specifying the safe CG location. This is how I wonder that speedracerntrixie is landing this aircraft w/o elevator. On overall, it's you who feel the differences who made a correct decision for deriving solution.

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RE: Flaperons? - 5/3/2012 6:16 PM   
Aviator 25


 

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Status: offline 		Well.... Thanks guys for all the help, but all for not, The extra is no more. There was a radio malfunction and the only one flying the plane was physics and God, both decided the plane should meet the ground at 3/4 throttle. Not much left of the plane.

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RE: Flaperons? - 5/3/2012 7:08 PM   
eddieC



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Status: offline 		Ow, I hate when that happens! 

Upgrade opportunity? 

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RE: Flaperons? - 5/4/2012 9:38 PM   
rctech2k7



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Status: offline 		Sad to hear that... What happened, did it went into fail-safe? How was your onboard equipments?

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RE: Flaperons? - 5/4/2012 11:44 PM   
BFoote


 

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quote:

ORIGINAL: Aviator 25

Well.... Thanks guys for all the help, but all for not, The extra is no more. There was a radio malfunction and the only one flying the plane was physics and God, both decided the plane should meet the ground at 3/4 throttle. Not much left of the plane.


UG, I am sorry. I have had one plane do this to me and my brother also. My brother made a beautiful biplane and it went straight in from 200 feet on its 3rd flight. It destroyed Everything, even the engine.

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