Update:Cannot get wings to stop rocking!!
08-01-2006 | 02:09 PM
#26
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RE: Cannot get wings to stop rocking!!
ORIGINAL: FalconWings
I use IPACS Aerofly Deluxe and to date I haven't seen a model as difficult to Harrier as my Yak.
I use IPACS Aerofly Deluxe and to date I haven't seen a model as difficult to Harrier as my Yak.
08-01-2006 | 04:26 PM
#29
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RE: Cannot get wings to stop rocking!!
Regarding the differences in harrier between a Cap and a Yak. The 232 is the plane that all others have come to be judged by when it comes to a harrier. With the exception of a really big Yak I have not seen a plane to date that does it better. The Extras are pretty good at it, but generally perform the maneuver better if inverted. The position of the empennage in relation to the main wing is everything in a harrier. Many models pay close attention to the general appearance of the full scale plane, but miss the tail relationship completely. That will leave you with a plane that looks generally right, but is off the mark in performance. As noted in another post, weight and wing loading bear significantly in the final performance too.
On to props, my opinion is that an 8 pitch prop would be better. I'm one that believes that too many people are over propping the DA 50 and unknowingly suffering a loss in all around performance for doing so. It's a "well he's doing it so I'm going to do it" herd instinct type of thing. You may benefit with the greater pitch in one area, but suffer in many others because of it.
On to props, my opinion is that an 8 pitch prop would be better. I'm one that believes that too many people are over propping the DA 50 and unknowingly suffering a loss in all around performance for doing so. It's a "well he's doing it so I'm going to do it" herd instinct type of thing. You may benefit with the greater pitch in one area, but suffer in many others because of it.
08-01-2006 | 04:44 PM
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RE: Cannot get wings to stop rocking!!
No catch. 
But if you blip it a lot you get more torque forces setting the rocking off. How does it do in elevator? If your elevators are stabile, it will harrier aswell.
But if you blip it a lot you get more torque forces setting the rocking off. How does it do in elevator? If your elevators are stabile, it will harrier aswell.
08-01-2006 | 05:08 PM
#31
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RE: Cannot get wings to stop rocking!!
Lateral balance will effect harriers even if the plane is in trim. I am not saying it is the problem, but per your symptoms it very well could be. Its not uncommon for a plane that is out of lateral balance to fly very well with virtually no trim adjustments, but when you pull hard on the elevator you accentuate the problem . Tor asked a good question. How does your plane do in an elevator maneuver? If it rocks in a harrier it should REALLY rock in an elevator.
Is the plane noseheavy?
How much does the plane weigh?
Is the plane noseheavy?
How much does the plane weigh?
08-01-2006 | 05:59 PM
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RE: Cannot get wings to stop rocking!!
All the above posts give great advice..sometimes however it is just the way the plane is designed..You could have 2 Extras from 2 different designer's and maybe one guy stretched the tail a little or has the stab in a different location etc..On my WH Edge I balanced laterally, moved the CG around, reduced the weight..basically tried all the suggestions that everyone has given..Still had the rocking..I learned how to get rid of 80% of it but it takes a lot of minor corrections to keep it smooth..It can be done..it just takes some effort..BTW WH has re-designed the Edge to help with the rocking wings..I think the stab has been moved forward but Im not 100% sure..
OTOH, my EF 87" Yak has ZERO rocking at 45 deg 50..65 etc.. the only time the wings wobble is in a crosswind and even then it only takes minor rudder or aileron to stop it..
OTOH, my EF 87" Yak has ZERO rocking at 45 deg 50..65 etc.. the only time the wings wobble is in a crosswind and even then it only takes minor rudder or aileron to stop it..
08-02-2006 | 08:49 AM
#33
RE: Cannot get wings to stop rocking!!
I will give it a try on lateral balance. Mymodel is aorund 16~17lbs, which is pretty light for it's size. It is 87" wingspan. My Cap was 80" and weighed the same. It is balanced on the tail heavy side. The manufacturer recomends 5~6" CG point. I'm balancing more at like 7", which is great for many maneuvers.
What is an elevator? I may have done it but not know the name. Isn't that a decending Harrier? If so, Yes I've done it and yes it rocks the same side to side.
Now to the pulling deal. I do not start a Harrier with a hard pull from straight and level flight. I typically decend two mistakes high, go to idle and when the model is about to break I give it 2~3 clicks of throttle and snap roll (the model will decend). Then when I stop the snap roll I'm already at 75% or so elevator and ready to Harrier. Looks a lot better than yanking it into submission.
But I haven't been doing his lately because of the rocking issue.
David
What is an elevator? I may have done it but not know the name. Isn't that a decending Harrier? If so, Yes I've done it and yes it rocks the same side to side.
Now to the pulling deal. I do not start a Harrier with a hard pull from straight and level flight. I typically decend two mistakes high, go to idle and when the model is about to break I give it 2~3 clicks of throttle and snap roll (the model will decend). Then when I stop the snap roll I'm already at 75% or so elevator and ready to Harrier. Looks a lot better than yanking it into submission.
But I haven't been doing his lately because of the rocking issue.
David
08-02-2006 | 10:53 AM
#34
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RE: Cannot get wings to stop rocking!!
OK, some thoughts....The first thing I would try is an inverted harrier. If your wings do not rock in an inverted harrier, then I suspect that the wing incidence is off a bit. It sounds like the wing is effecting the prop blast over the V-tail at high alpha. When performing an upright harrier, the V-tail isn't getting enough airflow. Of course, if your wing incidence gets moved more negative, then you will be able to moveyour cg back without changing the tail incidence...hopefully! This should allow more airflow over the lower portion of the rudder (fat portion). From what I have read here, I agree with you that it is a high alpha lateral stability problem. I'll bet you don't have this problem inverted because there is so much V-tail above the thrustline.
08-02-2006 | 11:06 AM
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From: Copenhagen, DENMARK
RE: Cannot get wings to stop rocking!!
Yes elevator is a power off, decending harrier.
The pulling thing just shows you if it's off balance, it doesn't matter how you enter the harrier - if it's off balance, it will rock, depending how big the imbalance is.
On another note, too tailheavy is not necesarily a good thing. It may destabilize everything, try to move the CG forward to what the manufactor recommends.
Check the lateral balance, move the CG forward and maybe lower your throws on the elevator if they are really high. I my experience, it doesn't work to go crazy on the throws on larger models. Thought I don't know your model , I would say 40 - 45 degs is sufficient, more throw will destabilize things too. Personal theory is that you want the elevators to work (airflow, renoylds numbers on larger models etc.) rather than acting as brakes.
I know that moving CG forward and lowering throw may go against other people's normal advice... But as the saying go "too much of a good thing..."
The pulling thing just shows you if it's off balance, it doesn't matter how you enter the harrier - if it's off balance, it will rock, depending how big the imbalance is.
On another note, too tailheavy is not necesarily a good thing. It may destabilize everything, try to move the CG forward to what the manufactor recommends.
Check the lateral balance, move the CG forward and maybe lower your throws on the elevator if they are really high. I my experience, it doesn't work to go crazy on the throws on larger models. Thought I don't know your model , I would say 40 - 45 degs is sufficient, more throw will destabilize things too. Personal theory is that you want the elevators to work (airflow, renoylds numbers on larger models etc.) rather than acting as brakes.
I know that moving CG forward and lowering throw may go against other people's normal advice... But as the saying go "too much of a good thing..."
08-02-2006 | 04:26 PM
#36
My Feedback: (3)
RE: Cannot get wings to stop rocking!!
ORIGINAL: Tor
Yes elevator is a power off, decending harrier.
The pulling thing just shows you if it's off balance, it doesn't matter how you enter the harrier - if it's off balance, it will rock, depending how big the imbalance is.
On another note, too tailheavy is not necesarily a good thing. It may destabilize everything, try to move the CG forward to what the manufactor recommends.
Check the lateral balance, move the CG forward and maybe lower your throws on the elevator if they are really high. I my experience, it doesn't work to go crazy on the throws on larger models. Thought I don't know your model , I would say 40 - 45 degs is sufficient, more throw will destabilize things too. Personal theory is that you want the elevators to work (airflow, renoylds numbers on larger models etc.) rather than acting as brakes.
I know that moving CG forward and lowering throw may go against other people's normal advice... But as the saying go "too much of a good thing..."
Yes elevator is a power off, decending harrier.
The pulling thing just shows you if it's off balance, it doesn't matter how you enter the harrier - if it's off balance, it will rock, depending how big the imbalance is.
On another note, too tailheavy is not necesarily a good thing. It may destabilize everything, try to move the CG forward to what the manufactor recommends.
Check the lateral balance, move the CG forward and maybe lower your throws on the elevator if they are really high. I my experience, it doesn't work to go crazy on the throws on larger models. Thought I don't know your model , I would say 40 - 45 degs is sufficient, more throw will destabilize things too. Personal theory is that you want the elevators to work (airflow, renoylds numbers on larger models etc.) rather than acting as brakes.
I know that moving CG forward and lowering throw may go against other people's normal advice... But as the saying go "too much of a good thing..."
08-08-2006 | 01:19 AM
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RE: Cannot get wings to stop rocking!!
Something that nobody has mentioned yet, at least I don't recall reading it in the htread so excuse me if it has already been mentioned....
Seal the gaps on the control surfaces. I have found that for small models, by that I mean ANYTHING under 35%, this really can help a grat immensely. I don't care how tight your gaps are the airflow through the ailerons will differ on either side and hence they are not operating in a balanced state. This same rule applies the elevator halves as well, just do it if you haven't already, you might be surprised at the results.
The lateral balance is crucial and if you have a heavy wing it will start the rocking process every time you pull the nose up and slow down.
As NEAR to perfect symetrical elevator throws as can be acheived on dual elevator servo equipped planes is a must. Make 2 pointers from a pair of clothespins and carbon rods that are about 12 inches long and clip them on the elevators. Next cycle the elevators up and down and observe the pointers, do they track each other to within an 1/8th of an inch of each other throughout the arc from full up to full down throw? If they don't fix it so they do.
Is the model touchy in a hover in calm air? If so you probably have too much throw or too little expo. If your chasing the plane to keep the nose up and in one place you need to work on getting it stable in a hover where small, quick corrections are all that is needed to hold a steady position. My rule is if you are fighting the plane in a hover you will fight it in other maneuvers as well, like harriers, especially harriers.
Too much expo, this will get you every time. I have found that the less the better, but you still will NEED some to be able to smoothly control and correct small errors. The problem is, if you use too much you will always be behind the plane every time you attempt a correction. If you use to little your corrections will have to be almost perfectly timed and executed. So how much is too much expo? I've found that most planes are happy with between -20 and -30(Futaba or Hitec) on the rudder and about the same on the elevator, sometimes a bit more but never more than -35. It seems that once you start cranking in more than -35 the controls it's extremely difficult to maintain any feel for the plane as the controls become far too soft. Sure I know some guys that can fly this way and I know just as many that use no expo at all....most of us are not goine to be successful if we try flying in either of these categories IMO.
Servo blow back can also be an issue that many might neglect to check for. Make sure your controls are maximizing servo power and resolution. I can't recall the number of times that I helped a guy out at the field or on-line by telling them to move their clevises all the way out on their horns and in some on their servo arms and then fly the plane. Without fail they noticed a big improvement in control response immediately even though their control throws were sometimes cut nearly in half. It's my humble opinion that more guys get into trouble by worrying about having big throws than any other single issue, all of my planes use about 30 degrees on the rudder and elevators and will do whatever I want, ailerons are a matter of personal preference so set them up for a roll rate that doesn't give you a headache and fly it.
Seal the gaps on the control surfaces. I have found that for small models, by that I mean ANYTHING under 35%, this really can help a grat immensely. I don't care how tight your gaps are the airflow through the ailerons will differ on either side and hence they are not operating in a balanced state. This same rule applies the elevator halves as well, just do it if you haven't already, you might be surprised at the results.
The lateral balance is crucial and if you have a heavy wing it will start the rocking process every time you pull the nose up and slow down.
As NEAR to perfect symetrical elevator throws as can be acheived on dual elevator servo equipped planes is a must. Make 2 pointers from a pair of clothespins and carbon rods that are about 12 inches long and clip them on the elevators. Next cycle the elevators up and down and observe the pointers, do they track each other to within an 1/8th of an inch of each other throughout the arc from full up to full down throw? If they don't fix it so they do.
Is the model touchy in a hover in calm air? If so you probably have too much throw or too little expo. If your chasing the plane to keep the nose up and in one place you need to work on getting it stable in a hover where small, quick corrections are all that is needed to hold a steady position. My rule is if you are fighting the plane in a hover you will fight it in other maneuvers as well, like harriers, especially harriers.
Too much expo, this will get you every time. I have found that the less the better, but you still will NEED some to be able to smoothly control and correct small errors. The problem is, if you use too much you will always be behind the plane every time you attempt a correction. If you use to little your corrections will have to be almost perfectly timed and executed. So how much is too much expo? I've found that most planes are happy with between -20 and -30(Futaba or Hitec) on the rudder and about the same on the elevator, sometimes a bit more but never more than -35. It seems that once you start cranking in more than -35 the controls it's extremely difficult to maintain any feel for the plane as the controls become far too soft. Sure I know some guys that can fly this way and I know just as many that use no expo at all....most of us are not goine to be successful if we try flying in either of these categories IMO.
Servo blow back can also be an issue that many might neglect to check for. Make sure your controls are maximizing servo power and resolution. I can't recall the number of times that I helped a guy out at the field or on-line by telling them to move their clevises all the way out on their horns and in some on their servo arms and then fly the plane. Without fail they noticed a big improvement in control response immediately even though their control throws were sometimes cut nearly in half. It's my humble opinion that more guys get into trouble by worrying about having big throws than any other single issue, all of my planes use about 30 degrees on the rudder and elevators and will do whatever I want, ailerons are a matter of personal preference so set them up for a roll rate that doesn't give you a headache and fly it.
08-08-2006 | 08:33 AM
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RE: Cannot get wings to stop rocking!!
Nice post, Scott. I find the too much expo makes me feel like i always want to grab another handful, if you know what I mean. The gap sealing thing is new to this thread. I find I can get away with less throw than you'd think, especially with larger models. On my smaller ones I make sure 3D mode has those extreme throws. Interestingly, though, I often prefer hovering and doing TR's in normal mode. At this level it shouldn't be about saving a mistake, or getting out of trouble. If that's where the pilot's at the move is going to be a mess no matter what.
08-08-2006 | 08:49 AM
#39
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RE: Cannot get wings to stop rocking!!
ORIGINAL: Shogun
Something that nobody has mentioned yet, at least I don't recall reading it in the htread so excuse me if it has already been mentioned....
Seal the gaps on the control surfaces. I have found that for small models, by that I mean ANYTHING under 35%, this really can help a grat immensely. I don't care how tight your gaps are the airflow through the ailerons will differ on either side and hence they are not operating in a balanced state. This same rule applies the elevator halves as well, just do it if you haven't already, you might be surprised at the results.
The lateral balance is crucial and if you have a heavy wing it will start the rocking process every time you pull the nose up and slow down.
As NEAR to perfect symetrical elevator throws as can be acheived on dual elevator servo equipped planes is a must. Make 2 pointers from a pair of clothespins and carbon rods that are about 12 inches long and clip them on the elevators. Next cycle the elevators up and down and observe the pointers, do they track each other to within an 1/8th of an inch of each other throughout the arc from full up to full down throw? If they don't fix it so they do.
Is the model touchy in a hover in calm air? If so you probably have too much throw or too little expo. If your chasing the plane to keep the nose up and in one place you need to work on getting it stable in a hover where small, quick corrections are all that is needed to hold a steady position. My rule is if you are fighting the plane in a hover you will fight it in other maneuvers as well, like harriers, especially harriers.
Too much expo, this will get you every time. I have found that the less the better, but you still will NEED some to be able to smoothly control and correct small errors. The problem is, if you use too much you will always be behind the plane every time you attempt a correction. If you use to little your corrections will have to be almost perfectly timed and executed. So how much is too much expo? I've found that most planes are happy with between -20 and -30(Futaba or Hitec) on the rudder and about the same on the elevator, sometimes a bit more but never more than -35. It seems that once you start cranking in more than -35 the controls it's extremely difficult to maintain any feel for the plane as the controls become far too soft. Sure I know some guys that can fly this way and I know just as many that use no expo at all....most of us are not goine to be successful if we try flying in either of these categories IMO.
Servo blow back can also be an issue that many might neglect to check for. Make sure your controls are maximizing servo power and resolution. I can't recall the number of times that I helped a guy out at the field or on-line by telling them to move their clevises all the way out on their horns and in some on their servo arms and then fly the plane. Without fail they noticed a big improvement in control response immediately even though their control throws were sometimes cut nearly in half. It's my humble opinion that more guys get into trouble by worrying about having big throws than any other single issue, all of my planes use about 30 degrees on the rudder and elevators and will do whatever I want, ailerons are a matter of personal preference so set them up for a roll rate that doesn't give you a headache and fly it.
Something that nobody has mentioned yet, at least I don't recall reading it in the htread so excuse me if it has already been mentioned....
Seal the gaps on the control surfaces. I have found that for small models, by that I mean ANYTHING under 35%, this really can help a grat immensely. I don't care how tight your gaps are the airflow through the ailerons will differ on either side and hence they are not operating in a balanced state. This same rule applies the elevator halves as well, just do it if you haven't already, you might be surprised at the results.
The lateral balance is crucial and if you have a heavy wing it will start the rocking process every time you pull the nose up and slow down.
As NEAR to perfect symetrical elevator throws as can be acheived on dual elevator servo equipped planes is a must. Make 2 pointers from a pair of clothespins and carbon rods that are about 12 inches long and clip them on the elevators. Next cycle the elevators up and down and observe the pointers, do they track each other to within an 1/8th of an inch of each other throughout the arc from full up to full down throw? If they don't fix it so they do.
Is the model touchy in a hover in calm air? If so you probably have too much throw or too little expo. If your chasing the plane to keep the nose up and in one place you need to work on getting it stable in a hover where small, quick corrections are all that is needed to hold a steady position. My rule is if you are fighting the plane in a hover you will fight it in other maneuvers as well, like harriers, especially harriers.
Too much expo, this will get you every time. I have found that the less the better, but you still will NEED some to be able to smoothly control and correct small errors. The problem is, if you use too much you will always be behind the plane every time you attempt a correction. If you use to little your corrections will have to be almost perfectly timed and executed. So how much is too much expo? I've found that most planes are happy with between -20 and -30(Futaba or Hitec) on the rudder and about the same on the elevator, sometimes a bit more but never more than -35. It seems that once you start cranking in more than -35 the controls it's extremely difficult to maintain any feel for the plane as the controls become far too soft. Sure I know some guys that can fly this way and I know just as many that use no expo at all....most of us are not goine to be successful if we try flying in either of these categories IMO.
Servo blow back can also be an issue that many might neglect to check for. Make sure your controls are maximizing servo power and resolution. I can't recall the number of times that I helped a guy out at the field or on-line by telling them to move their clevises all the way out on their horns and in some on their servo arms and then fly the plane. Without fail they noticed a big improvement in control response immediately even though their control throws were sometimes cut nearly in half. It's my humble opinion that more guys get into trouble by worrying about having big throws than any other single issue, all of my planes use about 30 degrees on the rudder and elevators and will do whatever I want, ailerons are a matter of personal preference so set them up for a roll rate that doesn't give you a headache and fly it.
He speaks.....[X(]
Excellent post Scott. Every bit of that is excellent information IMO. I had not thought about the gaps but you are right on.
On the expo and how it effects response, for me, it depends on the amount of throw you have. For me, the less throw I have the less expo I need. I judge this by getting my low rate expo exactly where I want it first. Once I have the low rate expo and throw setup just right I go into the high rates and look at the curves on the transmitter screen. My 9C and 9Z both have a chart display that let you see the curves and you can actually see the curve move as you manipulate the expo on the transmitter. What I try to do I set the expo on high rate so that at the bottom of the curve (around the neutral point) on low rate and high rate match. Basically that means that while looking at this screen you flip the rate switch back on forth and the high/low rate curves are exactly the same within say 25% of center. Beyond 25% the low rate curve will actually not curve all that much (less expo = more linear) and the high rate will sharply curve upward and the expo loses effect as you increase throw and the control moves rapidly towards full deflection (more expo= less linear/bigger curve.)
However, on the rudder I do not use dual rates on a 3D plane. I am always setup for max throw which may be as much as 50 degrees or basically all I can get. Then I dial in about -60 expo, what that does is makes the rudder "feel" like it is on low rates whn I am trying to make feathering rudder corrections, but when I am hovering or doing a rolling harrier where I am using a lot of deflection anyway, at the point out on the curve where I am operating the expo has become uneffective and I have that linear feel. This only really works for me on the rudder though. I cannot make it feel right on the elevator or ailerons, ESPECIALLY the elevator. There I use dual rates.
I am not disagreeing with you in any way, I think your comments are right on. Just interjecting a little detail on how I have found to make good use of expo.[8D]
08-08-2006 | 09:50 AM
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RE: Cannot get wings to stop rocking!!
Good points, Mike. I find I do like dual rates on the rudder. Even while doing 3D, I like to fly up and do a nice, long slow roll (the pattern thing, remember?) to break things up. Its just easier for me to nail this kind of move using rates. Also, when doing rolling harriers I find I still over control the rudder if I don't have it on a lower rate. So I set up my third rates as like a specialty rate, with everything high except the rudder. This will probably change as I develop.
08-08-2006 | 09:56 AM
#41
RE: Cannot get wings to stop rocking!!
Hi guys,
I just got my turbine waiver, so I 've been kind of busy with my jet lately. In the mean time I've sent my DA-50 in for repair (bad ignition).
The gaps of all surfaces are sealed, and the elevator throw seems symetrical.
NOBODY here has paid attention to my question regarding prop size. You guys are getting way too deep into the little details thay are only good once the basics are estrablished. But thanks anyways. Once I set up my Harrier and get the wings to stop rocking I will pay attention to to Expo's, elevator diff throw, and all the fine tuning you guy's have mentioned. Im pretty sure that the wing rock is due to something very basic.
1. I will swittch to a larger diameter/lower pitch prop. I still think that the rcking is due to lack of prop wash underneath the wings and. anyway, that is just how it "feels".
2. I will do a lateral balance check. This model is an ARF so I don't expect one wing to be 1lb heavier than the other.
3. For the time being, ELE travel on hig rates will remain at 45 deg with 30% expo. Im comfortbale with it and the plane feels good.
4. Will re-check the CG. It may be too far aft.
5.WIll add a Sullivan Smoker, becasue it this piece of S$it will not harrier I can still fly some pretty neat figures using smoke.
I will let you guys know how the next fligght goes.
Thank you all for your input, Masters.
later,
Quique Somenzini
I just got my turbine waiver, so I 've been kind of busy with my jet lately. In the mean time I've sent my DA-50 in for repair (bad ignition).
The gaps of all surfaces are sealed, and the elevator throw seems symetrical.
NOBODY here has paid attention to my question regarding prop size. You guys are getting way too deep into the little details thay are only good once the basics are estrablished. But thanks anyways. Once I set up my Harrier and get the wings to stop rocking I will pay attention to to Expo's, elevator diff throw, and all the fine tuning you guy's have mentioned. Im pretty sure that the wing rock is due to something very basic.
1. I will swittch to a larger diameter/lower pitch prop. I still think that the rcking is due to lack of prop wash underneath the wings and. anyway, that is just how it "feels".
2. I will do a lateral balance check. This model is an ARF so I don't expect one wing to be 1lb heavier than the other.
3. For the time being, ELE travel on hig rates will remain at 45 deg with 30% expo. Im comfortbale with it and the plane feels good.
4. Will re-check the CG. It may be too far aft.
5.WIll add a Sullivan Smoker, becasue it this piece of S$it will not harrier I can still fly some pretty neat figures using smoke.
I will let you guys know how the next fligght goes.
Thank you all for your input, Masters.
later,
Quique Somenzini
08-08-2006 | 10:04 AM
#42
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RE: Cannot get wings to stop rocking!!
That was funny!
I read your Q about the prop, but don't have a DA 50, so any comment I made woud be even less reliable than my other ones. Good luck with the jet, QQ.....
I read your Q about the prop, but don't have a DA 50, so any comment I made woud be even less reliable than my other ones. Good luck with the jet, QQ.....
08-08-2006 | 10:26 AM
#43
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RE: Cannot get wings to stop rocking!!
I have a DA 50 and for 3D I like a 22 x 8 better than anything else. I've flown 23 x 8 Mej, 24 x 8 Menz and 23 x 8 NX and the engine simply will not rpm in the range where it makes best power for 3D. With these larger props the thrust is huge but the throttle response is lacking and the rpms are below where the DA really shines, over 7K is where the best performance is obtained with the DA 50 IMO. 3D flying is all about quick throttle response and big thrust changes, loose either one of those and your going to get low and regret it.
IME wing rocking is never about a single, simple thing it's always a combination of small things all working against you at the same time.
IME wing rocking is never about a single, simple thing it's always a combination of small things all working against you at the same time.
08-08-2006 | 10:48 AM
#44
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RE: Cannot get wings to stop rocking!!
ORIGINAL: Shogun
I have a DA 50 and for 3D I like a 22 x 8 better than anything else. I've flown 23 x 8 Mej, 24 x 8 Menz and 23 x 8 NX and the engine simply will not rpm in the range where it makes best power for 3D. With these larger props the thrust is huge but the throttle response is lacking and the rpms are below where the DA really shines, over 7K is where the best performance is obtained with the DA 50 IMO. 3D flying is all about quick throttle response and big thrust changes, loose either one of those and your going to get low and regret it.
IME wing rocking is never about a single, simple thing it's always a combination of small things all working against you at the same time.
I have a DA 50 and for 3D I like a 22 x 8 better than anything else. I've flown 23 x 8 Mej, 24 x 8 Menz and 23 x 8 NX and the engine simply will not rpm in the range where it makes best power for 3D. With these larger props the thrust is huge but the throttle response is lacking and the rpms are below where the DA really shines, over 7K is where the best performance is obtained with the DA 50 IMO. 3D flying is all about quick throttle response and big thrust changes, loose either one of those and your going to get low and regret it.
IME wing rocking is never about a single, simple thing it's always a combination of small things all working against you at the same time.
Falconwings, [8D] I am going to beat this horse dead I guess... A LOT of the problem is with what is going on with the sticks. That is the honest truth, based on my experience of going from a guy who used to struggle with wingrock to a guy who now struggles to find a plane that "does" wingrock. I understand that this planes rocks and others didnt seem as bad, I know that you feel that there may be something "wrong" with the plane, prop, whatever... and you may be right.
BUT,
I dont want to be argumentative, but you are asking why your plane wingrocks and we are trying to help you figure it out. It only takes about and ounce or 2 of imbalance (depending on the wingspan) for lateral balance related stability to be compromised, it does not take a pound. Especially when you are talking about stall (3D) characteristics. 3D planes need to be setup perfect in every way to really fly well and ARF are the worlds worse for being out of balance.
I do not believe that prop size is going to help/hurt your wingrock problem, unless the ailerons stop way short of the fuselage so that propwash is not getting to them where you have some aileron control in high alpha. Lift in high alpha is not an issue and the intent is to stall the wing and fly strictly on thrust, with only propwash to make the control surfaces functional.
Something else you may try is more elevator deflection. You want the wing to stall, flatout in a harrier or elevator. You get enough elevator throw and the CG right and you elevators will be hands off the rudder and ailerons and throttle. Once those wings stall there is no doubt and they will not rock. But even there, typically as soon as you start to ease in the throttle the wings want to rock as they establish lift, stall, establish lift, stall one wing and then the other.
Want to stop the wingrock?
Practice, check lateral balance, practice, tweek the CG, practice, play with deflection rates, practice, chck expo and make sure there is not too much or too little, practice, try a different prop, practice, practice practice practice. One day you are going to look up and realize that suddenly the wingrock mysteriously went away. You will go back to the other planes that you quit flying and realize that they mysteriously stopped wingrocking too!![8D]
08-08-2006 | 11:04 AM
#45
RE: Cannot get wings to stop rocking!!
Well, non of my other mnodels did this so bad.
If the problem is in my fingers, then I would admit it. I think there is something else going on. It usaully takes me no time to take any model and hover it and harrier it. But this Yak is beating me up!!
It shold never have to be this complicated. You are right, practice makes perfect. But it shouldn't be so hard to tame that beast.
I wish I could show you a video so you see what im talking about. Im talking about a model airplane literally dancing. For the record, it can still harrier with the wing rock, just looks butt ugly.
I do really appreciate your input Mike. And I do think that my fingers are quite fine.
David, I mean Quique.
If the problem is in my fingers, then I would admit it. I think there is something else going on. It usaully takes me no time to take any model and hover it and harrier it. But this Yak is beating me up!!
It shold never have to be this complicated. You are right, practice makes perfect. But it shouldn't be so hard to tame that beast.
I wish I could show you a video so you see what im talking about. Im talking about a model airplane literally dancing. For the record, it can still harrier with the wing rock, just looks butt ugly.
I do really appreciate your input Mike. And I do think that my fingers are quite fine.
David, I mean Quique.
08-08-2006 | 11:05 AM
#46
RE: Cannot get wings to stop rocking!!
ORIGINAL: Shogun
I have a DA 50 and for 3D I like a 22 x 8 better than anything else. I've flown 23 x 8 Mej, 24 x 8 Menz and 23 x 8 NX and the engine simply will not rpm in the range where it makes best power for 3D. With these larger props the thrust is huge but the throttle response is lacking and the rpms are below where the DA really shines, over 7K is where the best performance is obtained with the DA 50 IMO. 3D flying is all about quick throttle response and big thrust changes, loose either one of those and your going to get low and regret it.
IME wing rocking is never about a single, simple thing it's always a combination of small things all working against you at the same time.
I have a DA 50 and for 3D I like a 22 x 8 better than anything else. I've flown 23 x 8 Mej, 24 x 8 Menz and 23 x 8 NX and the engine simply will not rpm in the range where it makes best power for 3D. With these larger props the thrust is huge but the throttle response is lacking and the rpms are below where the DA really shines, over 7K is where the best performance is obtained with the DA 50 IMO. 3D flying is all about quick throttle response and big thrust changes, loose either one of those and your going to get low and regret it.
IME wing rocking is never about a single, simple thing it's always a combination of small things all working against you at the same time.
08-08-2006 | 11:21 AM
#47
My Feedback: (3)
RE: Cannot get wings to stop rocking!!
Then I would just start a priority list of "things to check" starting with those that you beleive are the most likely.
Start with those you think are most likely first and work your way down the list one at a time. Do not make 2 different changes at the same time (unless you think a combined change is the solution) so that you can tell what effect each thing has.
Here would be my suggested list in order, but you will have to decide on your own.
1. Look and see if there is any easy dead weight that you can find in the plane to lighten it up.
2. Test for lateral balance, it cannot hurt and making it perfect will only make the plane fly better.
3. Double check you CG and do a trim test to make sure that you are trimmed out for hands off vertical downlines, knife edge mixes are right and how the plane flies inverted hands off compared to upright hands off. Ideally you want it to require just a breath of down elevator in a vertical attitude, specifically an inverted 45 degree upline.
4. One you do that, try again. If it still rocks, change the prop to maybe a 23x8 see if propwash is an issue.
4. If it still wingrocks, increase your elevator throw 5 degrees at a time and see if there is a point where it stops or gets worse. 45-60 degrees is usually the ticket.
5. Then once you have exhausted effort, try increasing your high rate aileron throw or adjusting expo on the ailerons to see if you are reacting too slow/too fast.
After that, either practice till it stops OR pull all of the gear out of it and have a Bon Fire...
Then go order you a new plane!!
Start with those you think are most likely first and work your way down the list one at a time. Do not make 2 different changes at the same time (unless you think a combined change is the solution) so that you can tell what effect each thing has.
Here would be my suggested list in order, but you will have to decide on your own.
1. Look and see if there is any easy dead weight that you can find in the plane to lighten it up.
2. Test for lateral balance, it cannot hurt and making it perfect will only make the plane fly better.
3. Double check you CG and do a trim test to make sure that you are trimmed out for hands off vertical downlines, knife edge mixes are right and how the plane flies inverted hands off compared to upright hands off. Ideally you want it to require just a breath of down elevator in a vertical attitude, specifically an inverted 45 degree upline.
4. One you do that, try again. If it still rocks, change the prop to maybe a 23x8 see if propwash is an issue.
4. If it still wingrocks, increase your elevator throw 5 degrees at a time and see if there is a point where it stops or gets worse. 45-60 degrees is usually the ticket.
5. Then once you have exhausted effort, try increasing your high rate aileron throw or adjusting expo on the ailerons to see if you are reacting too slow/too fast.
After that, either practice till it stops OR pull all of the gear out of it and have a Bon Fire...
Then go order you a new plane!!
08-08-2006 | 11:40 AM
#48
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From: Omaha, NE
RE: Cannot get wings to stop rocking!!
Now that I think about it I also can't recall if anyone has mentione wing and tail incidence in the thread up till now. I simply can't stress this strongly enough, if you are trusting the ARF manufacturers to sell you straight, warp free planes out of the box then you are going to be buying stock in an asprine company.
NONE of the ARF's I have assembled have had their incidence correct, all had to be tweaked a bit to get them where they needed to be. warps are alos a concern and the use of an incidence meter can reveal their presence. If you have a warped panel or a mis-aligned stab(s) NO AMOUNT of tweaking/prop changing/practice will cure the problem.
As for the lateral balance it is crucial to get it as dead on as possible. I have experimented by adding as little as a 1/2 ounce to a wingtip and it turned a docile, easy to 3D plane into a handful that was much more difficult to hover and harrier smoothly.
Another mistake I see pretty often anymore is the assumption that this is easy and just because all of the other planes a guy has flown presented little to zero problems that they will all be that way. Sure there are some designs that are pure garbage but most simply need to be tweaked and massaged a bit to make them shine. If you got good results on the first try you were either lucky or you are easily satisfied with a plane that could potentially fly much better but we'll nver know because it's fine as it is...I know a LOL of guys that are that way, I'm not one of them.
NONE of the ARF's I have assembled have had their incidence correct, all had to be tweaked a bit to get them where they needed to be. warps are alos a concern and the use of an incidence meter can reveal their presence. If you have a warped panel or a mis-aligned stab(s) NO AMOUNT of tweaking/prop changing/practice will cure the problem.
As for the lateral balance it is crucial to get it as dead on as possible. I have experimented by adding as little as a 1/2 ounce to a wingtip and it turned a docile, easy to 3D plane into a handful that was much more difficult to hover and harrier smoothly.
Another mistake I see pretty often anymore is the assumption that this is easy and just because all of the other planes a guy has flown presented little to zero problems that they will all be that way. Sure there are some designs that are pure garbage but most simply need to be tweaked and massaged a bit to make them shine. If you got good results on the first try you were either lucky or you are easily satisfied with a plane that could potentially fly much better but we'll nver know because it's fine as it is...I know a LOL of guys that are that way, I'm not one of them.
08-08-2006 | 12:42 PM
#49
RE: Cannot get wings to stop rocking!!
ha,ha,ha your right Scott!
I also posted this question on the Giant Scale section, as the factroy pilot posts a lot over there.
He mentioned somehting that made lot of sense and could be my proboem, too low of a Harrier angle. I'm typically 45 degress or less when I move into position (wings rokcing of course) and then I just let it sit there at a shallow angle. I was asked to try it at 60 degrees or higher because supposedly that's where my model likes to hang out.
Why not, I'll give it a try as well.
Anyone seen a missing link yet?
I also posted this question on the Giant Scale section, as the factroy pilot posts a lot over there.
He mentioned somehting that made lot of sense and could be my proboem, too low of a Harrier angle. I'm typically 45 degress or less when I move into position (wings rokcing of course) and then I just let it sit there at a shallow angle. I was asked to try it at 60 degrees or higher because supposedly that's where my model likes to hang out.
Why not, I'll give it a try as well.
Anyone seen a missing link yet?
08-08-2006 | 02:15 PM
#50
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From: Lewiston, ID
RE: Cannot get wings to stop rocking!!
David,
I see something.
If your YAK will continue to harrier, even though its rocking like crazy, its controllable. Really. I had the CAP you mentioned earlier, the H9? At that time I couldn't truly do any 3D, but I could harrier that thing all over the sky. Just pull back and watch. No wing rock to speak of. Something to notice: a CAP 232 has a high forward stab. I scratch build lots of 3D planes I design myself. I commonly use a high forward stab because they're so good in harrier. I just finished a new one the other day with the stab much lower in the fuse. This plane is a bit looser in harrier, meaning it will rock if you let it. No problem, just stay on the ailerons and its fine. So while it still harriers great ( I was doing harriers inches off the ground on the maiden flight) its just different. I'm with Mike on this one.
I see something.
If your YAK will continue to harrier, even though its rocking like crazy, its controllable. Really. I had the CAP you mentioned earlier, the H9? At that time I couldn't truly do any 3D, but I could harrier that thing all over the sky. Just pull back and watch. No wing rock to speak of. Something to notice: a CAP 232 has a high forward stab. I scratch build lots of 3D planes I design myself. I commonly use a high forward stab because they're so good in harrier. I just finished a new one the other day with the stab much lower in the fuse. This plane is a bit looser in harrier, meaning it will rock if you let it. No problem, just stay on the ailerons and its fine. So while it still harriers great ( I was doing harriers inches off the ground on the maiden flight) its just different. I'm with Mike on this one.
