chipmuck
08-01-2012, 06:54 PM
#51
RE: chipmuck
Speed when you start scaling weight, reynolds numbers, compressability, etc... you will find that while your Extra has better performance, it is not that much different, and all of the same rules apply. Models can just eliminate some of the compromises required when there is a pilot onboard, and strength to weight ratios go up as size decreases, but the laws of aerodynamics don't change.
08-01-2012, 08:53 PM
#52
RE: chipmuck
ORIGINAL: jkpape
I'm sorry that you don't get it. P-factor does not exist in straight & level flight. It only exists during maneuvers involving high angles of attack, like climbing. For those of you who don't know what angle of attack is/means, here's the def: Angle of Attack is most frequently defined as the angle between the cord line of the wing, and the relative wind. Generally, it is sufficient to say that the angle of attack is simply the angular difference between where the wing is headed and where it is going. (per FAA's Flight training Handbook). The FAA's Flight training handbook is really good and is written such that an 8th grader can understand it. It can be downloaded from their web site free.
If torque reaction from the engine & propeller, corkscrewing effect of the slipstream, gyroscopic action of the propeller, and asymmetric loading of the propeller (P-factor) was not an issue with our models, there would be no need to do any trimming to them if they were built straight & true. Like it or not, all the trimming that you say you do to your aircraft is to counter the effect of those 4 items.
FYI: I've been building & flying model airplanes for 45 years of my 50 years on this earth. Also, I've been flying full scale for almost 25 years. I'm also an aircraft mechanic. My real job is a mechanical engineer.
I'm sorry that you don't get it. P-factor does not exist in straight & level flight. It only exists during maneuvers involving high angles of attack, like climbing. For those of you who don't know what angle of attack is/means, here's the def: Angle of Attack is most frequently defined as the angle between the cord line of the wing, and the relative wind. Generally, it is sufficient to say that the angle of attack is simply the angular difference between where the wing is headed and where it is going. (per FAA's Flight training Handbook). The FAA's Flight training handbook is really good and is written such that an 8th grader can understand it. It can be downloaded from their web site free.
If torque reaction from the engine & propeller, corkscrewing effect of the slipstream, gyroscopic action of the propeller, and asymmetric loading of the propeller (P-factor) was not an issue with our models, there would be no need to do any trimming to them if they were built straight & true. Like it or not, all the trimming that you say you do to your aircraft is to counter the effect of those 4 items.
FYI: I've been building & flying model airplanes for 45 years of my 50 years on this earth. Also, I've been flying full scale for almost 25 years. I'm also an aircraft mechanic. My real job is a mechanical engineer.
1. Set CG
2. Set pitch trim in combination with CG so airplane has no pitch change from 1/4 to full throttle
3. Aileron differential to eliminate adverse yaw and make rolls axial.
4. Check for rudder to pitch coupling. If need be, go back to step 1 and adjust CG to eliminate or reduce coupling and start over with step 2.
5. Check uplines, if the model veers right or left the first 100-150 feet of a full throttle climb then adjust side thrust. If model pulls or tucks, adjust up/down thrust.
6. Set throws and expo to suit sequence.
7. Adjust throttle curve ( personal preference )
8. Practice, practice, practice..........This will show weak spots in the trimming and lead to fine tuning all the above. Usually one small change is made at a time and flown a minimum of 10 flights to determine if it was a positive change or a negitive one.
I understand that some of you have as many years in this hobby as I but to what level? No dis-respect intended here but have either one of you ever averaged 15-20 flights a week of sequence flying trying to perfect (impossable task ) your flying?
08-01-2012, 09:44 PM
#53
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RE: chipmuck
I understand that some of you have as many years in this hobby as I but to what level? No dis-respect intended here but have either one of you ever averaged 15-20 flights a week of sequence flying trying to perfect ( impossable task ) your flying?
Are you one of them thar Pattern or IMAC Pilots?
Hum thought so, I know a few of them and it does show.
08-02-2012, 03:36 AM
#54
RE: chipmuck
One of the major issues at stake here is how to pronounce "Chipmuck" and did deHavilland have anything to do with this version of their trainer? Could Art Scholl and his dog, Aileron have flown in a "Super [Chipmuck]"?
08-02-2012, 05:37 AM
#55
RE: chipmuck
The definition of torque: "Something that produces or tends to produce torsion or rotation; the moment of a force or system of forces tending to cause rotation."
They are all "torque effects" and they all effect our aircraft to a certain degree. As said before every plane battles each to varying degrees. Without using sophisticated computer modeling or old school wind tunnel testing we will not have any hard data for you. We have to do it the old fashioned way. Try different fixes and test each one in turn, and since each plane is different we can only offer up what can be causing it and possible fixes, but I will tell you that I have 30+ years of model airplane experience and 19+ years, most of which was is as an instructor, of full scale experience, and when I fly a model just like a full scale, low and behold, it responds just like a full scale., For any of us to say, without actually being there, that one specific effect is the culprit and therefore one specific fix is the remedy is just not realistic. He has heard the various effects and each of their roles in the equation and now he needs to decide which fixes he will look into making and if they work for him or not.
Speed you have contradicted yourself and proven my point. You have said yourself it takes you upwards of 50 hrs of adjustments and testing to get it right for each airplane, and yet you can say, without knowing how his plane is set-up and how he actually fly's it, that right thrust is the fix. It is one of many things that alone or combined may be the issue. I would agree it is one of the most common issues, but without seeing the plane and flying it myself I know I can't say with any real certainty what will or wont fix it. Landing gear, thrust line, vertical stabilizer canted to one side, trims set way off, tail wheel alignment, etc... any one, or any combination, of these can be the culprit and they should all be checked in turn. He may find that many adjustments need to be made and will have a far better flying plane by the end.
They are all "torque effects" and they all effect our aircraft to a certain degree. As said before every plane battles each to varying degrees. Without using sophisticated computer modeling or old school wind tunnel testing we will not have any hard data for you. We have to do it the old fashioned way. Try different fixes and test each one in turn, and since each plane is different we can only offer up what can be causing it and possible fixes, but I will tell you that I have 30+ years of model airplane experience and 19+ years, most of which was is as an instructor, of full scale experience, and when I fly a model just like a full scale, low and behold, it responds just like a full scale., For any of us to say, without actually being there, that one specific effect is the culprit and therefore one specific fix is the remedy is just not realistic. He has heard the various effects and each of their roles in the equation and now he needs to decide which fixes he will look into making and if they work for him or not.
Speed you have contradicted yourself and proven my point. You have said yourself it takes you upwards of 50 hrs of adjustments and testing to get it right for each airplane, and yet you can say, without knowing how his plane is set-up and how he actually fly's it, that right thrust is the fix. It is one of many things that alone or combined may be the issue. I would agree it is one of the most common issues, but without seeing the plane and flying it myself I know I can't say with any real certainty what will or wont fix it. Landing gear, thrust line, vertical stabilizer canted to one side, trims set way off, tail wheel alignment, etc... any one, or any combination, of these can be the culprit and they should all be checked in turn. He may find that many adjustments need to be made and will have a far better flying plane by the end.
08-02-2012, 06:24 AM
#56
My Feedback: (6)
RE: chipmuck
ORIGINAL: cfircav8r
The definition of torque: ''Something that produces or tends to produce torsion or rotation; the moment of a force or system of forces tending to cause rotation.''
They are all ''torque effects'' and they all effect our aircraft to a certain degree. As said before every plane battles each to varying degrees. Without using sophisticated computer modeling or old school wind tunnel testing we will not have any hard data for you. We have to do it the old fashioned way. Try different fixes and test each one in turn, and since each plane is different we can only offer up what can be causing it and possible fixes, but I will tell you that I have 30+ years of model airplane experience and 19+ years, most of which was is as an instructor, of full scale experience, and when I fly a model just like a full scale, low and behold, it responds just like a full scale., For any of us to say, without actually being there, that one specific effect is the culprit and therefore one specific fix is the remedy is just not realistic. He has heard the various effects and each of their roles in the equation and now he needs to decide which fixes he will look into making and if they work for him or not.
Speed you have contradicted yourself and proven my point. You have said yourself it takes you upwards of 50 hrs of adjustments and testing to get it right for each airplane, and yet you can say, without knowing how his plane is set-up and how he actually fly's it, that right thrust is the fix. It is one of many things that alone or combined may be the issue. I would agree it is one of the most common issues, but without seeing the plane and flying it myself I know I can't say with any real certainty what will or wont fix it. Landing gear, thrust line, vertical stabilizer canted to one side, trims set way off, tail wheel alignment, etc... any one, or any combination, of these can be the culprit and they should all be checked in turn. He may find that many adjustments need to be made and will have a far better flying plane by the end.
The definition of torque: ''Something that produces or tends to produce torsion or rotation; the moment of a force or system of forces tending to cause rotation.''
They are all ''torque effects'' and they all effect our aircraft to a certain degree. As said before every plane battles each to varying degrees. Without using sophisticated computer modeling or old school wind tunnel testing we will not have any hard data for you. We have to do it the old fashioned way. Try different fixes and test each one in turn, and since each plane is different we can only offer up what can be causing it and possible fixes, but I will tell you that I have 30+ years of model airplane experience and 19+ years, most of which was is as an instructor, of full scale experience, and when I fly a model just like a full scale, low and behold, it responds just like a full scale., For any of us to say, without actually being there, that one specific effect is the culprit and therefore one specific fix is the remedy is just not realistic. He has heard the various effects and each of their roles in the equation and now he needs to decide which fixes he will look into making and if they work for him or not.
Speed you have contradicted yourself and proven my point. You have said yourself it takes you upwards of 50 hrs of adjustments and testing to get it right for each airplane, and yet you can say, without knowing how his plane is set-up and how he actually fly's it, that right thrust is the fix. It is one of many things that alone or combined may be the issue. I would agree it is one of the most common issues, but without seeing the plane and flying it myself I know I can't say with any real certainty what will or wont fix it. Landing gear, thrust line, vertical stabilizer canted to one side, trims set way off, tail wheel alignment, etc... any one, or any combination, of these can be the culprit and they should all be checked in turn. He may find that many adjustments need to be made and will have a far better flying plane by the end.
08-02-2012, 08:25 AM
#57
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RE: chipmuck
To bad there isn't any current model airplane engines made that turn counter clockwise. If the op could swap out his current engine to one that turned counterclockwise, he would find that his airplane would now try to turn left.
08-02-2012, 08:43 AM
#58
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RE: chipmuck
To bad there isn't any current model airplane engines made that turn counter clockwise. If the op could swap out his current engine to one that turned counterclockwise, he would find that his airplane would now try to turn left.
Then we could add 3 more pages to this thread.
08-02-2012, 03:49 PM
#59
RE: chipmuck
ORIGINAL: cfircav8r
The definition of torque: "Something that produces or tends to produce torsion or rotation; the moment of a force or system of forces tending to cause rotation."
They are all "torque effects" and they all effect our aircraft to a certain degree. As said before every plane battles each to varying degrees. Without using sophisticated computer modeling or old school wind tunnel testing we will not have any hard data for you. We have to do it the old fashioned way. Try different fixes and test each one in turn, and since each plane is different we can only offer up what can be causing it and possible fixes, but I will tell you that I have 30+ years of model airplane experience and 19+ years, most of which was is as an instructor, of full scale experience, and when I fly a model just like a full scale, low and behold, it responds just like a full scale., For any of us to say, without actually being there, that one specific effect is the culprit and therefore one specific fix is the remedy is just not realistic. He has heard the various effects and each of their roles in the equation and now he needs to decide which fixes he will look into making and if they work for him or not.
Speed you have contradicted yourself and proven my point. You have said yourself it takes you upwards of 50 hrs of adjustments and testing to get it right for each airplane, and yet you can say, without knowing how his plane is set-up and how he actually fly's it, that right thrust is the fix. It is one of many things that alone or combined may be the issue. I would agree it is one of the most common issues, but without seeing the plane and flying it myself I know I can't say with any real certainty what will or wont fix it. Landing gear, thrust line, vertical stabilizer canted to one side, trims set way off, tail wheel alignment, etc... any one, or any combination, of these can be the culprit and they should all be checked in turn. He may find that many adjustments need to be made and will have a far better flying plane by the end.
The definition of torque: "Something that produces or tends to produce torsion or rotation; the moment of a force or system of forces tending to cause rotation."
They are all "torque effects" and they all effect our aircraft to a certain degree. As said before every plane battles each to varying degrees. Without using sophisticated computer modeling or old school wind tunnel testing we will not have any hard data for you. We have to do it the old fashioned way. Try different fixes and test each one in turn, and since each plane is different we can only offer up what can be causing it and possible fixes, but I will tell you that I have 30+ years of model airplane experience and 19+ years, most of which was is as an instructor, of full scale experience, and when I fly a model just like a full scale, low and behold, it responds just like a full scale., For any of us to say, without actually being there, that one specific effect is the culprit and therefore one specific fix is the remedy is just not realistic. He has heard the various effects and each of their roles in the equation and now he needs to decide which fixes he will look into making and if they work for him or not.
Speed you have contradicted yourself and proven my point. You have said yourself it takes you upwards of 50 hrs of adjustments and testing to get it right for each airplane, and yet you can say, without knowing how his plane is set-up and how he actually fly's it, that right thrust is the fix. It is one of many things that alone or combined may be the issue. I would agree it is one of the most common issues, but without seeing the plane and flying it myself I know I can't say with any real certainty what will or wont fix it. Landing gear, thrust line, vertical stabilizer canted to one side, trims set way off, tail wheel alignment, etc... any one, or any combination, of these can be the culprit and they should all be checked in turn. He may find that many adjustments need to be made and will have a far better flying plane by the end.
Mike, yes I do fly pattern and IMAC. You said that like it is a bad thing LOL. As of late I have gone back to my roots and have been pylon racing again. I'm having a blast doing so. I don't know how far back you go but as a teen my racing mentors were Jim Kelly, Paul Benezra, Jeff Carpenter, Lou Rodriquez and Rusty Van Baron. I have found that lots of these trimming methods apply to my race planes as well.
08-02-2012, 05:49 PM
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RE: chipmuck
Mike, yes I do fly pattern and IMAC. You said that like it is a bad thing LOL.
Guess I'm just too humble.
Not much of a problem for most of the Pattern/IMAC guys that I know.
