AILERON TRIMMING.
10-21-2009, 04:48 AM
#1
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AILERON TRIMMING.
I am trying to find out a technical answer to a trimming problem with computer transmitters.
The figures described are for a theory and not practical purpose.
I bring out my latest unflown model that I have set up on computer radio using dual wing servos for the ailerons with the menu set in FLAPERON mode.
I have set the ailerons up as level as possible and assume that everything is straight.
The right and left aileron trims, in the menu SUB TRIM are at zero %.
I fly the model and have to bring in a little RIGHT aileron trim to have the model fly dead straight using the digital trims on the Tx.
I land the model and note the aileron indicator trim shows ie. +8
Any deviations in the ailerons from level are so small as not to be measured.
As it is good and necessary practice with Tx. with multiple model capabilities, I want the Tx. set at zero for my other models.
I go into the SUB TRIM menu prior to bringing the aileron trim "lever" back to neutral.
In the sub menu I now have borh right and left aileron trims to be altered.
WHAT ALTERATIONS TO THE SUB TRIMS DO I MAKE?
+4 or -4 on each or +8 or -8 on one or the other. Most likely trial and error would sort it out, but this is a computer Tx. and there must be a definite answer.
Can anyone advise me.
The figures described are for a theory and not practical purpose.
I bring out my latest unflown model that I have set up on computer radio using dual wing servos for the ailerons with the menu set in FLAPERON mode.
I have set the ailerons up as level as possible and assume that everything is straight.
The right and left aileron trims, in the menu SUB TRIM are at zero %.
I fly the model and have to bring in a little RIGHT aileron trim to have the model fly dead straight using the digital trims on the Tx.
I land the model and note the aileron indicator trim shows ie. +8
Any deviations in the ailerons from level are so small as not to be measured.
As it is good and necessary practice with Tx. with multiple model capabilities, I want the Tx. set at zero for my other models.
I go into the SUB TRIM menu prior to bringing the aileron trim "lever" back to neutral.
In the sub menu I now have borh right and left aileron trims to be altered.
WHAT ALTERATIONS TO THE SUB TRIMS DO I MAKE?
+4 or -4 on each or +8 or -8 on one or the other. Most likely trial and error would sort it out, but this is a computer Tx. and there must be a definite answer.
Can anyone advise me.
10-21-2009, 10:33 AM
#4
Senior Member
RE: AILERON TRIMMING.
ORIGINAL: misterv
WHAT ALTERATIONS TO THE SUB TRIMS DO I MAKE?
+4 or -4 on each or +8 or -8 on one or the other. Most likely trial and error would sort it out, but this is a computer Tx. and there must be a definite answer.
Can anyone advise me.
WHAT ALTERATIONS TO THE SUB TRIMS DO I MAKE?
+4 or -4 on each or +8 or -8 on one or the other. Most likely trial and error would sort it out, but this is a computer Tx. and there must be a definite answer.
Can anyone advise me.
You'll get a better response to this question about setting your radio from the Radio Forum, so I'm moving the thread there.
10-21-2009, 11:39 AM
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RE: AILERON TRIMMING.
ORIGINAL: Jezmo
My Futaba saves trim settings per model memory as does my Spektrum.
My Futaba saves trim settings per model memory as does my Spektrum.
10-21-2009, 12:00 PM
#6
RE: AILERON TRIMMING.
Can you find a way to reset that reading to zero?
The physical deflection or trim will remain, as well as any difference of angles with the other aileron.
Just trying to re-trim to zero, will take the trim to the original un-trimmed condition.
For a mechanical radio, you would need to adjust it manually with the clevis, in order to get the trim stab and the servo centered to zero.
The physical deflection or trim will remain, as well as any difference of angles with the other aileron.
Just trying to re-trim to zero, will take the trim to the original un-trimmed condition.
For a mechanical radio, you would need to adjust it manually with the clevis, in order to get the trim stab and the servo centered to zero.
10-21-2009, 12:25 PM
#7
RE: AILERON TRIMMING.
ORIGINAL: misterv
I am trying to find out a technical answer to a trimming problem with computer transmitters.
The figures described are for a theory and not practical purpose.
(snip)
I am trying to find out a technical answer to a trimming problem with computer transmitters.
The figures described are for a theory and not practical purpose.
(snip)
What make & model of transmitter are you talking about? and...
What does the manual say?
You have described a computer transmitter with analog slide trim tabs. Some HiTec transmitters and the Polk transmitter use them, and they both provide manuals that describe clearly how to bring the trim tab back to the middle position while retaining the trim memory.
That feature is in Trim Memory, if I recall correctly, but look it up in your manual.
Again, it would help to know what make & model transmitter you're talking about. And, again, the process is undoubtedly described in the manual.
Good luck,
Dave Olson
10-21-2009, 12:37 PM
#8
My Feedback: (5)
RE: AILERON TRIMMING.
On the JR9303 both the trims and subtrims are stored for each model. My guess this is true for all JR and Spektrum computer transmitters. The purpose of the subtrim is to center the servo arm when the stick is at neutral if that is what you want. If the servo arm is off-center, it will give you aileron differential. For my sailplane ailerons, the subtrims are set high to get more differential needed for crow landing. For my pattern they are initially set to whatever is needed to square up the servo arm. If the plane needs differential, I dial it in with the appropriate menu.
Allan
10-21-2009, 12:52 PM
#9
Senior Member
My Feedback: (55)
RE: AILERON TRIMMING.
If I understand your concern it is that you do not want the trim you made to the model you just flew to carry over to the next model and you want to know how to set the trims to zero with the sub trim to prevent that from happening. Let me suggest that you do not fully understand how the computer radios work in this area because when you turn your radio to a different model then all of the trims for the model you are leaving will be kept in memory for that model and only that model. The new model you have selected starts out at zero or base configuration regardless of what you did to the last model. Most radios allow you to copy one model into another model memory slot but that would have to be done intentionally. So to answer your question about how to keep the new model trims at zero the answer is that you do not have to do anything. When you go back to the first model the trims will be just like you left them after the flight while the new model will start with all trims at zero.
Howard
Howard
10-21-2009, 01:35 PM
#10
My Feedback: (2)
RE: AILERON TRIMMING.
The way I read your question, you are trimming your model using the Trim Levers on your Tx, which is the correct way to do it. Your next step would be to mechanically Trim the aircraft by Shortening or Lengthening the Pushrod and then setting the Trim Lever on the Tx back to Zero.
When I first set up a new aircraft, I Reset the Model Memory back to Factory Defaults. All Trims, SubTrims, ATV/EPA, DR/Expo are set to Zero. Turn on the Tx and Rx. The Servos will go to Neutral. Attach the Servo Arm so that it is as close to 90 deg to the Servo Body as possible. If the Servo Arm is still not quite at 90 deg to the Servo Body, use SubTrim to bring the Servo Arm to 90 Deg. That is the only time I use SubTrim. Excessive amounts of SubTrim reduce the amount of Servo Travel you have.
With older computer radios like the Futaba T6XAS, which did not have Digital Trims, you would Set the Trim Lever, to Trim the model, set the Tx to Memorize the Trim Setting, and then Set the Trim Lever back to Zero. I assume you have a Computer Radio with Digital Trims.
When I first set up a new aircraft, I Reset the Model Memory back to Factory Defaults. All Trims, SubTrims, ATV/EPA, DR/Expo are set to Zero. Turn on the Tx and Rx. The Servos will go to Neutral. Attach the Servo Arm so that it is as close to 90 deg to the Servo Body as possible. If the Servo Arm is still not quite at 90 deg to the Servo Body, use SubTrim to bring the Servo Arm to 90 Deg. That is the only time I use SubTrim. Excessive amounts of SubTrim reduce the amount of Servo Travel you have.
With older computer radios like the Futaba T6XAS, which did not have Digital Trims, you would Set the Trim Lever, to Trim the model, set the Tx to Memorize the Trim Setting, and then Set the Trim Lever back to Zero. I assume you have a Computer Radio with Digital Trims.
10-23-2009, 08:40 AM
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RE: AILERON TRIMMING.
I'm sorry,you are all missing the point and maybe I have not made myself clear as to what I am asking.
The prolem only refers whilst using FLAPERON mode and most JR tx. give you the ability to trim both aileron servos individually. Some sets even in flaperon mode still only trim both aileron servos together.
Firstly I am using JR 9 transmitters and I know my transmitters very well. I have been using JR 10 on helis for many years both as a hobby and a profession, so there is no problem there. Just try some mixing on scale helis with a 10 and it sorts you out.
I know that the set retains all the trims for individual models but if you fly another model than the current one and do not bring you digital trims on the face of the Tx. back to neutral after you have centered, that trim will effect the next model.
So therefore it is good practice, and necessary to have your trims on the front of the set at neutral prior to your first flight with the next model.
If you were to fly your 'second' model with any trims off neutral on the front of the Tx. your model would be effected even though the set retains the SUB TRIM settings you originally set for that model.
There is no problem at all when you are in NORMAL wing mode but whilst in FLAPERON mode you have a trim on your TX moving both ailerons to get straight flight. Then on landing you go into the menu SUB TRIM and dial in the deflection figure shown on your Tx. But now you have TWO aileron trims to change in order to neutralise the trim set up on the Tx. prior to bringing the TX. aileron trim back to neutral.
Do you change both aileron trims 50% of the reading, or a left aileron 100% of the reading, or a right aileron trim 100% of the trim deflection as shown?.
The prolem only refers whilst using FLAPERON mode and most JR tx. give you the ability to trim both aileron servos individually. Some sets even in flaperon mode still only trim both aileron servos together.
Firstly I am using JR 9 transmitters and I know my transmitters very well. I have been using JR 10 on helis for many years both as a hobby and a profession, so there is no problem there. Just try some mixing on scale helis with a 10 and it sorts you out.
I know that the set retains all the trims for individual models but if you fly another model than the current one and do not bring you digital trims on the face of the Tx. back to neutral after you have centered, that trim will effect the next model.
So therefore it is good practice, and necessary to have your trims on the front of the set at neutral prior to your first flight with the next model.
If you were to fly your 'second' model with any trims off neutral on the front of the Tx. your model would be effected even though the set retains the SUB TRIM settings you originally set for that model.
There is no problem at all when you are in NORMAL wing mode but whilst in FLAPERON mode you have a trim on your TX moving both ailerons to get straight flight. Then on landing you go into the menu SUB TRIM and dial in the deflection figure shown on your Tx. But now you have TWO aileron trims to change in order to neutralise the trim set up on the Tx. prior to bringing the TX. aileron trim back to neutral.
Do you change both aileron trims 50% of the reading, or a left aileron 100% of the reading, or a right aileron trim 100% of the trim deflection as shown?.
10-23-2009, 11:53 AM
#12
RE: AILERON TRIMMING.
http://www.rcuniverse.com/forum/forumid_116/tt.htm
That's the JR Support forum in the Radio Manufacturer Direct Support forums.
Good Luck,
Dave Olson
That's the JR Support forum in the Radio Manufacturer Direct Support forums.
Good Luck,
Dave Olson
10-23-2009, 01:05 PM
#13
My Feedback: (5)
RE: AILERON TRIMMING.
mysterv,
You are probably using a JR9 rather than a 9303. I would be surprised that your transmitter doesn’t store the trims for each model independentlyas your transmitter has digital trims. If all your trims were analog, I could understand your problem. Would you go to an unused model slot and reset it? Take a look at the TRIM menu, it is a submenu of the MONITOR menu. For a reset model, all the trims should be zeros. All my pattern planes use flaperons. They all have different trims stored.
As a test, in this unused model memory, set your trims to some extreme values. Switch to another model. Take a look at its trims. I would bet they are different and if you wentback to the test model, yourextreme trim settings would still be there. What you describe was somewhat similar to the procedure used when the trims were analog.
Allan
10-23-2009, 01:50 PM
#14
My Feedback: (2)
RE: AILERON TRIMMING.
It sounds like you have Analog Trims and not Digital Trims, on the face of your Tx.
With Analog Trims, you have to Trim the aircraft, Set the Trim Memory, and Move the Trim Levers back to Neutral, for each Model Memory. If you Move the Trim Levers off Neutral, and change Model Memories, you need to remember to Move the Trim Levers back to Neutral or it will affect the Trim on the next Model Memory you choose.
Digital Trims cannot be changed when the Tx is turned off. They stay in the Model Memory until you turn on the Tx and change them. When you Change a Digital Trim, for a particular Model Memory, it does not affect another Model Memroy's Trim Settings.
SubTrim is just used for minor adjustments to move the Servo Arm to 90 deg when you first set up a servo. It is not used from major Trim Adjustments.
The Trim Levers, on the face of the Tx, are for Aileron, Elevator, Rudder, and Throttle. If you use the Flapperon Program, you connect the Right Aileron servo to the Aileron Channel and the Left Aileron servo to the Flap Channel. The Flapperon Program mixes the Aileron and Flap channel. The Aileron Trim Lever affects both channels equally. If you need to separately Trim the Right or Left Aileron, you can do that in the EPA/Travel Adjustment or in the Flapperon Program Settings, after you have made Mechanical Adjustments to the Aileron Pushrods.
When using the Flapperon program, if you are not using Ailerons as Flaps, you need to Turn OFF the Flap Trim Setting or Set it to Zero, otherwise, the Flap Knob will change the Aileron Trim. I have seen a number of New RC Pilots who forget to Turn OFF Flap Trim before they set up the Flapperon Settings. If they accidentally hit the Flap Knob or Flap Switch, while flying, it will throw the Ailerons out of Trim.
With Analog Trims, you have to Trim the aircraft, Set the Trim Memory, and Move the Trim Levers back to Neutral, for each Model Memory. If you Move the Trim Levers off Neutral, and change Model Memories, you need to remember to Move the Trim Levers back to Neutral or it will affect the Trim on the next Model Memory you choose.
Digital Trims cannot be changed when the Tx is turned off. They stay in the Model Memory until you turn on the Tx and change them. When you Change a Digital Trim, for a particular Model Memory, it does not affect another Model Memroy's Trim Settings.
SubTrim is just used for minor adjustments to move the Servo Arm to 90 deg when you first set up a servo. It is not used from major Trim Adjustments.
The Trim Levers, on the face of the Tx, are for Aileron, Elevator, Rudder, and Throttle. If you use the Flapperon Program, you connect the Right Aileron servo to the Aileron Channel and the Left Aileron servo to the Flap Channel. The Flapperon Program mixes the Aileron and Flap channel. The Aileron Trim Lever affects both channels equally. If you need to separately Trim the Right or Left Aileron, you can do that in the EPA/Travel Adjustment or in the Flapperon Program Settings, after you have made Mechanical Adjustments to the Aileron Pushrods.
When using the Flapperon program, if you are not using Ailerons as Flaps, you need to Turn OFF the Flap Trim Setting or Set it to Zero, otherwise, the Flap Knob will change the Aileron Trim. I have seen a number of New RC Pilots who forget to Turn OFF Flap Trim before they set up the Flapperon Settings. If they accidentally hit the Flap Knob or Flap Switch, while flying, it will throw the Ailerons out of Trim.
10-26-2009, 08:11 AM
#16
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RE: AILERON TRIMMING.
OK. let's try again and let's also assume I know how to operate a computer radio Tx. although from the replies most seem not to beleive that.
ie. I have a very badly built model that is crooked and uses ONE aileron servo with Tx.set in NORMAL WING mode.
On flying it veers badly to the left,very bad... I start pulsing in DIGITAL right aileron trim in an endevour to correct this. I run the trim all the way to 100% right aileron trim but the model still veers to the left.
I land the model.
Being an idiot I do not know how to adjust a quick link and anyhow I have spent many hundreds of dollars on this "you beaut" computer set that does EVERYTHING.
I go into the menu.... SUB TRIM... I can now dial in 100% right trim and then neutralise the digital trim on the front of the Tx. and I am back to having a model that still veers SLIGHTly to the left. However I now have 100% travel on the aileron DIGITAL trim to straighten the model on the next flight which I do and all is OK.(please.. dont tell me I shouldn't do it this way)
NOW:
Some bright spark suggests I use TWO servos on the aileron and set the Tx. up to FLAPERON WING mode.
I fly the model and it screams over to the left as before and I bring the AILERON DIGITAL trim on the tx, over to the right to try and adjust it.
I still need more trim so I land and go into the menu again and "WOW" , I now have both a RIGHT AILERON trim and a LEFT AILERON trim.
I had used 100% aileron trim on the tx. in an endevour to straighten it.
WHAT PERCENTAGES OF TRIMS ON EACH OR BOTH, DO I APPLY TO GET THE SAME TRIM SETTINGS ON THE SUB TRIM MENU SO THAT I CAN GO BACK TO THE TX. NEUTRALISE THE AILERON TRIM SETTING AND HAVE MORE TRIM AVAILABLE ?
These examples are at the extreme and I realise that on ailerons a small percentage would not make much difference but the same principle applies to other surfaces where you are using 2 servos on seperate channels. On elevators a slight uneven setting could be a problem on a accurate model.
ie. I have a very badly built model that is crooked and uses ONE aileron servo with Tx.set in NORMAL WING mode.
On flying it veers badly to the left,very bad... I start pulsing in DIGITAL right aileron trim in an endevour to correct this. I run the trim all the way to 100% right aileron trim but the model still veers to the left.
I land the model.
Being an idiot I do not know how to adjust a quick link and anyhow I have spent many hundreds of dollars on this "you beaut" computer set that does EVERYTHING.
I go into the menu.... SUB TRIM... I can now dial in 100% right trim and then neutralise the digital trim on the front of the Tx. and I am back to having a model that still veers SLIGHTly to the left. However I now have 100% travel on the aileron DIGITAL trim to straighten the model on the next flight which I do and all is OK.(please.. dont tell me I shouldn't do it this way)
NOW:
Some bright spark suggests I use TWO servos on the aileron and set the Tx. up to FLAPERON WING mode.
I fly the model and it screams over to the left as before and I bring the AILERON DIGITAL trim on the tx, over to the right to try and adjust it.
I still need more trim so I land and go into the menu again and "WOW" , I now have both a RIGHT AILERON trim and a LEFT AILERON trim.
I had used 100% aileron trim on the tx. in an endevour to straighten it.
WHAT PERCENTAGES OF TRIMS ON EACH OR BOTH, DO I APPLY TO GET THE SAME TRIM SETTINGS ON THE SUB TRIM MENU SO THAT I CAN GO BACK TO THE TX. NEUTRALISE THE AILERON TRIM SETTING AND HAVE MORE TRIM AVAILABLE ?
These examples are at the extreme and I realise that on ailerons a small percentage would not make much difference but the same principle applies to other surfaces where you are using 2 servos on seperate channels. On elevators a slight uneven setting could be a problem on a accurate model.
10-26-2009, 08:55 AM
#17
My Feedback: (2)
RE: AILERON TRIMMING.
If you have a model that is badly out of Trim, using the radio to correct the Trim problem is just a temporary solution. You need to Mechanically change the pushrod lengths and set the Trims back to Zero or fix the warp in the aircraft so that it flies True with minimal Trim adjustments.
The SubTrim is only for subtle minor Trim adjustments. It is not meant as a solution to add more Trim Adjustment when your Trim Levers are a Max.
When you make a Maiden Flight on an aircraft, finish Trimming it for Level Flight, into the wind, and Land it, the first thing you should do is look to see which direction you had to push the Trim Levers and then adjust the Control Surfaces in that direction, After that, set the Trims back to Zero.
I had a jet that suffered from a Warped Wing. It was a model that had no Ailerons, just Tailerons (flying stabs that are used to control Pitch and Roll). In order to Trim the aircraft, the Tailerons were set with so much Left Trim that it created quite a bit of Drag and slowed the aircraft down to the point where it was difficult to get decent Speed. Once I replaced the bad wing, the Trims were closer to Neutral and it flew great.
There is nothing wrong with using one Aileron servo to control both Ailerons. This is commonly done in Trainers, or aircraft that is small and cannot afford the weight of two servos. In larger aircraft, one servo for each Aileron is common. Trimming is the same basic procedure. One Aileron goes Up and the other Aileron goes Down until the model flies straight.
The SubTrim is only for subtle minor Trim adjustments. It is not meant as a solution to add more Trim Adjustment when your Trim Levers are a Max.
When you make a Maiden Flight on an aircraft, finish Trimming it for Level Flight, into the wind, and Land it, the first thing you should do is look to see which direction you had to push the Trim Levers and then adjust the Control Surfaces in that direction, After that, set the Trims back to Zero.
I had a jet that suffered from a Warped Wing. It was a model that had no Ailerons, just Tailerons (flying stabs that are used to control Pitch and Roll). In order to Trim the aircraft, the Tailerons were set with so much Left Trim that it created quite a bit of Drag and slowed the aircraft down to the point where it was difficult to get decent Speed. Once I replaced the bad wing, the Trims were closer to Neutral and it flew great.
There is nothing wrong with using one Aileron servo to control both Ailerons. This is commonly done in Trainers, or aircraft that is small and cannot afford the weight of two servos. In larger aircraft, one servo for each Aileron is common. Trimming is the same basic procedure. One Aileron goes Up and the other Aileron goes Down until the model flies straight.
10-26-2009, 12:03 PM
#18
RE: AILERON TRIMMING.
ORIGINAL: misterv
OK. let's try again and let's also assume I know how to operate a computer radio Tx. although from the replies most seem not to beleive that.
ie. I have a very badly built model that is crooked and uses ONE aileron servo with Tx.set in NORMAL WING mode.
On flying it veers badly to the left,very bad... I start pulsing in DIGITAL right aileron trim in an endevour to correct this. I run the trim all the way to 100% right aileron trim but the model still veers to the left.
I land the model.
Being an idiot I do not know how to adjust a quick link and anyhow I have spent many hundreds of dollars on this ''you beaut'' computer set that does EVERYTHING.
I go into the menu.... SUB TRIM... I can now dial in 100% right trim and then neutralise the digital trim on the front of the Tx. and I am back to having a model that still veers SLIGHTly to the left. However I now have 100% travel on the aileron DIGITAL trim to straighten the model on the next flight which I do and all is OK.(please.. dont tell me I shouldn't do it this way)
NOW:
Some bright spark suggests I use TWO servos on the aileron and set the Tx. up to FLAPERON WING mode.
I fly the model and it screams over to the left as before and I bring the AILERON DIGITAL trim on the tx, over to the right to try and adjust it.
I still need more trim so I land and go into the menu again and ''WOW'' , I now have both a RIGHT AILERON trim and a LEFT AILERON trim.
I had used 100% aileron trim on the tx. in an endevour to straighten it.
WHAT PERCENTAGES OF TRIMS ON EACH OR BOTH, DO I APPLY TO GET THE SAME TRIM SETTINGS ON THE SUB TRIM MENU SO THAT I CAN GO BACK TO THE TX. NEUTRALISE THE AILERON TRIM SETTING AND HAVE MORE TRIM AVAILABLE ?
These examples are at the extreme and I realise that on ailerons a small percentage would not make much difference but the same principle applies to other surfaces where you are using 2 servos on seperate channels. On elevators a slight uneven setting could be a problem on a accurate model.
OK. let's try again and let's also assume I know how to operate a computer radio Tx. although from the replies most seem not to beleive that.
ie. I have a very badly built model that is crooked and uses ONE aileron servo with Tx.set in NORMAL WING mode.
On flying it veers badly to the left,very bad... I start pulsing in DIGITAL right aileron trim in an endevour to correct this. I run the trim all the way to 100% right aileron trim but the model still veers to the left.
I land the model.
Being an idiot I do not know how to adjust a quick link and anyhow I have spent many hundreds of dollars on this ''you beaut'' computer set that does EVERYTHING.
I go into the menu.... SUB TRIM... I can now dial in 100% right trim and then neutralise the digital trim on the front of the Tx. and I am back to having a model that still veers SLIGHTly to the left. However I now have 100% travel on the aileron DIGITAL trim to straighten the model on the next flight which I do and all is OK.(please.. dont tell me I shouldn't do it this way)
NOW:
Some bright spark suggests I use TWO servos on the aileron and set the Tx. up to FLAPERON WING mode.
I fly the model and it screams over to the left as before and I bring the AILERON DIGITAL trim on the tx, over to the right to try and adjust it.
I still need more trim so I land and go into the menu again and ''WOW'' , I now have both a RIGHT AILERON trim and a LEFT AILERON trim.
I had used 100% aileron trim on the tx. in an endevour to straighten it.
WHAT PERCENTAGES OF TRIMS ON EACH OR BOTH, DO I APPLY TO GET THE SAME TRIM SETTINGS ON THE SUB TRIM MENU SO THAT I CAN GO BACK TO THE TX. NEUTRALISE THE AILERON TRIM SETTING AND HAVE MORE TRIM AVAILABLE ?
These examples are at the extreme and I realise that on ailerons a small percentage would not make much difference but the same principle applies to other surfaces where you are using 2 servos on seperate channels. On elevators a slight uneven setting could be a problem on a accurate model.
On my HiTec & Polk transmitters, I just get into the trim memory (whether I'm using Flaperons or 2 servos or not) and slide the trim slider back to the neutral location. That changes the memory for me. Then I save the setup and move on.
If JR isn't providing zero adjustment that's that easy (did you read the manual?) they should. Good luck,
Dave Olson
10-26-2009, 02:18 PM
#19
My Feedback: (5)
RE: AILERON TRIMMING.
Dave,
The JR doesn't need to have a trim memory adjustment as the current models memorizesall the electronic trims for a particular plane. JR had a trim memory menu on the 8103 that came with mechanical trims.
mysterv,
On the US 9303 there is a one-to-one correlation between the front trim numbers and the subtrim’s. If you have dual ailerons, the same correction should be applied to both servos. As I don’t have your model of transmitter in front of me, you will have to test this. Pick and unused model, reset it and check the MONITOR menu screen. The aileron(s) should be centered. If they aren’t, the flaperon switch may not be in neutral. Now set your front trim to an extreme. You can look at the TRIM menu (which the MONITOR menu changes to when MONITOR is highlighted and pushed) or the home screen. Either should say your aileron is at 100. Go to the Sub Trim menu and set the aileron(s) to 100 in the opposite direction. On the MONITOR menu the aileron(s) will be neutralized if your transmitter is a 9303.
Now the reasons why using either the front or the sub trim is a poor idea for correcting a warped wing. First, the transmitter has fixed end points for a channel output. Offsetting the center doesn’t change these end points. It just offsets the point where servo is positioned for a neutral stick. As you offset the center, the servo travel is limited in that direction and increased in the other. At extreme offsets the servo may stop moving in one direction before the stick is at maximum travel.
Second, trim offsetting will cause the servo arm not to be square with the linkage. This also limits the travel in the direction of the offset. It is a double whammy! Mechanically adjusting the linkage is the proper way to go. A pattern purist would say the only real way to correct the problem is to rebuild the wing or the entire plane.
Allan
The JR doesn't need to have a trim memory adjustment as the current models memorizesall the electronic trims for a particular plane. JR had a trim memory menu on the 8103 that came with mechanical trims.
mysterv,
On the US 9303 there is a one-to-one correlation between the front trim numbers and the subtrim’s. If you have dual ailerons, the same correction should be applied to both servos. As I don’t have your model of transmitter in front of me, you will have to test this. Pick and unused model, reset it and check the MONITOR menu screen. The aileron(s) should be centered. If they aren’t, the flaperon switch may not be in neutral. Now set your front trim to an extreme. You can look at the TRIM menu (which the MONITOR menu changes to when MONITOR is highlighted and pushed) or the home screen. Either should say your aileron is at 100. Go to the Sub Trim menu and set the aileron(s) to 100 in the opposite direction. On the MONITOR menu the aileron(s) will be neutralized if your transmitter is a 9303.
Now the reasons why using either the front or the sub trim is a poor idea for correcting a warped wing. First, the transmitter has fixed end points for a channel output. Offsetting the center doesn’t change these end points. It just offsets the point where servo is positioned for a neutral stick. As you offset the center, the servo travel is limited in that direction and increased in the other. At extreme offsets the servo may stop moving in one direction before the stick is at maximum travel.
Second, trim offsetting will cause the servo arm not to be square with the linkage. This also limits the travel in the direction of the offset. It is a double whammy! Mechanically adjusting the linkage is the proper way to go. A pattern purist would say the only real way to correct the problem is to rebuild the wing or the entire plane.
Allan
10-26-2009, 09:24 PM
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RE: AILERON TRIMMING.
Thanks Allan for your reply but you have missed the point entirely.
Firstly I know the JR set up backwards,forwards, sideways. I HAVE BEEN USING JR LONG BEFORE IT CAME TO US.(In fact it was my suggestion to Circus Circus to have a look at JR when they were setting up) and have been flying and trimming models for over 50 years so PLEASE no more trimming instructions. Just this technical one to clear up.
Its a long time since I used the dated 8103, and I don't think it had the facility in the menu to change individual aileron servos in the flaperon mode. The 9303 does.
You say"Go to the sub menu and set the ailerons to 100 in the opposite direction."
What I want to know is after setting the ailerons to 100 on the Tx. do I change the aileron settings in SUB TRIM by 100 on right AND left aileron, or 50 on right and left aileron. In other words does 50 down on left aileron trim and 50 up on right aileron trim, be the same as 100 down on left aileron trim.
This is only an example,at 50 or 100 you would notice the deflection on the surface but at a minor alteration it would be hard to see. However in a good model it would show up in flying.
I still fly F3A and I AM a pattern purist.
Firstly I know the JR set up backwards,forwards, sideways. I HAVE BEEN USING JR LONG BEFORE IT CAME TO US.(In fact it was my suggestion to Circus Circus to have a look at JR when they were setting up) and have been flying and trimming models for over 50 years so PLEASE no more trimming instructions. Just this technical one to clear up.
Its a long time since I used the dated 8103, and I don't think it had the facility in the menu to change individual aileron servos in the flaperon mode. The 9303 does.
You say"Go to the sub menu and set the ailerons to 100 in the opposite direction."
What I want to know is after setting the ailerons to 100 on the Tx. do I change the aileron settings in SUB TRIM by 100 on right AND left aileron, or 50 on right and left aileron. In other words does 50 down on left aileron trim and 50 up on right aileron trim, be the same as 100 down on left aileron trim.
This is only an example,at 50 or 100 you would notice the deflection on the surface but at a minor alteration it would be hard to see. However in a good model it would show up in flying.
I still fly F3A and I AM a pattern purist.
10-27-2009, 02:23 AM
#21
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RE: AILERON TRIMMING.
Assuming your transmitter works like my 9303, you should dial in the same amount of aileron trim as shown on the home page or TRIM menu to both RAIL and LAIL subtrim. An actual example, I have a new plane that isn’t trimmed yet with which I’m breaking-in an engine. Both left and right sub trims were set to zero. I used the front aileron trim to put in 12 units to the left. By changing the RAIL to L12 and the LAIL to +12 (which is left trim) and setting the front trim to zero, the ailerons are now in the same position as before. This was verified by a laser pointer lying on the ailerons and projecting onto a distant wall.
Allan
10-27-2009, 03:38 AM
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RE: AILERON TRIMMING.
Thanks Allan and RC Universe for finally finding someone that understood what I was talking about. I was beginning to think maybe I had to build another imaginary aircraft with warped wings and kwik links ,that I had to change to trim it.
The laser would certainly be the way to go and I am sure it is used when setting up dual servos on the elevator where any alteration could be drastic if not exact.
Again I thank you all for your ideas and again stress that I may be old, but not senile and still can beat a lot of "youngsters" in most, but not all, fixed wing and helis and have the silverware to prove it.
However it's not the silverware that is important but the people you meet along the way.
I have found a very good way to get help when modelling- just plead ignorant and help arrives in droves.
I know,someone will now say I am ignorant- who cares.
End of story.
Happy ending.
The laser would certainly be the way to go and I am sure it is used when setting up dual servos on the elevator where any alteration could be drastic if not exact.
Again I thank you all for your ideas and again stress that I may be old, but not senile and still can beat a lot of "youngsters" in most, but not all, fixed wing and helis and have the silverware to prove it.
However it's not the silverware that is important but the people you meet along the way.
I have found a very good way to get help when modelling- just plead ignorant and help arrives in droves.
I know,someone will now say I am ignorant- who cares.
End of story.
Happy ending.
