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Old Sep 18, 2013, 07:21 PM
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Help!
how can i trim my trainer and set dual rates & Expo

Hello guys... my plane is seagull swift 40 i dont know how to trim it and how to set dual rates & expo. . In the manual its written control throws for intial or sport flying aileron 3/8 up and down , elevator 3/8 up and down, rudder 1/2 right and left..... i dont how can i set this.. note : (i have programmable radio jr xg7)
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Old Sep 18, 2013, 07:30 PM
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Best I've got for you is read the manual.

I started out with a simple 4/channel radio and gradually made my way to a Spektrum DX6i. If this radio was my first I'd be lost.

Patience goes a loong ways in this hobby.
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Old Sep 18, 2013, 07:44 PM
JrV
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What that manual is referring to is the end point adjustment for your servo throws, meaning how far they move from neutral position(even with trailing edge) to 3/8" above and below the trailing edge of the aileron and so on for the elevator and rudder.. Did they state if those settings were full throw/high rate settings? Did it suggest a low rate setting and or expo setting in the manual?

Also dual rates are a way of reducing the throws in both direction. So say you have 100% dual rate throw = 1/2" up and down on aileron, going to 50% dual rates would be 1/4" throws up and down.
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Old Sep 18, 2013, 10:00 PM
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Originally Posted by PiperRon View Post
Best I've got for you is read the manual.

I started out with a simple 4/channel radio and gradually made my way to a Spektrum DX6i. If this radio was my first I'd be lost.

Patience goes a loong ways in this hobby.
Thanks , i have already read the manual alot of times and they didnt mention any info about this part
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Old Sep 18, 2013, 10:05 PM
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Originally Posted by JrV View Post
What that manual is referring to is the end point adjustment for your servo throws, meaning how far they move from neutral position(even with trailing edge) to 3/8" above and below the trailing edge of the aileron and so on for the elevator and rudder.. Did they state if those settings were full throw/high rate settings? Did it suggest a low rate setting and or expo setting in the manual?

Also dual rates are a way of reducing the throws in both direction. So say you have 100% dual rate throw = 1/2" up and down on aileron, going to 50% dual rates would be 1/4" throws up and down.
Thanks for the help.. they didnt mention anything about dual rates or expo setting in the manual... they only mentioned c.g and the control throws...
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Old Sep 18, 2013, 10:07 PM
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Youtube.

It usually has how tos on just about everything.
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Old Sep 18, 2013, 10:11 PM
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Originally Posted by Stradawhovious View Post
Youtube.

It usually has how tos on just about everything.

Thank you... i've already saw one before but i cant understand if the dual rates and expo setting differ or just all trainers will use same setting
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Old Sep 18, 2013, 10:15 PM
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Originally Posted by flying_rc View Post
Thank you... i've already saw one before but i cant understand if the dual rates and expo setting differ or just all trainers will use same setting
Watch a few if you can find them. Some people are much better at explaining things than others. I had to watch a handful of vids on programming elevon mixing with the DX6i before I understood it.
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Old Sep 20, 2013, 05:22 AM
Depron Daz
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Right, no one has yet given you any more than "go look at YouTube" or "read your manual" responses, which helps no one, so here goes, but let me get a cup of tea first as this will be a long response!

......Slurp...... Right, I'll start with setting the control surfaces up as close as possible to neutral. This is ALWAYS to be done mechanically at this stage. Do not use the Tx to do it at this point to adjust it, but follow what I say. First things first, turn on the Tx and put a battery in the plane to turn on the Rx and arm the servos. Now check that the aileron trim is centred exactly at 0. If not, then adjust the trim to 0. All you have done at this stage is to clarify that the servo is dead centre, don't worry about the aileron position. Remember that aileron, elevator and rudder trim 0 is at its centre point, not all the way down or all the way up, but centre, as these surfaces move in both directions.
Right, unplug your flight battery. Now with your aileron, take a straight edge like a ruler, and find the centre line at the end of the wing by holding it against it. Now see where the centre line of the aileron is in comparison the centre line of the wing. If the aileron is say sticking up at the trailing edge, then you need to adjust the control rod. Hopefully your control rod will have an adjustable clevis at one or both ends. If not it may be beneficial for you to buy enough to do all surfaces. Now with the aileron servo in it's current centred position (remember we set the trims to 0) wind in or out the clevis to get the aileron centre line in line with the centre line of the wing. Try and get this as close as physically (mechanically) possible. If you cannot get it absolutely spot on, then and ONLY then, use the sub trim in the servo menu on the Tx to get it spot on. Do this with all control surfaces. The plane's control surfaces are now mechanically set.
When you first fly your plane, you may need to use the trim tabs next to the stick to aerodynamically trim the plane in flight. This is the important and final trimming that you will need to do. A plane on a table may look trimmed, and all the numbers may match when measured, but that doesn't mean diddly squat when the plane is flying.

Moving on to dual rates and the misconception which some people have differentiating between this and Expo. Dual rates and expo are not the same thing. FACT

Dual rates (D/R) allows you to set different amounts of final control surface movement, regardless of what expo has been set (come to that in a minute). So, we will keep this VERY simple, so lets say you have set 50% on the first rate, and 100% on the second rate. Now, place the plane on a flat surface like a dining table, and take a ruler or a tape measure. Place the ruler on it's end at the back edge (it's called the trailing edge) of the surface that you are checking (aileron, flaps or elevator). Now, with the switch that you have selected to use to operate your D/Rs, set it to position one, and operate the control stick for that particular surface, lets say the aileron. And, lets just say that at the moment, the aileron moves 7mm up the ruler. When you move the stick in the opposite direction, you should also get 7mm of movement. If you don't, go into your travel adjustment for that particular servo, and adjust it's travel until you get 7mm on the ruler, and save this. DO NOT USE THE TRIMS NEXT TO THE STICK, THESE ARE FOR IN-FLIGHT ADJUSTMENTS. That should now have your first dual rate set.. Now flick the switch to check your 2nd rate. This will have twice the travel naturally, and should be as near as damn it to 14mm in both directions. Remember, do not adjust the trims again as this will throw out the first trim adjustment you made in D/R 1. That is now both D/Rs set.
If your manual says that the aileron is best to move 1/8th", then you need to play around with the D/R percentage to achieve 1/8th", or 3mm depending on whether you are imperial or metric minded. Hopefully that makes sense so far? The manuals generally show two D/Rs, one for beginners and one for experienced pilots. Or, they'll say like trainer and aerobatic, whatever it doesn't matter. You'll find that as you fly it more and more, and your level grows, you may want to adjust these rates to 75% and 100%, it's up to you.
Now where some people get confused, if you set 50% for the first D/R, if the stick was moved half way, then you will have only an eighth of its possible travel, half way = 25%, three quarters = 50% and so on. Flick it to the second D/R set to 100%, and at quarter stick you will have quarter of final deflection, and so on.....
Now, some basic Tx's don't have travel adjustment or D/Rs, so you have to adjust the flight surface control rod by moving the rod to different holes on the horns on both the servo or the surface horn, in order to achieve that required amount of movement. Does that make sense?

Moving on, and this is what sometimes confuses some people. Expo changes the way a servo responds to the movement of the Tx stick. It makes the servo respond either more or less rapidly (softens or harshens) around the stick centre point increasing or decreasing the sensitivity around the neutral position. It does not effect the final position of the servo in relation to the Tx stick, which is what dual rate does. So, set 0% on Expo (effectively having NO expo), and you will find that from the stick centre point, and as soon as you move the stick, the surface moves comparatively with the stick movement, quarter stick = quarter surface movement and so on according to the D/R setting that you have just set, and that this movement is linear, so if you have a screen graph on the Tx like Spektrums have, then you will see a dead straight 45 deg line going from 0-100. Just quickly going back to the 7mm that you set (hypothetically), that 1/4 stick movement should give you around 1.75mm travel.
Now, if you put in say 30% Expo, keeping it simples still, the stick's movement, from it's centre point, will not be as sensitive as it was when set at 0%. You will have less surface travel at the start of the movement of the stick, which gets progressively more sensitive as it moves along the linear graph AWAY from the stick centre point towards full movement. As you move the stick to it's fullest end point, the surface becomes more and more sensitive until you reach full travel which will be like as if you had 0% Expo, and when you reach the end of the stick movement you should now have 7mm of surface travel (or whatever D/R 1 which you set earlier). I'm afraid it becomes too mathematical for me to quote actual figures (and I've just got up from doing my final night shift and am still not fully in the land of the living) as the movement throughout is exponential, and not dead straight linear.

So, as a beginner I would set your expo to a percentage where the plane isn't violent when the stick is moved slightly from the neutral point. Generally on a new plane I tend to set 40-50% expo, and after the first flight I will bring this down, and again maybe on the next flight and so on, until my style of flying doesn't make it act violently.
Same with my D/R's, I tend to use 60-70% on the first and 100% on the second.
Your Tx may also have the ability to use over 100% travel adjustment on the servos, to get even more travel, but for now just keep it simple.



Right, I need a strong coffee now, hope this helps ya!
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Old Sep 20, 2013, 07:32 AM
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Originally Posted by Stradawhovious View Post
Watch a few if you can find them. Some people are much better at explaining things than others. I had to watch a handful of vids on programming elevon mixing with the DX6i before I understood it.
I know how to set them on my tx , the main point is that i didnt know the percantages and whats the use of it
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Old Sep 20, 2013, 07:36 AM
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Originally Posted by Daz393 View Post
Right, no one has yet given you any more than "go look at YouTube" or "read your manual" responses, which helps no one, so here goes, but let me get a cup of tea first as this will be a long response!

......Slurp...... Right, I'll start with setting the control surfaces up as close as possible to neutral. This is ALWAYS to be done mechanically at this stage. Do not use the Tx to do it at this point to adjust it, but follow what I say. First things first, turn on the Tx and put a battery in the plane to turn on the Rx and arm the servos. Now check that the aileron trim is centred exactly at 0. If not, then adjust the trim to 0. All you have done at this stage is to clarify that the servo is dead centre, don't worry about the aileron position. Remember that aileron, elevator and rudder trim 0 is at its centre point, not all the way down or all the way up, but centre, as these surfaces move in both directions.
Right, unplug your flight battery. Now with your aileron, take a straight edge like a ruler, and find the centre line at the end of the wing by holding it against it. Now see where the centre line of the aileron is in comparison the centre line of the wing. If the aileron is say sticking up at the trailing edge, then you need to adjust the control rod. Hopefully your control rod will have an adjustable clevis at one or both ends. If not it may be beneficial for you to buy enough to do all surfaces. Now with the aileron servo in it's current centred position (remember we set the trims to 0) wind in or out the clevis to get the aileron centre line in line with the centre line of the wing. Try and get this as close as physically (mechanically) possible. If you cannot get it absolutely spot on, then and ONLY then, use the sub trim in the servo menu on the Tx to get it spot on. Do this with all control surfaces. The plane's control surfaces are now mechanically set.
When you first fly your plane, you may need to use the trim tabs next to the stick to aerodynamically trim the plane in flight. This is the important and final trimming that you will need to do. A plane on a table may look trimmed, and all the numbers may match when measured, but that doesn't mean diddly squat when the plane is flying.

Moving on to dual rates and the misconception which some people have differentiating between this and Expo. Dual rates and expo are not the same thing. FACT

Dual rates (D/R) allows you to set different amounts of final control surface movement, regardless of what expo has been set (come to that in a minute). So, we will keep this VERY simple, so lets say you have set 50% on the first rate, and 100% on the second rate. Now, place the plane on a flat surface like a dining table, and take a ruler or a tape measure. Place the ruler on it's end at the back edge (it's called the trailing edge) of the surface that you are checking (aileron, flaps or elevator). Now, with the switch that you have selected to use to operate your D/Rs, set it to position one, and operate the control stick for that particular surface, lets say the aileron. And, lets just say that at the moment, the aileron moves 7mm up the ruler. When you move the stick in the opposite direction, you should also get 7mm of movement. If you don't, go into your travel adjustment for that particular servo, and adjust it's travel until you get 7mm on the ruler, and save this. DO NOT USE THE TRIMS NEXT TO THE STICK, THESE ARE FOR IN-FLIGHT ADJUSTMENTS. That should now have your first dual rate set.. Now flick the switch to check your 2nd rate. This will have twice the travel naturally, and should be as near as damn it to 14mm in both directions. Remember, do not adjust the trims again as this will throw out the first trim adjustment you made in D/R 1. That is now both D/Rs set.
If your manual says that the aileron is best to move 1/8th", then you need to play around with the D/R percentage to achieve 1/8th", or 3mm depending on whether you are imperial or metric minded. Hopefully that makes sense so far? The manuals generally show two D/Rs, one for beginners and one for experienced pilots. Or, they'll say like trainer and aerobatic, whatever it doesn't matter. You'll find that as you fly it more and more, and your level grows, you may want to adjust these rates to 75% and 100%, it's up to you.
Now where some people get confused, if you set 50% for the first D/R, if the stick was moved half way, then you will have only an eighth of its possible travel, half way = 25%, three quarters = 50% and so on. Flick it to the second D/R set to 100%, and at quarter stick you will have quarter of final deflection, and so on.....
Now, some basic Tx's don't have travel adjustment or D/Rs, so you have to adjust the flight surface control rod by moving the rod to different holes on the horns on both the servo or the surface horn, in order to achieve that required amount of movement. Does that make sense?

Moving on, and this is what sometimes confuses some people. Expo changes the way a servo responds to the movement of the Tx stick. It makes the servo respond either more or less rapidly (softens or harshens) around the stick centre point increasing or decreasing the sensitivity around the neutral position. It does not effect the final position of the servo in relation to the Tx stick, which is what dual rate does. So, set 0% on Expo (effectively having NO expo), and you will find that from the stick centre point, and as soon as you move the stick, the surface moves comparatively with the stick movement, quarter stick = quarter surface movement and so on according to the D/R setting that you have just set, and that this movement is linear, so if you have a screen graph on the Tx like Spektrums have, then you will see a dead straight 45 deg line going from 0-100. Just quickly going back to the 7mm that you set (hypothetically), that 1/4 stick movement should give you around 1.75mm travel.
Now, if you put in say 30% Expo, keeping it simples still, the stick's movement, from it's centre point, will not be as sensitive as it was when set at 0%. You will have less surface travel at the start of the movement of the stick, which gets progressively more sensitive as it moves along the linear graph AWAY from the stick centre point towards full movement. As you move the stick to it's fullest end point, the surface becomes more and more sensitive until you reach full travel which will be like as if you had 0% Expo, and when you reach the end of the stick movement you should now have 7mm of surface travel (or whatever D/R 1 which you set earlier). I'm afraid it becomes too mathematical for me to quote actual figures (and I've just got up from doing my final night shift and am still not fully in the land of the living) as the movement throughout is exponential, and not dead straight linear.

So, as a beginner I would set your expo to a percentage where the plane isn't violent when the stick is moved slightly from the neutral point. Generally on a new plane I tend to set 40-50% expo, and after the first flight I will bring this down, and again maybe on the next flight and so on, until my style of flying doesn't make it act violently.
Same with my D/R's, I tend to use 60-70% on the first and 100% on the second.
Your Tx may also have the ability to use over 100% travel adjustment on the servos, to get even more travel, but for now just keep it simple.



Right, I need a strong coffee now, hope this helps ya!
Really thank you so much, you helped me with everything i need... you gave me all information that i would try to search about it in hours you made me understand everything in few minutes... i ve set everything about control throws but i didnt know its name.. but you taught me everything about dual rates and expo .. again thank you friend for that great help
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Old Sep 20, 2013, 08:37 AM
Depron Daz
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Joined Feb 2012
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Originally Posted by flying_rc View Post
I know how to set them on my tx , the main point is that i didnt know the percantages and whats the use of it
You are welcome, but just be aware that the percentages shown on your Tx in expo and D/Rs, are percentages of IT'S capability, not the planes.
You set the percentages which are dependent on each individual plane if you have model memory within. So, 50% D/R on one planes ailerons will give you a different travel end point than on say another. I have planes that have 70% as a base, and others that are only set to 100% as a base, simply because below 100% and the plane isn't as flyable.

It's the same with Expo. Most of mine are set at +30, but a few are higher as they are twitchier. Don't forget that Spektrum, Orange & JR radios are positive expo for better control, and Futaba and some others are negative expo for better control.

I can only give advice and say start out at XYZ, but you the pilot have to then work from there to find your best settings. Again, the manufacturers state to set ailerons at say 10mm (+/- 1%) as an example, but that is just a basic set up. Another pilot may set it at 8mm and be happy, whereas another may want 12mm, where both are above or below the manufacturers recommendations, do you see what I'm saying? Nothing is set in stone apart from the plane's Centre of Gravity, but again that has a viable margin too, but that is a whole different story!
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Old Sep 20, 2013, 08:54 AM
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Originally Posted by flying_rc View Post
I know how to set them on my tx , the main point is that i didnt know the percantages and whats the use of it
Ok, your original post stated you didn't know how to set them.

I'm glad you found the answer you were looking for
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Old Sep 20, 2013, 11:41 AM
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The short answer is that you don't need dual rates and expo on a trainer. As a matter of fact, dual ratel and expo on a trainer are probably detrimental.

Larry
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Old Sep 20, 2013, 03:17 PM
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Originally Posted by Lnagel View Post
The short answer is that you don't need dual rates and expo on a trainer. As a matter of fact, dual ratel and expo on a trainer are probably detrimental.

Larry
Thank you larry
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