Setting Up Ailerons with Two Servos
#1
Thread Starter
Setting Up Ailerons with Two Servos
We have an Aeroworks 30 cc Extra which is controlled with a Futaba 14SG radio system. It flies reasonably well but when trying to hover it we found it to be somewhat out of tune as it were. So we checked the Ailerons via a throw meter and found differences in the movement between them and with the throws even on one side. Not good, so we decided to rerig the whole affair and proceeded as follows:
We set the aileron subtrim on the transmitter to zero and then via the mechanical linkages set the ailerons as close to the central point as possible which we then fine tuned with a small amount of subtrim:-- The linkage mechanism looks to be the same on both sides and accurately set. Each aileron has its own servo and channel.
The next step was to set up three dual rates at 20, 30 and 40 degrees respectively. At full rate we got an even throw up and down (40 deg) on the aileron, checked with a throw meter. But when we then set the middle rate, we found that the aileron when going down will only reach about 25 deg or so but will go up to 30 degrees. Same when you set in the lowest rate...the up and down throws are not quite the same. And then there is the Aileron on the opposite side to add into the mix.
So if anyone could recommend or tell us the best way to go about resolving this issue I would be most grateful. With the 14SG and all of its functions, what is the best way to accurately set up aileron throw on an aircraft like this across three rates. My initial thought was that there must be a linkage problem but that does not seem to be the case and one would think that even if there was a slight difference in the linkages you should be able to offset it via the radio adjustments.
Many Thanks
Paul
We set the aileron subtrim on the transmitter to zero and then via the mechanical linkages set the ailerons as close to the central point as possible which we then fine tuned with a small amount of subtrim:-- The linkage mechanism looks to be the same on both sides and accurately set. Each aileron has its own servo and channel.
The next step was to set up three dual rates at 20, 30 and 40 degrees respectively. At full rate we got an even throw up and down (40 deg) on the aileron, checked with a throw meter. But when we then set the middle rate, we found that the aileron when going down will only reach about 25 deg or so but will go up to 30 degrees. Same when you set in the lowest rate...the up and down throws are not quite the same. And then there is the Aileron on the opposite side to add into the mix.
So if anyone could recommend or tell us the best way to go about resolving this issue I would be most grateful. With the 14SG and all of its functions, what is the best way to accurately set up aileron throw on an aircraft like this across three rates. My initial thought was that there must be a linkage problem but that does not seem to be the case and one would think that even if there was a slight difference in the linkages you should be able to offset it via the radio adjustments.
Many Thanks
Paul
Last edited by pbeck39; 06-25-2015 at 10:56 AM.
#2
My Feedback: (3)
Having more up than down is not necessarily a problem, and in fact many (most?) planes turn better and roll more axially this way (i.e., with aileron differential). If it bothers you, it is likely caused by the control horn linkage attach point not being directly over the hinge line or the servo arm not being exactly perpendicular to the linkage at neutral.
To set up a wing, I do the following:
1. Set the Subtrims to 0
2. Set the End Point Adjustments to halfway between 100% and the max (i.e., about 120%)
3. Make sure the control horn linkage attach points are the same relative to the hinge line (distance both fore/aft and up/down)
4. Set the servo arm neutral position so that it is perpendicular to the linkage arm (probably can't get it exact unless its a programmable servo, so use Subtrim to get them the same)
5. Use Aileron DIfferential to achieve axial rolls on an upline (i.e., plane does not walk left or right when rolling)
To set up a wing, I do the following:
1. Set the Subtrims to 0
2. Set the End Point Adjustments to halfway between 100% and the max (i.e., about 120%)
3. Make sure the control horn linkage attach points are the same relative to the hinge line (distance both fore/aft and up/down)
4. Set the servo arm neutral position so that it is perpendicular to the linkage arm (probably can't get it exact unless its a programmable servo, so use Subtrim to get them the same)
5. Use Aileron DIfferential to achieve axial rolls on an upline (i.e., plane does not walk left or right when rolling)
#3
In the past when it got to the point I was ready to throw the transmitter (either aileron servos or, more commonly split elevators) I used a Smart Fly equalizer to match two servos. They allow very fine adjustments.
http://smart-fly.com/index.php?route...tegory&path=71
http://smart-fly.com/index.php?route...tegory&path=71