Hi All,

Being new to the forum I am not sure where I should place this post, so I hope I am not making a mistake placing it here. If I am then I hope someone will point me in the right direction where I might find out more about the set-up of large scale models?

I am thinking about moving up to larger scale planes and have been doing a little reading on the web. I have a few questions about what I have found and hope you can help. In particular, when it comes to having two or servos controlling one control surface. For instance, a set-up which required two servos controlling the elevators, two servos controlling the rudder, and say four on the ailerons with two each side. I understand the purpose of this is to provide enough torque to move and hold the control surface in question.

My question about this type arrangement is how are the servos wired up together, and how are they synchronized? I did see a mention of a servo synchronizer but could not find any on the web, so I think maybe I misunderstood what I was reading. The question of power also comes to mind and is it necessary to have larger power packs to deal with this? How would you guys go about this kind of set-up, and what would you use to achieve it?

Your help in understanding how this sort of set-up is done would be much appreciated.

Regards,
John

Depends on how big you're going, and what servos you're using but yes they can be ganged.

Some radios provide you the means to do it with mixing provided you have enough channels, there's also a device called a matchbox

The main thing is you want to perfectly match the stroke of each servo so that they aren't fighting each other. Digital servos can pull quite a bit of current if they are stalled so you want to make sure everything is moving the same and binding free.

I have 50cc planes that use single servos per surface (one on each aileron and elevator side of course) the mixing for the ailerons and elevators is done in the radio.

I'm going to assume you are talking about aerobatic aircraft. Keep in mind that most aerobatic aircraft up to 35% on the market only use 1 servo per elevator and if you choose your rudder servo correctly, you only need 1 there as well. So that only leave the ailerons to be ganged. I thing that BarracudaHockey left out is, if you use Hitec digitals, they can be matched using the programmer.

.

try one of these....

http://www3.towerhobbies.com/cgi-bin...&I=LXTNB1&P=ML

or one of these...

http://www3.towerhobbies.com/cgi-bin...&I=LXTNT7&P=ML

or one of these....

http://www3.towerhobbies.com/cgi-bin...&I=LXRUB8&P=ML

or even one of these....

http://www3.towerhobbies.com/cgi-bin...&I=LXAVCN&P=ML

and as a last resort... one of these...

http://www3.towerhobbies.com/cgi-bin...&I=LXCTS1&P=ML

any of the top 4 options negates the need for the bottom option.. as there are 12 proportional (or more) channels and the centers and end points for each servo can be set/adjusted on the transmitter.
If you get option 1 or 2, I can email you a setup template that you can download and install so you need only verify directions, centers and ATV's....

How'z'at?

Hi Fellows,

I have just been reading through and thinking about what you have all said. Very interesting! It seems to me from what you have said that the best way to go about this type of set-up is to make sure that you have a good radio that allows for setting up and configuring the servos to work together electronically, and this is done by programming the system. While matchboxes can be used they are not the best option. I assume this is because while they attempt the match the servos they cannot achieve this matching as well as programming does. I hope I have got this right.

As I don’t yet have the kind of radio that is required this is obviously the first thing to do. Once I have it I can then have a go at setting a few servos up on the table and see what I get. Many thanks for you comments and help and I hope I can come back to you again once I have the gear I need.

Regards,
John

Welcome John. The reason that matchbox's aren't recommended is it is another point of failure. Matchbox's do work great and will match your servos just as well as a radio would. Another option is something like the Smart-Fly EQ6. I have used it and it works great. There are lots of options out there, you will need to find the one you are comfortable with and go with it.

EQ6

Hi ericb,

Thank you for the welcome, which is much appreciated. Thank you also for the comments. I have checked out the web sites you mentioned and in particular the Smart Fly website. They have some very nice looking items there, which are very interesting and especially the EQ6 you mentioned. I would like to purchase one of these and a matchbox and just set them up on the table and have a look at them. At the moment it seems like a simple and straightforward way to go and gives me the chance to have a look at what is possible. As you say there are a lot of options to look at. Many thanks for your help and it is much appreciated.

Regards,
John

John, welcome to FG. Well if you get a good radio, like 8FG, 12Z, 14MZ, etc..you can match the servos to work perfect each other with the radio, you dont need to get power expanders, it will takes time to setup, but im the king of the person that try to learn things, how to build my airplane, so i will understand more how things work and save me time and money later.

On the radio above, the amazing thing is that you tell the radio what servo you want to act like ailerons and how many, lets say you put channel 1-4 for ailerons, 1-2 for right, and 3-4 to left, you just need to check the direction which you can change with the radio reversing feacture. The same will happen with your elevator and rudder setup. You can setup a 10 servos airplane in minutes!!!.