discussion Rudders & servos

[Guest]

Help, i am having a "CRAFT" day, ( Cant Remember A F....... Thing ). Having difficulty lining up my rudder and servo so i get equal movement either way. I am tight for space, what are the most important issues. I should know but as i said, having a "CRAFT" day.

All sugestions gratefully received.

JohnHA.

 

[Guest]

Boat or plane? I guess it doesn't really matter.

The most important thing is to start off in the servo's central position and place the horn in the central neutral position. You need power on, radio on and don't forget to put the trim tab in it's central position as well!!

With the rudder in the neutral position measure up for the linkage and lay it in place. You want the linkage to be as close to 90 deg as possible to the rod otherwise you will get an uneven throw. I know that this is sometimes desirable for ailerons (ask Barry for details!) but not for rudders.

You will almost certainly end up adjusting the trim tab but if you start off with all these points you should not have to make much of an adjustment.

 

[Guest]

As BB says, remember the trims.

And for boats, anything over 35% rudder movement is generally a waste of time.

J.

 

[wonwinglo]

Not sure what make of servos that you are using but on some the resolution is not always equal either way,check for gear slop or backlash with the equipment switched on grip the servo arm and gently try and see if it moves,if it does then it could be worn gears.

More expensive servos obviously have better tolerances.

Richard is referring to differential aileron horns but I do not think they are used in your model boats.

Also make sure that your linkages are in line,if they wander off then you will get two different rudder settings.

Try those for starters.

 

[Guest]

Thanks guys, sorry i forgot to mention it is a boat rudder & servo.

Will re-examine with all your comments where applicable & report back.

JohnHA

 

[Guest]

Sorry guys it's me again, another thing i forgot to mention is that the rudder horn is looking one way but because of restricted servo space it's horn is looking in the opposite direction. Thanks again.

JohnHA

 

[Guest]

if space really is a premium you can always use a flexi link and locate the servo further away from the rudder..... the flexi links and like those used in model aircraft, you need two - obviously one to push and one to pull, but can be done easily, the flexi link is a cable in a sleve to which clevis can be attatched.....

 

[Guest]

I used exactly that method of driving the twin rudders of the Revell U-Boat as per the pictures below.

There is no reason however why you cannot place the servo arm at any attitude to the servo as long as it is centralised and at 90 degrees to the linkage when at neutral. It must, of course, travel equally either side of the neutral but the horn could be mounted in line with the servo or perpendicular to it on either side. It really doesn't matter.

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[Guest]

spot on bunk......