Kmot

My Feedback: (24)

OK, I know this is wrong. [&o]

But refresh my memory. What happens when the linkage is not square?

I have a problem. If I make the elevator linkage square, it runs smack into the rudder pull-pull linkage.

So it looks like I will have to have it at some sort of angle. This screw is too short, I can put in a longer screw to lower down the rod but I don't think I will be able to keep square,

scale only 4 me

My Feedback: (158)

You definitely need a longer screw, just to have proper leverage
It may create a little differential, but nothing a computer radio can't adjust for,, you'll be fine

andrew wisc.

My Feedback: (4)

hard to tell from pick, but can you rotate servo arm 180 degrees or will it then interfere with horizontal stab? seems like they could of had hole located down further and then arm would be in line with elevator horn when servo arm pointing up towards stab.

da Rock

You're trying to make too many things square. Only two things need to be square. Both square up with the pushrod.

The pushrod should make a right angle with the servo arm. The servo arm does not have to be square to the servo case. In fact, the servo case means nothing at all to the rigging of your model. When you're setting up your rigging, at the very start, turn on your TX and RX and center all trims. Then make sure all centering is at zero. Everything works from there. To set up every servo arm on every surface the next step for each is to hold that pushrod where you figure it'll wind up when the surface is at neutral. THEN put the servo arm on the servo gear so the arm will make a right angle to the pushrod. Your first picture shows the servo arm pointing straight down. It won't make a right angle with the pushrod pointing down like that. The pushrod is going to point up at the elevator horn, not straight back. And the right angle required if between the rod and the arm, not the arm and the servo.

OK so far?

NOW comes the tough part to explain. So I'm going to go look for some pictures. The style elevator horn you have is going to cause a lot of explaining.

OH BTW...... lots of designs position the elevator servo lower and run the arm up instead of down. They do it that way on purpose. You've just discovered that purpose.

edit I decided to use your picture instead.

da Rock

At the elevator horn, where the connecting rod attaches, is an important location.

If you draw a line along the rod to the point where it connects to the horn, if you then continue drawing to the hinge line, the line you're drawing should have a right angle in it.

The rod should make a right angle with the servo arm, and at the elevator horn connection. Those are the 2 right angles that should be made ever time you rig a servo to a surface.

OK, I decided to just draw the two required right angles on your picture.

Looks like moving your servo arm a couple of teeth will solve the problem.

da Rock

BTW, the reason you want the servo arm to make a right angle with the pushrod is to not have a problem that happens when we try to turn a rotary motion into straight-line motion. When we use a rotating servo arm to push and pull a pushrod, if there isn't a right angle then there is a longer push and a shorter pull, or vice versa.

Fixing it with the radio works, but only if we don't need to push or pull very far. If we do, and fix it with the radio using the adjustments we paid for, the radio winds up not giving us the accuracy we paid for. It doesn't take any longer to rig the model right than it does rigging it wrong. And we get flying accuracy we paid for from the radio.

Kmot

My Feedback: (24)

Cool, thanks!

Gray Beard

My Feedback: (-1)

What happens if you reverse the servo arm???

Kmot

My Feedback: (24)

Gonna try that, as well as all the other tips.

But, this is not the servo arm I intend to use. This was just to get an idea of how much I would need to cut the rod. Then I got all discombobulated by the angle of the dangle.

Kmot

My Feedback: (24)

You know the expression, "can't see the forest for the trees"?

Sometimes the simplest answer is just a blank.

Thanks again for everyone's input, and especially Andrew. Simply rotating the servo arm 180° did the trick.

Again, this is just a trial run and not the final gear that will be used but it gives me some info I need.