I would appreciate if someone could tell me the math formula used in installing aileron horns so the push rod is straight when the aileron is at full deflection. I used to have it but it has now vanished. My email address is [email protected]
Thanks Bill

Never heard of a formula being involved in the installation of the horns/push rods. I do not understand what you are after so I will check back and hopefully learn something new.

Hi Villa,
There is a mathmatical formula that tells you how far to offset the center of the aileron horn back toward the center of the servo that gives you an inline rod at full travel of the servo arm.
hope this helps. Bill

I don't understand why you need a formula.
Just run the servo to full deflection and then place the control horn so the push-rod is straight

Yup, if Einstein had built RC planes I am sure he would use a formula for linkages, but nobody I know does that [sm=bananahead.gif] Bill (no offense intended) you must be on weed! [8D]

Here are two links that explain the "Ackerman Effect" this might be the info you are looking for.

Ackernman effect

Related to vehicles
http://www.muller.net/mullermachine/docs/ackerman.html

Relating to aircraft flight controls
http://members.cox.net/bdfelice/Ackerman/ackerman.htm

That is what I have ended up doing. It is actually easier with the formula, you dont have to hook anything up or hold them in place.
Thanks Bill

You can go here:

http://jimsrc.com/Files/servcalc.xls

and download a servo torque calculator. Click on the offset and differential tab at the bottom of the spread sheet and you can model linkages.

Have a look. There is also several other neat reasources on his page.

Hope it helps

Thanks Mike this will help alot. Bill

kemper, unless your ailerons have a pull/pull setup, the ackerman theory is NOT relevant. The geometry principles described in those articles apply only in a pull pull setup situation to keep both cables under the same tension throughout the full travel of the surface

in practice tho, this is not that big of a deal as one might think- cause if one cable become a little slack (the one on opposite side of the cable under load) it is NOT a big deal... all my pull/pull setups are this way with no ill effects, you will find many posts with the same conclusion (do an "ackerman" search)

hope this helps,
vasek

Diagrammatically...

bkemper619...I still don't know what you'r after. If you are more comfortable with formulas more power to you and don't let anything I mention discourage you. It apears to me that if you understand what is needed that you can sketch it out, and from that make up any formula you need. A little geometry and some trig and you can come up with whatever formula you want to play with. Most of us just set the servo and horn at neutral, cut the rod, and play with the adjustments till it looks OK.

Hi!
Formula???
The only thing you do is to use simple geometric...90 degree angle at all posts! That's the standard set up.

Regards!
Jan K
Sweden